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SURVEYING SURVEYING Introduction Introduction
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Page 1: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

SURVEYINGSURVEYING

IntroductionIntroduction

Page 2: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Introduction to SurveyingIntroduction to Surveying

►DefinitionDefinition::

Surveying is the science and art of Surveying is the science and art of determining the relative positions of determining the relative positions of points above, on, or beneath the points above, on, or beneath the earth’s surface and locating the points earth’s surface and locating the points in the field.in the field.

Page 3: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

The work of the surveyor The work of the surveyor consists of 5 phases:consists of 5 phases:

1.1. Decision Making – selecting method, equipment Decision Making – selecting method, equipment and final point locations.and final point locations.

2.2. Fieldwork & Data Collection – making Fieldwork & Data Collection – making measurements and recording data in the field.measurements and recording data in the field.

3.3. Computing & Data Processing – preparing Computing & Data Processing – preparing calculations based upon the recorded data to calculations based upon the recorded data to determine locations in a useable form.determine locations in a useable form.

4.4. Mapping or Data Representation – plotting data Mapping or Data Representation – plotting data to produce a map, plot, or chart in the proper to produce a map, plot, or chart in the proper form.form.

5.5. Stakeout – locating and establishing Stakeout – locating and establishing monuments or stakes in the proper locations in monuments or stakes in the proper locations in the field.the field.

Page 4: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Object of SurveyingObject of Surveying

►The primary object of survey is the The primary object of survey is the preparation of plan of estate or buildings preparation of plan of estate or buildings roads, railways, pipelines, canals, etc. Or roads, railways, pipelines, canals, etc. Or to measure area of field, state, nation.to measure area of field, state, nation.

►Object of geodetic surveying is to Object of geodetic surveying is to determine precise positions on the determine precise positions on the surface of the earth of widely distant surface of the earth of widely distant points.points.

Page 5: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Uses of SurveyingUses of Surveying

►To prepare a topographical map this shows the To prepare a topographical map this shows the hills, valley, rivers, villages, town, etc, of a country.hills, valley, rivers, villages, town, etc, of a country.

►To prepare a cadastral map showing the To prepare a cadastral map showing the boundaries of fields houses, and other properties.boundaries of fields houses, and other properties.

►To prepare an engineering map to show details like To prepare an engineering map to show details like roads, railways, canals, etc.roads, railways, canals, etc.

► ..

Page 6: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Uses of SurveyingUses of Surveying

►To prepare military map showing roads and railways, To prepare military map showing roads and railways, communication with different parts of country.communication with different parts of country.

►To prepare contour map and to determine capacity of a To prepare contour map and to determine capacity of a reservoirs and ton find the best possible route for roads, reservoirs and ton find the best possible route for roads, railways etc. railways etc.

►To prepare archeological map including places where To prepare archeological map including places where ancient relics exist.ancient relics exist.

►To prepare a geological map showing areas including To prepare a geological map showing areas including underground resourcesunderground resources

Page 7: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Types of Surveying Types of Surveying

ClassificationClassification

Page 8: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

A.A. Primary Classification or Primary Classification or Primary Division : Primary Division :

1. 1. Plane surveyingPlane surveying

2. 2. Geodetic surveyingGeodetic surveying

Page 9: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

1. Plane Surveying1. Plane Surveying The shape of the earth is spherical. Thus The shape of the earth is spherical. Thus

the surface is obviously curved. But in the surface is obviously curved. But in plane surveying the curvature of earth is plane surveying the curvature of earth is not taken into account. This is because not taken into account. This is because plane surveying is carried out over a plane surveying is carried out over a small area, so the surface of the earth is small area, so the surface of the earth is considered as a plane. The degree of considered as a plane. The degree of accuracy required in this type of accuracy required in this type of surveying is completely low. Plane surveying is completely low. Plane surveying is done on an area of less than surveying is done on an area of less than 250 sq.km.250 sq.km.

Page 10: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

2. Geodetic surveying 2. Geodetic surveying

In geodetic surveying the curvature of In geodetic surveying the curvature of the earth is taken into consideration. It the earth is taken into consideration. It is extended over a large area greater is extended over a large area greater than 250 sq.km. The line joining any than 250 sq.km. The line joining any two points considered as a curved line. two points considered as a curved line. Very refined methods and instruments Very refined methods and instruments are used in this type of surveying. In are used in this type of surveying. In this method very high precision or this method very high precision or accuracy is required.accuracy is required.

Page 11: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

B. B. Secondary Classification Secondary Classification ►Survey can be classified on different Survey can be classified on different

bases:bases:

1. Based on instrument:1. Based on instrument:►Chain SurveyChain Survey►Compass surveyCompass survey►Plane Table surveyPlane Table survey►Theodolite surveyTheodolite survey►Tacheometric SurveyTacheometric Survey►Photographic surveyPhotographic survey

Page 12: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

2. Based on methods:2. Based on methods:

►Triangulation SurveyTriangulation Survey

►Traverse SurveyTraverse Survey

Page 13: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

3. Based on Objects:3. Based on Objects:

►Geological surveyGeological survey

►Mine surveyMine survey

►Archeological SurveyArcheological Survey

►Military survey Military survey

Page 14: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

4. Based on nature of field4. Based on nature of field

►Land SurveyLand Survey

►Marine surveyMarine survey

►Astronomical surveyAstronomical survey

Page 15: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Other Types of Surveys:Other Types of Surveys:

1.1. PhotogrammetryPhotogrammetry – mapping utilizing data – mapping utilizing data obtained by camera or other sensors carried in obtained by camera or other sensors carried in airplanes or satellites.airplanes or satellites.

2.2. Boundary SurveyingBoundary Surveying – establishing property – establishing property corners, boundaries, and areas of land parcels.corners, boundaries, and areas of land parcels.

3.3. Control Surveying Control Surveying – establish a network of – establish a network of horizontal and vertical monuments that serve as horizontal and vertical monuments that serve as a reference framework for other survey projects.a reference framework for other survey projects.

4.4. Engineering Surveying Engineering Surveying – providing points and – providing points and elevations for the building Civil Engineering elevations for the building Civil Engineering projects.projects.

Page 16: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Other Types of Surveys:Other Types of Surveys:

5.5. Topographic Surveying Topographic Surveying – collecting data and – collecting data and preparing maps showing the locations of preparing maps showing the locations of natural man-made features and elevations of natural man-made features and elevations of points of the ground for multiple uses.points of the ground for multiple uses.

6.6. Route Surveys Route Surveys – topographic and other – topographic and other surveys for long – narrow projects associated surveys for long – narrow projects associated with Civil Engineering projects.with Civil Engineering projects.

Highways, railroads, pipelines, and transmission Highways, railroads, pipelines, and transmission lines.lines.

7.7. Hydrographic Surveying Hydrographic Surveying – mapping of – mapping of shorelines and the bottom of bodies of water.shorelines and the bottom of bodies of water.

5.5. Also known as bathymetric surveying.Also known as bathymetric surveying.

Page 17: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Brief History of SurveyingBrief History of Surveying::

1.1. Surveying had it’s beginning in Egypt about Surveying had it’s beginning in Egypt about 1400 BC1400 BC

Land along the Nile River was divided for taxation. Land along the Nile River was divided for taxation. Divisions were washed away by annual floods.Divisions were washed away by annual floods.

““ROPE-STRETCHERS” Egyptian surveyors were ROPE-STRETCHERS” Egyptian surveyors were created to relocate the land divisions created to relocate the land divisions (measurements were made with ropes having (measurements were made with ropes having knots at unit distances).knots at unit distances).

Extensive use of surveying in building of Egyptian Extensive use of surveying in building of Egyptian monumentsmonuments

2.2. Greeks: expanded Egyptian work and Greeks: expanded Egyptian work and developed Geometry.developed Geometry.

Developed one of the earliest surveying Developed one of the earliest surveying instruments – Diopter (a form of level).instruments – Diopter (a form of level).

Page 18: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Brief History of Surveying:Brief History of Surveying:

3.3. Romans: developed surveying into a science Romans: developed surveying into a science to create the Roman roads, aqueducts, and to create the Roman roads, aqueducts, and land division systems.land division systems.

Surveyors held great power, had schools and a Surveyors held great power, had schools and a professional organizationprofessional organization

Developed several instruments:Developed several instruments:• Groma – cross instrument used to determine lines and Groma – cross instrument used to determine lines and

right anglesright angles• Libella – “A” frame with a plumb bob used for levelingLibella – “A” frame with a plumb bob used for leveling• Chorobates – 20’ straight edge with oil in notch for levelingChorobates – 20’ straight edge with oil in notch for leveling

4.4. Middle Ages: Land division of Romans Middle Ages: Land division of Romans continued in Europe.continued in Europe.

Quadrans – square brass frame capable of turning Quadrans – square brass frame capable of turning angles up to 90° and has a graduated scale angles up to 90° and has a graduated scale developed by an Italian named Von Piso.developed by an Italian named Von Piso.

Page 19: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Brief History of Surveying:Brief History of Surveying:

5.5. 18th & 19th Century in the New World: the 18th & 19th Century in the New World: the need for mapping and marking land claims need for mapping and marking land claims caused extensive surveying, especially by the caused extensive surveying, especially by the English.English.

1785: United Stated began extensive surveys of 1785: United Stated began extensive surveys of public lands into one mile square sectionspublic lands into one mile square sections

• 30 states surveyed under the U.S. Public Land System 30 states surveyed under the U.S. Public Land System (also called the Rectangular System) (also called the Rectangular System)

1807: United States Geological Survey founded to 1807: United States Geological Survey founded to establish an accurate control network and mappingestablish an accurate control network and mapping

Famous American Surveyors: George Washington, Famous American Surveyors: George Washington, Thomas Jefferson, George Rogers Clark, Abe Thomas Jefferson, George Rogers Clark, Abe Lincoln and many more.Lincoln and many more.

Page 20: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Brief History of Surveying:Brief History of Surveying:

6.6. 2020thth Century and Beyond: As technology Century and Beyond: As technology advanced, population increased, and land advanced, population increased, and land value caused development of licensure for value caused development of licensure for surveyors in all states.surveyors in all states.

Educational requirements for licensure began in Educational requirements for licensure began in the early 1990’sthe early 1990’s

Capable of electronic distance measurement, Capable of electronic distance measurement, positioning using global positioning systems, positioning using global positioning systems, construction machine control, and lidar (scanning) construction machine control, and lidar (scanning) mappingmapping

Involvement in rebuilding of the infrastructure and Involvement in rebuilding of the infrastructure and geographic information systems (GIS)geographic information systems (GIS)

Shortage of licensed professionals is projected well Shortage of licensed professionals is projected well into the 21into the 21stst century century

Page 21: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Measurement of DistanceMeasurement of Distance

► Linear measurement is the basis of all surveying and Linear measurement is the basis of all surveying and even though angles may be read precisely, the length even though angles may be read precisely, the length of at least one line in a tract must be measured to of at least one line in a tract must be measured to supplement the angles in locating points.supplement the angles in locating points.

►Old surveys were often measured using a Surveyors Old surveys were often measured using a Surveyors Chain. These were literally chains made up of 100 Chain. These were literally chains made up of 100 links. Each Chain was 66 feet long. Each link was links. Each Chain was 66 feet long. Each link was 0.666 of a foot.0.666 of a foot.

Page 22: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Units of MeasurementUnits of Measurement

►AcreAcre - The (English) acre is a unit of area - The (English) acre is a unit of area equal to 43560 square feet, or 10 square equal to 43560 square feet, or 10 square chains. A square mile is 640 acres. The chains. A square mile is 640 acres. The Scottish acre is 1.27 English acres. Scottish acre is 1.27 English acres.

►ChainChain - Unit of length usually understood - Unit of length usually understood to be Gunter's chain, from the heavy metal to be Gunter's chain, from the heavy metal chain of 100 links that was used by chain of 100 links that was used by surveyors to measure property bounds.surveyors to measure property bounds.

Page 23: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Units of MeasurementUnits of Measurement

►HectareHectare - Metric unit of area equal to - Metric unit of area equal to 10,000 square meters, or 2.471 acres. 10,000 square meters, or 2.471 acres.

►LinkLink - Unit of length equal to 1/100 - Unit of length equal to 1/100 chain (7.92 inches).chain (7.92 inches).

►Rood Rood -- Unit of area usually equal to Unit of area usually equal to 1/4 acre.1/4 acre.

►Engineer's ChainEngineer's Chain - A 100 foot - A 100 foot chain containing 100 links of one foot chain containing 100 links of one foot a piece.a piece.

Page 24: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Units of MeasurementUnits of Measurement

►FurlongFurlong - Unit of length equal to 40 - Unit of length equal to 40 poles (220 yards).poles (220 yards).

Page 25: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

►Direct Method of Measuring Distance:Direct Method of Measuring Distance:

1. Pacing: 1. Pacing: Where approximate result is Where approximate result is required, distance may be determined by required, distance may be determined by pacing. This method is used for pacing. This method is used for reconnaissance survey, for preparation of reconnaissance survey, for preparation of military plans. Also used for approximate military plans. Also used for approximate checking distance. The method consists of checking distance. The method consists of walking over a line and counting the number walking over a line and counting the number of paces (80cm) the required distance may be of paces (80cm) the required distance may be obtained by multiplying the number of paces obtained by multiplying the number of paces by the average length of pace. by the average length of pace.

Page 26: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

The length of pace varies with the:The length of pace varies with the:

► Individual, age, height and physical Individual, age, height and physical conditioncondition

►The nature of the ground (uphill and The nature of the ground (uphill and down hill)down hill)

►The slope of the country andThe slope of the country and►The speed of pacingThe speed of pacing

Page 27: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

2. Passometer2. Passometer: :

It is a pocket instrument. It It is a pocket instrument. It automatically records the number of automatically records the number of paces. It should be carried vertically, in paces. It should be carried vertically, in waistcoat pocket or suspended from a waistcoat pocket or suspended from a button. The mechanism being operated button. The mechanism being operated by motion and strain of the body.by motion and strain of the body.

Page 28: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

►3. Pedometer:3. Pedometer:

► It is similar to passometer. But it registers the It is similar to passometer. But it registers the distance walked by the persons carrying it. distance walked by the persons carrying it. The distance is read by means of an indicator. The distance is read by means of an indicator. It is fitted with a stud or knob, which when It is fitted with a stud or knob, which when pressed release indicator to zero, it may be pressed release indicator to zero, it may be carried in the same way as the passometer.carried in the same way as the passometer.

Page 29: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

4. Odometer:4. Odometer:It measures the distance approximately. It It measures the distance approximately. It can be attached to the wheel of any vehicle, can be attached to the wheel of any vehicle, such as carriage, cart bicycle, etc. It such as carriage, cart bicycle, etc. It registers the number of revolution of the registers the number of revolution of the wheel. Knowing the circumference of the wheel. Knowing the circumference of the wheel, the distance traversed may be wheel, the distance traversed may be obtained by multiplying the number of obtained by multiplying the number of revolutions. By the circumference of the revolutions. By the circumference of the wheelwheel

Page 30: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

5. Speedometer5. Speedometer: The Speedometer of : The Speedometer of an automobile may be used to measure an automobile may be used to measure distances approximately. It gives better distances approximately. It gives better results than pacing, provided the route is results than pacing, provided the route is smooth.smooth.

Page 31: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

6. Perambulator: 6. Perambulator: It can measure distance It can measure distance rapidly. It consist a single wheel rapidly. It consist a single wheel provided with forks and a handle. It is provided with forks and a handle. It is wheeled along the line, the length of which wheeled along the line, the length of which is desired. The distance traversed is is desired. The distance traversed is automatically registered on the dial. The automatically registered on the dial. The reading approximates on rough ground.reading approximates on rough ground.

Page 32: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

7. Judging distance:7. Judging distance:This is very rough method of determining This is very rough method of determining distance. It is used reconnaissance survey.distance. It is used reconnaissance survey.

8. Time Measurement:8. Time Measurement:Distance is roughly determined by time Distance is roughly determined by time intervals of travel. Knowing the average intervals of travel. Knowing the average time per km for a person at walk or a horse, time per km for a person at walk or a horse, the distance traversed may be easily the distance traversed may be easily obtained.obtained.

Page 33: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Methods of Measuring Methods of Measuring DistanceDistance

9. Chaining: 9. Chaining: Measuring distance with Measuring distance with chain or rope is the most accurate and chain or rope is the most accurate and common method, called as chaining. For common method, called as chaining. For work of ordinary precision a chain is used. work of ordinary precision a chain is used. Where great accuracy is required, a steel Where great accuracy is required, a steel tape is used.tape is used.

Page 34: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Measurement of DistanceMeasurement of Distance

► TapingTaping: applying the known length of a : applying the known length of a graduated tape directly to a line a number of graduated tape directly to a line a number of times.times.

2 Problems exist in Taping:2 Problems exist in Taping:

1.1. Measuring the distance between two existing Measuring the distance between two existing pointspoints

2.2. Laying out a known distance with only the Laying out a known distance with only the starting point in placestarting point in place

Page 35: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Measurement of DistanceMeasurement of Distance6 Steps of Taping6 Steps of Taping

1.1. Lining in – shortest distance between two Lining in – shortest distance between two points is a straight line.points is a straight line.

2.2. Applying tension – rear chain is anchor and Applying tension – rear chain is anchor and head chain applies required tension.head chain applies required tension.

3.3. Plumbing – horizontal distance requires tape Plumbing – horizontal distance requires tape to be horizontal.to be horizontal.

4.4. Marking tape lengths – each application of the Marking tape lengths – each application of the tape requires marking using chaining pins to tape requires marking using chaining pins to obtain total length.obtain total length.

5.5. Reading the tape – the graduated tape must Reading the tape – the graduated tape must be read correctly.be read correctly.

6.6. Recording the distance – the total length must Recording the distance – the total length must be reported and recorded correctly.be reported and recorded correctly.

Page 36: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Types of Chains and TapesTypes of Chains and Tapes

► Before the ability to make steel rods and bands, Before the ability to make steel rods and bands, sticks were cut into lengths of 16.5’ (Rod) and sticks were cut into lengths of 16.5’ (Rod) and they were laid end to end to measure.they were laid end to end to measure.

►Gunter’s ChainGunter’s Chain 66’ long with 100 link w/each link being 7.92 inches 66’ long with 100 link w/each link being 7.92 inches

or 0.66 feet long.or 0.66 feet long. Developed by Edmund Gunter in 1600’s in England Developed by Edmund Gunter in 1600’s in England

and made with individual wires with a loop at each and made with individual wires with a loop at each end connectedend connected

Chain had between 600-800 wearing surfaces which Chain had between 600-800 wearing surfaces which with hard use would wear and cause chain to with hard use would wear and cause chain to elongateelongate

Measurements were recorded in chains and links Measurements were recorded in chains and links 7ch 94.5lk = 7.945 ch = 7.945 X 66’/ch = 524.37’7ch 94.5lk = 7.945 ch = 7.945 X 66’/ch = 524.37’ 1 chain = 4 rods; 80 chains = 1 mile1 chain = 4 rods; 80 chains = 1 mile

Page 37: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Types of Chains and TapesTypes of Chains and Tapes

► Engineer’s ChainEngineer’s Chain Same construction as Gunter’s Chain, but each link Same construction as Gunter’s Chain, but each link

is 1.0’ long and was used for engineering projectsis 1.0’ long and was used for engineering projects

► Surveyor’s and Engineer’s TapesSurveyor’s and Engineer’s Tapes Made of ¼” to 3/8” wide steel tapes in 100’; 200’; Made of ¼” to 3/8” wide steel tapes in 100’; 200’;

300’ lengths300’ lengths

Page 38: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Types of Chains and TapesTypes of Chains and Tapes

► Invar TapesInvar Tapes Made of special nickel steel to reduce length variations Made of special nickel steel to reduce length variations

due to temperature changesdue to temperature changes The tapes are extremely brittle and expensiveThe tapes are extremely brittle and expensive Used most of the time for standard comparison of tapesUsed most of the time for standard comparison of tapes

► Cloth, Fiberglass, and PVC Tapes:Cloth, Fiberglass, and PVC Tapes: Lower accuracy and stored on reels. Used for Lower accuracy and stored on reels. Used for

measurement of 0.1’ accuracy requirementsmeasurement of 0.1’ accuracy requirementsAccessoriesAccessories

1.1. Chaining Pins – set of 11, used to mark the tape lengthsChaining Pins – set of 11, used to mark the tape lengths2.2. Hand Level – used to determine required plumbing heightHand Level – used to determine required plumbing height3.3. Plumb Bob – used to transfer the mark from the tape to Plumb Bob – used to transfer the mark from the tape to

groundground4.4. Tension Handle – used to maintain correct tension on tapeTension Handle – used to maintain correct tension on tape

Page 39: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Taping (Field Process)Taping (Field Process)

1.1. The line to be taped should be marked at both The line to be taped should be marked at both endsends

Keeps measurement on lineKeeps measurement on line Rear chain person should keep the head chain Rear chain person should keep the head chain

person on lineperson on line 1’ of line error/100’ = 0.01’ error in length1’ of line error/100’ = 0.01’ error in length

2.2. Applying TensionApplying Tension Rear chainman is anchor and should hold 100’ Rear chainman is anchor and should hold 100’

mark over pointmark over point► Tension is applied by head chain person – normally 12 to Tension is applied by head chain person – normally 12 to

30 pounds of pull30 pounds of pull► Tapes are standardized at 12 lbs., but greater is utilized to Tapes are standardized at 12 lbs., but greater is utilized to

compensate for sagcompensate for sag

Page 40: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Taping (Field Process)Taping (Field Process)

3.3. PlumbingPlumbing One end of tape is raised to maintain a horizontal One end of tape is raised to maintain a horizontal

measuring plane. measuring plane. ONLYONLY one end is elevated one end is elevated► This allows measurements to be made on uneven groundThis allows measurements to be made on uneven ground► If a high spot exists in center, “break” tape by measuring If a high spot exists in center, “break” tape by measuring

to the top and then move forward to complete the distanceto the top and then move forward to complete the distance

Page 41: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Slope Measurements:Slope Measurements:

►Generally, measurements are made Generally, measurements are made horizontally, but on even, often man-made horizontally, but on even, often man-made slopes the distance can be measured directly slopes the distance can be measured directly on the slope, but the vertical or zenith angle on the slope, but the vertical or zenith angle must be obtained.must be obtained. Horizontal Distance = sin Zenith Angle X Slope Horizontal Distance = sin Zenith Angle X Slope

DistanceDistance Horizontal Distance = cos Vertical Angle X Slope Horizontal Distance = cos Vertical Angle X Slope

DistanceDistance

Page 42: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Taping ErrorTaping Error::

1.1. Instrumental Error – a tape may have different length Instrumental Error – a tape may have different length due to defect in manufacture or repair or as the result due to defect in manufacture or repair or as the result of kinksof kinks

2.2. Natural Error – length of tape varies from normal due Natural Error – length of tape varies from normal due to temperature, wind and weight of tape (sag)to temperature, wind and weight of tape (sag)

3.3. Personal Error – tape person may be careless in setting Personal Error – tape person may be careless in setting pins, reading the tape, or manipulating the equipmentpins, reading the tape, or manipulating the equipment► Instrumental and natural error can be corrected mathematically, Instrumental and natural error can be corrected mathematically,

but personal error can only be corrected by remeasure.but personal error can only be corrected by remeasure.►When a tape is obtained, it should either be standardized or When a tape is obtained, it should either be standardized or

checked against a standard.checked against a standard.► Tapes standardized at National Bureau of Standards in MarylandTapes standardized at National Bureau of Standards in Maryland

► Standardized at 68 degrees F and 12 lbs. tension fully supported.Standardized at 68 degrees F and 12 lbs. tension fully supported.

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Tape Error Correction:Tape Error Correction:

1)1) Measuring between two existing points:Measuring between two existing points:1)1) If a tape is long, the distance will be short, thus any If a tape is long, the distance will be short, thus any

correction must be addedcorrection must be added

2)2) If tape is short, the distance will be long, thus any If tape is short, the distance will be long, thus any correction must be subtractedcorrection must be subtracted

3)3) If you are setting or establishing a point, the above If you are setting or establishing a point, the above rule is reversed.rule is reversed.

Generally can correct for tape length, Generally can correct for tape length, temperature, tension, and sag, but tension temperature, tension, and sag, but tension and sag are negated by increasing tension and sag are negated by increasing tension to approximately 25 – 30 lbs.to approximately 25 – 30 lbs.

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Error in TapingError in Taping::

► Tape Length: Correction per foot = Error in Tape Length: Correction per foot = Error in 100’/100’100’/100’ If tape was assumed to be 100.00’ but when If tape was assumed to be 100.00’ but when

standardized was found to be 100.02’ after distance standardized was found to be 100.02’ after distance measured at 565.75’measured at 565.75’

then: Correction =(100.02-100.00)/100.00 = 0.0002’ then: Correction =(100.02-100.00)/100.00 = 0.0002’ error/fterror/ft

565.75’ X .0002’/’ = 0.11’ correction and based upon 565.75’ X .0002’/’ = 0.11’ correction and based upon rule, must be added, thus true distance = 565.86’rule, must be added, thus true distance = 565.86’

If tape had been 99.98’ then correction would be If tape had been 99.98’ then correction would be subtracted and true distance would be 565.64’subtracted and true distance would be 565.64’

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Error in TapingError in Taping::

► Temperature – Tapes in U.S. are standardized Temperature – Tapes in U.S. are standardized at 68at 68F; the temperature difference above or F; the temperature difference above or below that will change the length of the tapebelow that will change the length of the tape Tapes have a relatively constant coefficient of Tapes have a relatively constant coefficient of

expansion of 0.0000065 per unit length per expansion of 0.0000065 per unit length per FF CT = 0.0000065(Temp (CT = 0.0000065(Temp (F)-68) LengthF)-68) Length Example: Assume a distance was measured when Example: Assume a distance was measured when

temperature was 30°F using a 100’ tape was 872.54’ temperature was 30°F using a 100’ tape was 872.54’ (68 – 30) X 0.00000645 X 872.54’ = 0.21’ error (68 – 30) X 0.00000645 X 872.54’ = 0.21’ error tape is short, thus distance is long, error must tape is short, thus distance is long, error must be subtracted and thus 872.54’ – 0.21’ = 872.33’be subtracted and thus 872.54’ – 0.21’ = 872.33’

(note: temperature difference is absolute difference)(note: temperature difference is absolute difference)

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Surveying Metric ConversionSurveying Metric Conversion

► 1 Survey Foot = 1200 / 3937 meters1 Survey Foot = 1200 / 3937 meters► 1 Meter = 3937 / 1200 Survey Feet1 Meter = 3937 / 1200 Survey Feet

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TransitTransit► Transit is the most universal of Transit is the most universal of

surveying instruments – primary surveying instruments – primary use is for measurement or layout of use is for measurement or layout of horizontal and vertical angles – also horizontal and vertical angles – also used to determine vertical and used to determine vertical and horizontal distance by stadia, horizontal distance by stadia, prolonging straight lines, and low-prolonging straight lines, and low-order leveling.order leveling.

3 Components of the Transit3 Components of the Transit

1.1. Alidade – Upper partAlidade – Upper part

2.2. Horizontal limb – Middle partHorizontal limb – Middle part

3.3. Leveling-head assembly – Lower Leveling-head assembly – Lower partpart

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TransitTransit

►Alidade (upper part)Alidade (upper part) Circular cover plate w/2 level vials and is Circular cover plate w/2 level vials and is

connected to a solid conical shaft called the connected to a solid conical shaft called the inner spindle.inner spindle.

Contains the vernier for the horizontal circleContains the vernier for the horizontal circle Also contains frames that support the Also contains frames that support the

telescope called STANDARDStelescope called STANDARDS Contains the vertical circle and its verniers, Contains the vertical circle and its verniers,

the compass box, the telescope and its level the compass box, the telescope and its level vialvial

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TransitTransit

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TransitTransit

►Horizontal Limb (middle part)Horizontal Limb (middle part) This is rigidly connected to a hollow conical This is rigidly connected to a hollow conical

shaft called the outer spindle (which holds shaft called the outer spindle (which holds the inner spindle)the inner spindle)

Also has the upper clamp, which allows the Also has the upper clamp, which allows the alidade to be clamped tightalidade to be clamped tight

Also contains the horizontal circleAlso contains the horizontal circle

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TransitTransit

► Leveling-Head Assembly (lower part)Leveling-Head Assembly (lower part)1.1. 4 – leveling screws4 – leveling screws

2.2. Bottom plate that screws into tripodBottom plate that screws into tripod

3.3. Shifting device that allows transit to move ¼ to 3/8” Shifting device that allows transit to move ¼ to 3/8”

4.4. ½ ball that allows transit to tilt when being leveled½ ball that allows transit to tilt when being leveled

5.5. The SPIDER – 4-arm piece which holds the outer The SPIDER – 4-arm piece which holds the outer spindlespindle

6.6. Lower clamp – allows rotation of outer spindleLower clamp – allows rotation of outer spindle

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►Telescope: Similar to that of dumpy Telescope: Similar to that of dumpy level, but shorterlevel, but shorter Parts – objective, internal focusing lens, Parts – objective, internal focusing lens,

focusing wheel, X-hairs, & eyepiecefocusing wheel, X-hairs, & eyepiece

► Scales: horizontal plate or circle is usually Scales: horizontal plate or circle is usually graduated into 30’ or 20’ spaces with graduated into 30’ or 20’ spaces with graduations from 0graduations from 0 to 360 to 360 in both directions in both directions Circles are graduated automatically by machine and Circles are graduated automatically by machine and

then scanned to ensure accuracythen scanned to ensure accuracy They are correct to with in 2” of arcThey are correct to with in 2” of arc

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VerniersVerniers

► Least count = Lowest # of reading possible – Least count = Lowest # of reading possible – determines accuracydetermines accuracy

► Least Count = (Value of smallest division on Least Count = (Value of smallest division on scale)/(# of divisions on vernier)scale)/(# of divisions on vernier)

Scale Graduation Vernier Divisions Least Count

30’ 30 1’

20’ 40 30”

15’ 45 20”

10’ 60 10”

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VerniersVerniers

► 3 Types of Verniers3 Types of Verniers1.1. Direct or single vernier – reads only in one direction Direct or single vernier – reads only in one direction

& must be set with graduations ahead of zero& must be set with graduations ahead of zero

2.2. Double vernier – can be read clockwise or Double vernier – can be read clockwise or counterclockwise–only ½ is used at a timecounterclockwise–only ½ is used at a time

3.3. Folded vernier – avoids a ling vernier plate Folded vernier – avoids a ling vernier plate ½ of the graduations are placed on each side of the index ½ of the graduations are placed on each side of the index

markmark Use is not justified because it is likely to cause errorsUse is not justified because it is likely to cause errors

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VerniersVerniers

► The vernier is always read in the same direction The vernier is always read in the same direction from zero as the numbering of the circle, i.e. from zero as the numbering of the circle, i.e. the direction of the increasing anglesthe direction of the increasing angles

► Typical mistakes in reading verniers result fromTypical mistakes in reading verniers result from1.1.Not using magnifying glassNot using magnifying glass

2.2.Reading in the wrong direction from zero, or on the Reading in the wrong direction from zero, or on the wrong side of a double vernierwrong side of a double vernier

3.3.Failing to determine the least count correctlyFailing to determine the least count correctly

4.4.Omitting 10’, 15’, 20’, 30’ when the index is beyond Omitting 10’, 15’, 20’, 30’ when the index is beyond those marksthose marks

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Properties of the TransitProperties of the Transit

1.1. Designed to have proper balance between:Designed to have proper balance between: Magnification and resolution of the telescopeMagnification and resolution of the telescope Least count of the vernier and sensitivity of the plate and Least count of the vernier and sensitivity of the plate and

telescope bubblestelescope bubbles

2.2. Average length of sight of 300’ assumed in designAverage length of sight of 300’ assumed in design3.3. Specifications of typical 1’ gun:Specifications of typical 1’ gun:

Magnification – 18 to 28XMagnification – 18 to 28X Field of view - 1Field of view - 1 to 1 to 130’30’ Minimum focus – 5’ to 7’Minimum focus – 5’ to 7’ X-hairs usually are + with stadia lines above and belowX-hairs usually are + with stadia lines above and below The transit is a repeating instrument because angles are The transit is a repeating instrument because angles are

measured by repetition and the total is added on the platemeasured by repetition and the total is added on the plate► Advantages of this:Advantages of this:

1.1. Better accuracy obtained through averagingBetter accuracy obtained through averaging2.2. Disclosure of errors by comparing values of the single and multiple Disclosure of errors by comparing values of the single and multiple

readingsreadings

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Handling the TransitHandling the Transit

►Hints on handling and setting-up the transitHints on handling and setting-up the transit Pick up transit by leveling head and standardsPick up transit by leveling head and standards When carrying the transit, have telescope locked in When carrying the transit, have telescope locked in

position perpendicular to the leveling head with position perpendicular to the leveling head with objective lens downobjective lens down

When setting-up, keep tripod head level and bring When setting-up, keep tripod head level and bring plumb bob to within ¼” of point to be set over, then plumb bob to within ¼” of point to be set over, then loosen leveling screws enough to enable you to loosen leveling screws enough to enable you to movemove transit on plate, then move transit until it is transit on plate, then move transit until it is over the pointover the point

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C

A

B

Operation of TransitOperation of Transit

► 9 Steps9 Steps1.1. Set up over point B and level it. Loosen both motionsSet up over point B and level it. Loosen both motions

2.2. Set up the plates to read 0Set up the plates to read 0 and tighten the upper and tighten the upper clamp. (Upper and lower plates are locked together)clamp. (Upper and lower plates are locked together)

3.3. Bring Vernier to exactly 0Bring Vernier to exactly 0 using upper tangent screw using upper tangent screw and magnifying glass.and magnifying glass.

4.4. Sight on point A and set vertical X-hair in center of Sight on point A and set vertical X-hair in center of point, by rotating transitpoint, by rotating transit

5.5. Tighten the lower clamp and entire transit is locked inTighten the lower clamp and entire transit is locked in

6.6. Set X-hair exactly on BS point A using the lower Set X-hair exactly on BS point A using the lower tangent screws. At this point the vernier is on 0tangent screws. At this point the vernier is on 0 00’ 00’ and the X-hairs are on BSand the X-hairs are on BS

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Operation of TransitOperation of Transit

7.7. Loosen the upper clamp, turn instrument to right Loosen the upper clamp, turn instrument to right until you are near pt. C. Tighten the upper clampuntil you are near pt. C. Tighten the upper clamp

8.8. Set vertical X-hair exactly on pt. C using the upper Set vertical X-hair exactly on pt. C using the upper tangent screw.tangent screw.

9.9. Read Read on vernier on vernier► If repeating If repeating , loosen lower motion and again BS on A , loosen lower motion and again BS on A

(using only lower motion), and then loosen upper motion (using only lower motion), and then loosen upper motion to allow to allow to accumulate. to accumulate.

► If an instrument is in adjustment, leveled, exactly If an instrument is in adjustment, leveled, exactly centered, and operated by an experienced observer centered, and operated by an experienced observer under suitable conditions, there are only 2 sources for under suitable conditions, there are only 2 sources for error.error.

1.1. Pointing the telescopePointing the telescope

2.2. Reading the platesReading the plates

C

A

B

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Transit Field NotesTransit Field Notes

1d Mean

0-90 (4d)4

90-180 (4d + 360) 4

180-270 (4d + 720) 4

270-360 (4d + 1080) 4

Use longest side for backsite

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TOTAL STATIONS

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TOTAL STATION SET UP

► WHEN TOTAL STATION IS MOVED OR TRANSPORTED, IT MUST BE IN THE CASE!!!!!!!!

1. ESTABLISH TRIPOD OVER THE POINT.2. OPEN THE CASE AND REMOVE TOTAL STATION, PLACING IT ON THE

HEAD OF THE TRIPOD AND ATTACH SECURELY WITH CENTER SCREW.

3. CLOSE THE CASE.4. GRASP TWO TRIPOD LEGS AND LOOK THROUGH THE OPTICAL

PLUMB, ADJUST THE LEGS SO THAT BULLSEYE IS OVER THE POINT (KEEP THE TRIPOD HEAD AS LEVEL AS POSSIBLE).

5. UTILIZING THE TRIPOD LEG ADJUSTMENTS, LEVEL THE TOTAL STATION USING THE FISH-EYE BUBBLE.

6. LOOSEN THE CENTER SCREW TO ADJUST THE TOTAL STATION EXACTLY OVER THE POINT IF NEEDED.

7. COMPLETE LEVELING THE TOTAL STATION USING THE LEVEL VIAL.8. CHECK TO MAKE SURE YOU ARE STILL ON THE POINT.

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TURNING ANGLES WITH TOTAL STATION1. SIGHT ON THE BACKSIGHT UTILIZING THE HORIZONTAL ADJUSTMENT

SCREW.2. ZERO SET THE INSTRUMENT (THIS PROVIDES AN INNITIAL READING OF

0 SECONDS.3. LOOSEN TANGENT SCREW AND ROTATE INSTRUMENT TO FORESIGHT.4. TIGHTEN TANGENT SCREW AND BRING CROSS HAIR EXACT ON TARGET

WITH ADJUSTMENT SCREW.5. READ AND RECORD ANGLE AS DISPLAYED.

TO CLOSE THE HORIZON:1. SIGHT ON FORESIGHT POINT FROM ABOVE AND ZERO SET INSTRUMENT.2. ROTATE TO FORMER BACKSIGHT AND ADJUST INSTRUMENT TO EXACT.3. READ AND RECORD ANGLE AS DISPLAYED.

ANGLE FROM DIRECT AND INDIRECT SHOULD EQUAL 360 DEGREES.

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TOTAL STATION DISTANCE MEASUREMENT

1. POINT THE INSTRUMENT AT A PRISM (WHICH IS VERTICAL OVER THE POINT.

2. PUSH THE MEASURE BUTTON AND RECORD THE DISTANCE.

YOU CAN MEASURE THE HORIZONTAL DISTANCE OR THE SLOPE DISTANCE, IT IS IMPORTANT THAT YOU NOTE WHICH IS BEING COLLECTED.

1. IF YOU ARE MEASURING THE SLOPE DISTANCE, THE ZENITH ANGLE MUST BE RECORDED TO ALLOW THE HORIZONTAL DISTANCE TO BE COMPUTED.

2. IF YOU ARE COLLECTING TOPOGRAPHIC DATA WITH ELEVATIONS, IT IS IMPORTANT THAT THE HEIGHT OF THE INSTRUMENT AND THE HEIGHT OF THE PRISM BE COLLECTED AND RECORDED.THIS CAN ALSO BE SOLVED BY SETTING THE PRISM HEIGHT THE SAME AS THE INSTRUMENT HEIGHT.

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TOTAL STATION RULES

1. NEVER POINT THE INSTRUMENT AT THE SUN, THIS CAN DAMAGE THE COMPONENTS OF THE INSTRUMENT AS WELL AS CAUSE IMMEDIATE BLINDNESS.

2. NEVER MOVE OR TRANSPORT THE TOTAL STATION UNLESS IT IS IN THE CASE PROVIDED.

3. DO NOT ATTEMPT TO ROTATE THE INSTRUMENT UNLESS THE TANGENT SCREW IS LOOSE.

4. AVOID GETTING THE INSTRUMENT WET, IF IT DOES GET WET, WIPE IT DOWN AND ALLOW TO DRY IN A SAFE AREA BEFORE STORAGE.

5. BATTERIES OF THE TOTAL STATION ARE NICAD AND THUS MUST BE CHARGED REGULARLY. AT LEAST ONCE PER MONTH, THE BATTERY SHOULD BE CYCLED.

6. CARE SHOULD BE TAKEN AT ALL TIMES, THESE UNITS ARE EXPENSIVE ($8,000 - $45,000)

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Angles and Determination of Angles and Determination of DirectionDirection

► Angle – difference in direction of 2 linesAngle – difference in direction of 2 lines Another way of explaining is the amount of rotation about a Another way of explaining is the amount of rotation about a

central point central point 3 kinds of Horizontal angles: Exterior (3 kinds of Horizontal angles: Exterior ( to right); Interior; to right); Interior;

DeflectionDeflection To turn an angle you needTo turn an angle you need

► A reference lineA reference line► Direction of turningDirection of turning► Angular distanceAngular distance

Angular UnitsAngular Units► Degrees, minutes, seconds (sexagesimal system)Degrees, minutes, seconds (sexagesimal system)

Circle divided into 360 degreesCircle divided into 360 degrees Each degree divided by 60 minutesEach degree divided by 60 minutes Each minute divided into 60 secondsEach minute divided into 60 seconds

► RadiansRadians 1 radian = 1/21 radian = 1/2 of a circle = 0.1592*360 = 57 of a circle = 0.1592*360 = 5717’44. 8”17’44. 8”

► Grads (Centesimal System) – now called GonGrads (Centesimal System) – now called Gon 1/400 of a circle or 01/400 of a circle or 054’00” (100 gon = 9054’00” (100 gon = 90))

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Angles and Determination of Angles and Determination of DirectionDirection

► Angles turned in field must be accurate: Angles turned in field must be accurate: 3X least 3X least count is max. errorcount is max. error

► Check #1 – Close horizon when turningCheck #1 – Close horizon when turning► If traverse closes: sum of the interior angles should If traverse closes: sum of the interior angles should

equal the sum of equal the sum of (N-2)X180, N = Number of sides(N-2)X180, N = Number of sides

► 3 angles = (3-2) 180 = 1803 angles = (3-2) 180 = 180► 4 angles = (4-2) 180 = 3604 angles = (4-2) 180 = 360► 8 angles = (8-2) 180 = 10808 angles = (8-2) 180 = 1080► 25 angles = (25-2) 180 = 414025 angles = (25-2) 180 = 4140

If an exterior angle exists, subtract it from 360 to obtain the If an exterior angle exists, subtract it from 360 to obtain the interior interior

Angular closure should be checked before leaving the fieldAngular closure should be checked before leaving the field

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Angles and Determination of Angles and Determination of DirectionDirection

► If angular adjustment does not divide out equally:If angular adjustment does not divide out equally:1.1. Do not go to decimal unless instrument reads to decimalDo not go to decimal unless instrument reads to decimal2.2. Observe field notes for angles with poor closure or where Observe field notes for angles with poor closure or where

problems turning angles existed. Apply excess to these problems turning angles existed. Apply excess to these angles evenly.angles evenly.

3.3. If unable to view field notes or no apparent source, generally If unable to view field notes or no apparent source, generally apply excess to angles with shortest sidesapply excess to angles with shortest sides

► Bearings/AzimuthsBearings/Azimuths BearingBearing of a line is the acute horizontal angle between a of a line is the acute horizontal angle between a

reference meridian (North and South) and a linereference meridian (North and South) and a line Azimuth Azimuth of a line is the horizontal angle measured from the of a line is the horizontal angle measured from the

North meridian clockwise to the line North meridian clockwise to the line

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ExampleExample

L

M

N

P

Q

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Angles and Determination of Angles and Determination of DirectionDirection4 Point Comparison

Bearing Azimuth

1. Numeric Value 0-90 0-360

2. Method of Expressing 2 letters & number Number only

3. Direction Clockwise & counterclockwise Clockwise

4. Position of 0 point North and South North

It is always very important to have your It is always very important to have your field sketch properly orientedfield sketch properly oriented

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Angles and Determination of Angles and Determination of DirectionDirection

Rectangular CoordinatesRectangular Coordinates► Totally based on computation of right triangleTotally based on computation of right triangle

North – South Movement = Latitude = D X North – South Movement = Latitude = D X cos Acos A

East – West Movement = Departure = D X East – West Movement = Departure = D X sin Asin A

► Latitude running North are +, South are –Latitude running North are +, South are –► Departure running East are +, West are –Departure running East are +, West are –

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Angles and Determination of Angles and Determination of DirectionDirection

► Basic ProcedureBasic Procedure1.1. Determine Latitude and DepartureDetermine Latitude and Departure

2.2. Sum Lat. and Departure to calc. closureSum Lat. and Departure to calc. closure

3.3. Obtain balanced Lat. and Dept. (Compass Rule)Obtain balanced Lat. and Dept. (Compass Rule)

4.4. Determine coordinatesDetermine coordinates

5.5. Once rectangular coordinates are known on point, Once rectangular coordinates are known on point, their exact location is known with respect to all their exact location is known with respect to all other points in the networkother points in the network

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ExampleExample

F

A

B

C

D

99-39-30 421.97’

47-28-00

483.52’

392.2

8’

188-2

7-3

0

236-27-00

886.04’

26-1

6-30

452.

66’

279.33’

320-42-00

E

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Angles and Determination of Angles and Determination of DirectionDirection

► Balancing MethodsBalancing Methods1.1. Compass Rule: (Bowditch) Used when accuracy of Compass Rule: (Bowditch) Used when accuracy of and length and length

measurement is equalmeasurement is equal► (Error Lat./Perimeter length) X Distance = Latitude Correction(Error Lat./Perimeter length) X Distance = Latitude Correction► (Error Dept./Perimeter length) X Distance = Departure Correction(Error Dept./Perimeter length) X Distance = Departure Correction

2.2. Transit Rule: Used if angles are more accurate than distances Transit Rule: Used if angles are more accurate than distances (more accurate direction)(more accurate direction)► Correction Latitude (Side) = (Lat. Side/Sum all Lat.) X Lat. errorCorrection Latitude (Side) = (Lat. Side/Sum all Lat.) X Lat. error► Correction Departure (Side) = (Dept. Side/Sum all Dept.) X Dept. Correction Departure (Side) = (Dept. Side/Sum all Dept.) X Dept.

errorerror

3.3. Crandall Method: Used when larger random error exists in linear Crandall Method: Used when larger random error exists in linear measurements that angular. Directional adjustments from measurements that angular. Directional adjustments from balancing are held fixed and distances are balanced by a balancing are held fixed and distances are balanced by a weighted least squares procedureweighted least squares procedure

4.4. Least Squares: Based on the theory of probability. Angular and Least Squares: Based on the theory of probability. Angular and linear adjustments are made simultaneously. Hand methods are linear adjustments are made simultaneously. Hand methods are long and complex long and complex not often done. Computer adjustment not often done. Computer adjustment through existing software make it feasible, which is why it is through existing software make it feasible, which is why it is often used todayoften used today

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Area, Inverse, IntersectionArea, Inverse, Intersection

► Once rectangular coordinates are established Once rectangular coordinates are established on all points, the relationship to all other on all points, the relationship to all other points is known. You can:points is known. You can:

1.1. Determine area of all or any portionDetermine area of all or any portion

2.2. Determine length and direction between any 2 Determine length and direction between any 2 pointspoints

3.3. Locate new points by intersectionLocate new points by intersection

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Area, Inverse, IntersectionArea, Inverse, Intersection► Area: Method is area by cross multiplicationArea: Method is area by cross multiplicationUsing example from traverse lecture:Using example from traverse lecture:

NA X NA X EB + NB X EC + NC X ED + ND X EE + NE X EF + NF X EA = Sum NEB + NB X EC + NC X ED + ND X EE + NE X EF + NF X EA = Sum N

EA X NB + EB X NC + EC X ND + ED X NE + EE X NF + EF X NA = Sum EEA X NB + EB X NC + EC X ND + ED X NE + EE X NF + EF X NA = Sum E

Difference in Sums/2 Difference in Sums/2 = Square feet= Square feet

Square feet/43560 = AcresSquare feet/43560 = AcresA 10000.0000 5000.0000

B 10326.7981 5356.3614

C 9938.7277 5298.7122

D 9448.9156 4560.3990

E 9854.7405 4760.8417

F 10070.8565 4583.9559

A 10000.0000 5000.0000

Sum N = 294,119,678.8Sum E = 293,663,353.6

456,325.2 / 2 = 228,162.6 ft2 = 5.24 Ac

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Area, Inverse, IntersectionArea, Inverse, Intersection

Example: Determine Area of A, D, E, F, AExample: Determine Area of A, D, E, F, A

N = 186,116,759.8E = 185,971,439.3

145,320.5 / 2 = 72,660.25 ft2 = 1.67 Ac

A 10000.0000 5000.0000

D 9448.9156 4560.3990

E 9854.7405 4760.8417

F 10070.8565 4583.9559

A 10000.0000 5000.0000

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Area, Inverse, IntersectionArea, Inverse, Intersection► Inverse: With known coordinates of any two points on a Inverse: With known coordinates of any two points on a

system, you find the distance and direction between the system, you find the distance and direction between the twotwo

CC 9938.72779938.7277 5298.71225298.7122DD 9448.91569448.9156 4560.39904560.3990 489.8121489.8121 738.3132 738.3132

► To find the Inverse between 2 PointsTo find the Inverse between 2 Points1.1. Find difference in N & E of coordinatesFind difference in N & E of coordinates2.2. PlotPlot

► Use point you are going from 1stUse point you are going from 1st► Plot longest side 1stPlot longest side 1st

3.3. Determine length using Pythagorean (aDetermine length using Pythagorean (a22 + b + b22 = c = c22) ) 4.4. Determine reference directionDetermine reference direction5.5. Determine local Determine local using tan A = a/b using tan A = a/b 6.6. Determine line directionDetermine line direction

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Area, Inverse, IntersectionArea, Inverse, Intersection

► Example: Determine direction and distance D-AExample: Determine direction and distance D-A

D 9448.9156 4560.3990A 10000.0000 5000.0000

551.0844 439.6010

Page 86: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Area, Inverse, IntersectionArea, Inverse, Intersection

► Intersection: Determination of unknown point Intersection: Determination of unknown point location with directions from two points knownlocation with directions from two points known

1.1. Determine difference in coordinatesDetermine difference in coordinates

2.2. Plot points and line projectionsPlot points and line projections

3.3. Set up dual formulas (as Latitude and Departure)Set up dual formulas (as Latitude and Departure)

4.4. Solve for lengthSolve for length

5.5. Compute coordinate as sideshotCompute coordinate as sideshot

C 9938.7277 5298.7122D 9448.9156 4560.3990

489.8121 738.3132

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Area, Inverse, IntersectionArea, Inverse, Intersection

► Example: What are the coordinates of the point Example: What are the coordinates of the point of intersection of line C-F and D-A. of intersection of line C-F and D-A.

Azimuth D-A = 38Azimuth D-A = 3834’46”. 34’46”.

Coordinates of D: N = 9448.9156, E = Coordinates of D: N = 9448.9156, E = 4560.39904560.3990

C 9938.7277 5298.7122F 10070.8565 4583.9559

132.1288 714.7563

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Horizontal and Vertical CurvesHorizontal and Vertical Curves

► Horizontal curves are the basis for most Right of Ways:Horizontal curves are the basis for most Right of Ways: Go through formulasGo through formulas Angle at PC and PT are always 90Angle at PC and PT are always 90 Given any 2 elements T, L, C, R, D; the remainder can be Given any 2 elements T, L, C, R, D; the remainder can be

completedcompleted

Example: Horizontal curve, PC STA 201+00Example: Horizontal curve, PC STA 201+00 D = 36D = 3615’00”15’00” R = 1200.00’R = 1200.00’ T =T = L = L = C =C = Seg = Seg = PI STA = PI STA = PT STA = PT STA =

Page 89: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Horizontal and Vertical CurvesHorizontal and Vertical Curves

► Vertical Curves – Two major methods used to Vertical Curves – Two major methods used to calculate vertical curves: Tangent offset and Equation calculate vertical curves: Tangent offset and Equation of Parabolaof Parabola

Information neededInformation needed::1.1. Grade or slope on each side of curveGrade or slope on each side of curve

2.2. Elevation and station of PVIElevation and station of PVI

3.3. Curve length (Horizontal distance PVC – PVT)Curve length (Horizontal distance PVC – PVT)

Page 90: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Horizontal and Vertical CurvesHorizontal and Vertical Curves

Tangent Offset MethodTangent Offset Method► Procedure:Procedure:

1.1. Compute the elevation of the PVC and PVTCompute the elevation of the PVC and PVT

2.2. Compute the elevation of Chord midpointCompute the elevation of Chord midpoint

3.3. Compute offset to curve at midpointCompute offset to curve at midpoint

4.4. Determine total number of stations coveredDetermine total number of stations covered

5.5. Determine tangent elevations at stationsDetermine tangent elevations at stations

6.6. Compute curve offset at stationsCompute curve offset at stations

7.7. Combine data and determine vertical curve Combine data and determine vertical curve elevationselevations

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Horizontal and Vertical CurvesHorizontal and Vertical Curves

Equation of Parabola MethodEquation of Parabola Method► EquationEquation: r = g2 - g1 / L : r = g2 - g1 / L

gg11 = initial grade = initial grade r = change in grade/sta.r = change in grade/sta. gg22 = final grade = final grade L = length of curve in stationsL = length of curve in stations

► ProcedureProcedure::1.1. Compute PVC and PVT elevationsCompute PVC and PVT elevations2.2. Calculate total change in grade/stationCalculate total change in grade/station3.3. Insert data to chart and compute final curve elevationsInsert data to chart and compute final curve elevations

To find the elevation at the high point or low point, To find the elevation at the high point or low point, find the station at which it fall and include that find the station at which it fall and include that station in the elevation computationsstation in the elevation computations

The equation gives the distance from the PVC in stationsThe equation gives the distance from the PVC in stations

1pt

-gx =

r

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LevelingLeveling

► Leveling is the determination of the elevation of a Leveling is the determination of the elevation of a point or difference between points referenced to some point or difference between points referenced to some datumdatum

Terms:Terms:1.1. DatumDatum – any level surface to which elevations are referenced – any level surface to which elevations are referenced2.2. Mean Sea LevelMean Sea Level (MSL) – the average height of the surface of (MSL) – the average height of the surface of

the sea for all stages of the tide over a 19 year period at 26 the sea for all stages of the tide over a 19 year period at 26 tide stations along Pacific, Atlantic and Gulftide stations along Pacific, Atlantic and Gulf

3.3. National Geodetic Vertical DatumNational Geodetic Vertical Datum – nationwide reference – nationwide reference surface for elevations throughout the U.S. – made available by surface for elevations throughout the U.S. – made available by National Geodetic Survey (NGS), based on 1929 adjustment.National Geodetic Survey (NGS), based on 1929 adjustment.

4.4. BenchmarkBenchmark – relatively permanent object bearing a marked – relatively permanent object bearing a marked point whose elevation above or below an adopted datum.point whose elevation above or below an adopted datum.

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LevelingLeveling

►Most often Mean Sea Level is used Most often Mean Sea Level is used MSL varies along the coastsMSL varies along the coasts Pacific is almost 2’ higher than Atlantic and GulfPacific is almost 2’ higher than Atlantic and Gulf

► U.S. System: National Geodetic Vertical Datum U.S. System: National Geodetic Vertical Datum of 1929of 1929 Has been used as reference for extensive network of Has been used as reference for extensive network of

BM’sBM’s BM’s are periodically adjusted as to elevationBM’s are periodically adjusted as to elevation

►Best to check with USGS or NGS for current elevation of a Best to check with USGS or NGS for current elevation of a BM and also best to check between two known BM’s to verify BM and also best to check between two known BM’s to verify

elevation difference.elevation difference.

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LevelingLeveling► The level surface parallels the curvature of the earth The level surface parallels the curvature of the earth a a

level line is a curved line, normal (level line is a curved line, normal () at all points to ) at all points to plumblineplumbline Line of sight is only normal at point of instrumentLine of sight is only normal at point of instrument A line with a sight distance of 1 mile using the earth’s radius as A line with a sight distance of 1 mile using the earth’s radius as

3959 mile, curvature change is 0.667 feet.3959 mile, curvature change is 0.667 feet.

Refraction of line of sight of level is downward by a small amountRefraction of line of sight of level is downward by a small amount The combined curvature & refraction amounts for short distances The combined curvature & refraction amounts for short distances

(normal sight dist. for levels) are:(normal sight dist. for levels) are: 100’ = 0.0002’100’ = 0.0002’ 200’ = 0.0008’200’ = 0.0008’ 300’ = 0.0019’300’ = 0.0019’ 500’ = 0.0052500’ = 0.0052

Value is small for most instances can be neglected

Page 95: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

LevelingLeveling

► Most common leveling instrument today is the Most common leveling instrument today is the Automatic or Self-leveling level – has an internal Automatic or Self-leveling level – has an internal compensator that automatically provides a compensator that automatically provides a horizontal line of sight and maintains this through horizontal line of sight and maintains this through gravity (prism hanging on pendulum)gravity (prism hanging on pendulum)

► Differential Leveling: (Spirit Leveling) Most common Differential Leveling: (Spirit Leveling) Most common type todaytype today

Determine the difference in elevation using a horizontal line Determine the difference in elevation using a horizontal line of sight and readings on graduated rodof sight and readings on graduated rod

Circuit must be closed on BM of origin or on BM of equal Circuit must be closed on BM of origin or on BM of equal accuracyaccuracy

Process:Process:1.1. Reading on point of known elevation (BS)Reading on point of known elevation (BS)2.2. BS reading + BM elevation = HIBS reading + BM elevation = HI3.3. Reading on point of unknown elevation (FS)Reading on point of unknown elevation (FS)4.4. HI – FS = elevation of new pointHI – FS = elevation of new point

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LevelingLeveling

► Systematic Error in LevelingSystematic Error in Leveling1.1. Inclination of line of sight due to curvature of earth and Inclination of line of sight due to curvature of earth and

refraction – generally very minimal due to short sightsrefraction – generally very minimal due to short sights2.2. Inclination due to maladjustment of instrumentInclination due to maladjustment of instrument

Both can be alleviated by equalizing length of BS and FS legsBoth can be alleviated by equalizing length of BS and FS legs

3.3. Changes in scale of rod due to temperatureChanges in scale of rod due to temperature Usually ignored except in very precise workUsually ignored except in very precise work Would use same process as tape correctionWould use same process as tape correction

4.4. Rod not held plumbRod not held plumb Minimized by carefully plumbing the rod or more commonly Minimized by carefully plumbing the rod or more commonly

known as “Rocking the Rod” and taking the lowest readingknown as “Rocking the Rod” and taking the lowest reading

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LevelingLeveling

► Peg TestPeg Test1.1. Set 2 marks at 300’ apart, also mark center point in a Set 2 marks at 300’ apart, also mark center point in a

relatively flat arearelatively flat area2.2. Set level at midpoint and take readings at each endSet level at midpoint and take readings at each end3.3. Determine difference in readings (difference in Determine difference in readings (difference in

elevation)elevation)4.4. Move level to one end and setup so that level is just in Move level to one end and setup so that level is just in

front of rod on pointfront of rod on point5.5. Read rod by looking backward through scope (X-hair Read rod by looking backward through scope (X-hair

not visible), hold pencil on rod to determine readingnot visible), hold pencil on rod to determine reading6.6. Read rod at other end in normal mannerRead rod at other end in normal manner7.7. Difference in readings should equal #3Difference in readings should equal #38.8. If values are not equal, there is errorIf values are not equal, there is error

Most instruments have adjustment screwsMost instruments have adjustment screws Adjust and repeat test as a checkAdjust and repeat test as a check

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Seven Basic Rules of Seven Basic Rules of Differential LevelingDifferential Leveling

1.1. Balance length of BS and FS (300’ max)Balance length of BS and FS (300’ max)

2.2. Make sure gun is level and pendulum freeMake sure gun is level and pendulum free

3.3. Turn through all BM’sTurn through all BM’s

4.4. Give complete description of BM’s and TBM’sGive complete description of BM’s and TBM’s

5.5. Have rod rockedHave rod rocked

6.6. Make sure turning points are solidMake sure turning points are solid

7.7. Close all circuits on BM of same degree of Close all circuits on BM of same degree of accuracyaccuracy

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Other Random ErrorsOther Random Errors

1.1. Incorrect rod reading – most common viewing Incorrect rod reading – most common viewing foot number above and recording itfoot number above and recording it

2.2. Parallax – having the X-hair not properly Parallax – having the X-hair not properly focusedfocused

3.3. Heat Waves – limit shot lengthsHeat Waves – limit shot lengths

Page 100: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Field NotesField Notes

STASTA BSBS HIHI FSFS ELEVELEV

►Sum BS – Sum FS = Difference of Sum BS – Sum FS = Difference of ElevationElevation

Page 101: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Closure ErrorClosure Error

►Difference in measured elevation and know Difference in measured elevation and know elevationelevation

► Correction factor = closure / # turnsCorrection factor = closure / # turnsError = 0.09’Error = 0.09’

Turns = 12 Turns = 12 Correction = 0.0075’ / turn Correction = 0.0075’ / turn

► If TBM’s set, break circuit into sectionsIf TBM’s set, break circuit into sections► Figure correction factor the sameFigure correction factor the same► Figure correction by taking CF X # turns in Figure correction by taking CF X # turns in

sectionsection

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Precise LevelingPrecise Leveling

► Precise Leveling – Accuracy obtained by quality of Precise Leveling – Accuracy obtained by quality of instruments and care taken in the fieldinstruments and care taken in the field

► High quality automatic levels are utilizedHigh quality automatic levels are utilized► Level rods are equipped with rod level, rod shoe (to allow Level rods are equipped with rod level, rod shoe (to allow

better setting on BM’s); scale (on rod) is made of invar better setting on BM’s); scale (on rod) is made of invar steel (not affected by temp – generally called Invar Rod)steel (not affected by temp – generally called Invar Rod)

► Reading either taken by optical micrometer or a process Reading either taken by optical micrometer or a process called 3-wire leveling is used (all 3 wire are read and called 3-wire leveling is used (all 3 wire are read and averaged)averaged) Optical micrometer: line of sight deflected by turning micrometer Optical micrometer: line of sight deflected by turning micrometer

screw to read subdivision on rod.screw to read subdivision on rod.► Rod division is read as normal & then fractional reading taken from Rod division is read as normal & then fractional reading taken from

micrometer screw, thus on normal rod readings to 0.0001’ are micrometer screw, thus on normal rod readings to 0.0001’ are possiblepossible

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Topographic SurveyingTopographic Surveying

► Topographic surveying is the process of Topographic surveying is the process of determining the positions, on the earth’s determining the positions, on the earth’s surface, of the natural, and artificial features of surface, of the natural, and artificial features of a given locality and of determining the a given locality and of determining the configuration of the terrain.configuration of the terrain. Planimetry – location of featuresPlanimetry – location of features Topography – configuration of the groundTopography – configuration of the ground

►Both produce a topographic map which shows the true Both produce a topographic map which shows the true distance between objects & their elevations above a given distance between objects & their elevations above a given datumdatum

►Topos can be done by field methods, or by photogrammetric Topos can be done by field methods, or by photogrammetric methods. (Photo also requires some field work)methods. (Photo also requires some field work)

►Topo map is 1Topo map is 1stst step in a construction project step in a construction project

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Topographic SurveyingTopographic Surveying

► Scale and accuracy: Both depend on what used forScale and accuracy: Both depend on what used for► Method of Representing:Method of Representing:

Most common is Most common is Contour LineContour Line – Imaginary line on surface – Imaginary line on surface of the earth passing through points that have equal of the earth passing through points that have equal elevationelevation

Contour IntervalContour Interval – Vertical distance between lines – Vertical distance between lines» Topo map with contour lines shows elevation of points on ground Topo map with contour lines shows elevation of points on ground

& shapes of topographic features (hills, etc.)& shapes of topographic features (hills, etc.)►USGS Topo – 10’ or 20’ contour intercalUSGS Topo – 10’ or 20’ contour intercal►Subdivision – 2’ or 4’Subdivision – 2’ or 4’

Index Contour – every 5Index Contour – every 5thth contour drawn heavier on maps contour drawn heavier on maps Slopes & X-sections can be obtained from contoursSlopes & X-sections can be obtained from contours

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Topographic SurveyingTopographic Surveying

Interpolating – can find elevation of any point or find Interpolating – can find elevation of any point or find contour line with known elevation of pointcontour line with known elevation of point

Contour lines that close represent either a hill or Contour lines that close represent either a hill or depression and can be represented as:depression and can be represented as:

►Marks are called hatchures (used most in depressions)Marks are called hatchures (used most in depressions)

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Characteristics of ContoursCharacteristics of Contours

1.1. Each contour must close upon itself with within Each contour must close upon itself with within a map or outside its borders – a contour line a map or outside its borders – a contour line cannot end on a map except at the edgecannot end on a map except at the edge

2.2. Contours do not cross or meet except in caves, Contours do not cross or meet except in caves, cliffs & vertical walls where they can meetcliffs & vertical walls where they can meet

3.3. Contour lines crossing streams form V’s Contour lines crossing streams form V’s pointing upstreampointing upstream

4.4. Contour lines crossing a ridge form U’s Contour lines crossing a ridge form U’s pointing down the ridgepointing down the ridge

5.5. Contour lines tend to parallel streamsContour lines tend to parallel streams

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Characteristics of ContoursCharacteristics of Contours

6.6. Contour lines are uniformly spaced on uniform Contour lines are uniformly spaced on uniform slopesslopes

7.7. Horizontal spacing between contour lines Horizontal spacing between contour lines indicated steepness of slope on groundindicated steepness of slope on ground

8.8. Contours are generally perpendicular to Contours are generally perpendicular to direction of maximum slopedirection of maximum slope

9.9. Contours can never branch into 2 contours of Contours can never branch into 2 contours of the same elevationthe same elevation

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Field Methods of ToposField Methods of Topos

Factors That Influence MethodFactors That Influence Method

1.1. Scale of mapScale of map

2.2. Contour intervalContour interval

3.3. Type of terrainType of terrain

4.4. Nature of projectNature of project

5.5. Equipment availableEquipment available

6.6. Required accuracyRequired accuracy

7.7. Existing controlExisting control

8.8. Extent of area to be mappedExtent of area to be mapped

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Field Methods of ToposField Methods of Topos

Methods:Methods:

1.1. Cross section – railroad of highwayCross section – railroad of highway

2.2. Trace contour – drainage or impoundmentsTrace contour – drainage or impoundments

3.3. Grid – small areasGrid – small areas

4.4. Controlling point – large area, plane tableControlling point – large area, plane table

5.5. Theodolite & EDM - radialTheodolite & EDM - radial

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Field Methods of ToposField Methods of Topos

Cross Section Method (Plus Offset):Cross Section Method (Plus Offset):

Equipment used: Transit, tape, and levelEquipment used: Transit, tape, and level

1.1. Establish horizontal control – traverse between Establish horizontal control – traverse between control points – stakes set at cross section control points – stakes set at cross section intervalsintervals

2.2. Run profile of traverse lineRun profile of traverse line

3.3. Take cross sectionTake cross section

4.4. Locate planimetric features from traverse lineLocate planimetric features from traverse line

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Field Methods of ToposField Methods of Topos

Trace Contour:Trace Contour:

1.1. Contour is by traverseContour is by traverse

2.2. Establish elevation of each stationEstablish elevation of each station

3.3. Contour elevation established and is then Contour elevation established and is then followed by rodpersonfollowed by rodperson

4.4. Contour elevation is marked, then tied to Contour elevation is marked, then tied to traverse line by plus-offsettraverse line by plus-offset Most accurate and expensive workMost accurate and expensive work Elevation of reservoir water lineElevation of reservoir water line 2 transit use2 transit use

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Field Methods of ToposField Methods of Topos

Grid Method:Grid Method:

1.1. Establish baselinesEstablish baselines

2.2. Estimate grid of uniform size – smaller grid = Estimate grid of uniform size – smaller grid = more accuratemore accurate

3.3. Number gridNumber grid

4.4. Shoot elevation at each pointShoot elevation at each point

5.5. Tie existing objects to grid pointsTie existing objects to grid points

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Field Methods of ToposField Methods of Topos

Controlling Point Method: (old and sketched in Controlling Point Method: (old and sketched in field)field)

1.1. Determine position & elevation of pre-selected Determine position & elevation of pre-selected control pointscontrol points

2.2. Depends greatly on experience & judgment of Depends greatly on experience & judgment of people doing workpeople doing work

3.3. Required traverse of area (CP’s)Required traverse of area (CP’s)

4.4. Locations are made & elevations obtained Locations are made & elevations obtained along control points – then intermittent topo along control points – then intermittent topo sketched insketched in

Page 114: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Field Methods of ToposField Methods of Topos

Theodolite & EDM (Radial)Theodolite & EDM (Radial) Replaces tacheometry (stadia)Replaces tacheometry (stadia)

1.1. Establish control points (horizontal and Establish control points (horizontal and elevation)elevation)

2.2. Shoot locations and turn vertical anglesShoot locations and turn vertical angles

3.3. Used for large areasUsed for large areas

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Field Methods of ToposField Methods of Topos

Common mistakes in topo surveys:Common mistakes in topo surveys:

1.1. Improper selection of contour intervalImproper selection of contour interval

2.2. Unsatisfactory equipment or field method for Unsatisfactory equipment or field method for the particular survey and terrain conditionsthe particular survey and terrain conditions

3.3. Insufficient horizontal and vertical control of Insufficient horizontal and vertical control of suitable precisionsuitable precision

4.4. Omission of some topographic detailsOmission of some topographic details

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Mine SurveyingMine Surveying

► Points are on roof of minePoints are on roof of mine

Reasons neededReasons needed1.1. Location in respect to boundariesLocation in respect to boundaries

2.2. Location in respect to other shaftsLocation in respect to other shafts

3.3. Accurate maps (above and below ground)Accurate maps (above and below ground)

4.4. QuantitiesQuantities

Equipment and TermsEquipment and Terms► Spad – Beams that you hold plumb bob fromSpad – Beams that you hold plumb bob from► Bracket – Mounting instrument from timber supportsBracket – Mounting instrument from timber supports► Trivet – Tripod that’s about 1’ tallTrivet – Tripod that’s about 1’ tall► Gyroscope – Locate northGyroscope – Locate north► Laser vertical collimator – located point at top of vertical shaft Laser vertical collimator – located point at top of vertical shaft

platformplatform► Plumb shaft – Using piano wire then wiggle in at bottomPlumb shaft – Using piano wire then wiggle in at bottom

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Global Positioning Systems Global Positioning Systems (GPS)(GPS)

► Developed in early 1980’ s (Dept. of Defense)Developed in early 1980’ s (Dept. of Defense)► Made up of 26 satellites (24 functioning & 2 spares)Made up of 26 satellites (24 functioning & 2 spares)► Each satellite is 20,000 km high (off Earth’s surface)Each satellite is 20,000 km high (off Earth’s surface)► Each satellite is in a fixed positionEach satellite is in a fixed position► Minimum of 3 satellites needed, but 4-5 preferredMinimum of 3 satellites needed, but 4-5 preferred► Need satellites at least 15° above horizonNeed satellites at least 15° above horizon► Locate positions on Earth by distance-distance Locate positions on Earth by distance-distance

intersectionintersection► Need 2-3 receivers ($80-$100K per system)Need 2-3 receivers ($80-$100K per system)► Most accurate with double occupancy (no other checks)Most accurate with double occupancy (no other checks)► Differential GPS – one receiver on known point, other Differential GPS – one receiver on known point, other

receiver on unknownsreceiver on unknowns

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Global Positioning Systems Global Positioning Systems (GPS)(GPS)

Biggest advantageBiggest advantage►Distance and direction in-between 2 points Distance and direction in-between 2 points

without being seenwithout being seen

Downfalls/Limitations of GPSDownfalls/Limitations of GPS►Multipath – bouncing off of walls of buildingsMultipath – bouncing off of walls of buildings► Blocked signals – clouds, trees, etc.Blocked signals – clouds, trees, etc.► Sunspot – defraction from atmosphereSunspot – defraction from atmosphere►DOP (Delusion of Position) – bad satellite DOP (Delusion of Position) – bad satellite

positionposition► Set up error – not set up exactly over point Set up error – not set up exactly over point

(human error – most common)(human error – most common)

Page 119: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Global Positioning Systems Global Positioning Systems (GPS)(GPS)

MethodsMethods► Static – observation time is at least an hourStatic – observation time is at least an hour

Ideally set points in triangular fashionIdeally set points in triangular fashion Accuracy – 1/10 millionAccuracy – 1/10 million

► RTK (Real Time Kinematic) – stand for 30-60 RTK (Real Time Kinematic) – stand for 30-60 seconds minimumseconds minimum Base receivers transmission, does corrections, sends Base receivers transmission, does corrections, sends

corrections to receiverscorrections to receivers Limitations – limitation of transmitter signalLimitations – limitation of transmitter signal

Page 120: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Geographic Information Geographic Information Systems (GIS)Systems (GIS)

►GIS are computer programs that allow users to GIS are computer programs that allow users to store, retrieve, manipulate, analyze and display store, retrieve, manipulate, analyze and display spatialspatial data data

► Spatial Data (Geographic data) – any data that Spatial Data (Geographic data) – any data that represents information about the Earthrepresents information about the Earth

GIS componentsGIS components Recent definitions of GIS suggest that is consists of:Recent definitions of GIS suggest that is consists of:

1.1.Hardware (computer and operating system)Hardware (computer and operating system)

2.2.SoftwareSoftware

3.3.DataData

4.4.Human Operators and Institutional InfrastructureHuman Operators and Institutional Infrastructure

Geographic/Spatial

Non-Geographic/Aspatial/Attribute

Page 121: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

GIS Data StructuresGIS Data Structures► Vector – Made up of points, lines, and polygonsVector – Made up of points, lines, and polygons

Page 122: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

GIS Data StructuresGIS Data Structures

► Raster (Grids) – Made up of pixels of computer Raster (Grids) – Made up of pixels of computer screenscreen

Page 123: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

GIS Data StructuresGIS Data Structures

►DEM (Digital Elevation Model) – Digital terrain DEM (Digital Elevation Model) – Digital terrain representation technique, where elevation representation technique, where elevation values are stored in raster cellsvalues are stored in raster cells

Page 124: SURVEYING SURVEYING Introduction. Introduction to Surveying ► Definition: Surveying is the science and art of determining the relative positions of points.

Future of SurveyingFuture of Surveying

►Major advances in futureMajor advances in future Remote Sensing (Government and Military)Remote Sensing (Government and Military) Arial PhotographsArial Photographs

►Design ProfessionsDesign Professions Every 10 years, must justify to Legislature that need Every 10 years, must justify to Legislature that need

for our license existsfor our license exists Surveyor have ULTIMATE liabilitySurveyor have ULTIMATE liability Standards → Laws Standards → Laws Continuing Education – Enough points every 2 yearsContinuing Education – Enough points every 2 years


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