REMOTE SENSING AND GIS

Presented by,M.Uma Maheshwari

II M.Sc Botany

Remote sensing

Science and art of obtaining information about an area, object or phenomenon through the analysis of physical data acquired from a distance by a device that is not in direct contact

Definition

1858 Balloonist G.Tournachon made photographs of Paris from his balloon.

Systematic aerial photography developed for military and reconnaissance purposes beginning in World War I and reaching a climax during the Cold War .

Artificial satellites in the latter half of the 20th century

History

Data acquisitionEnergy sourcePropagation of energyAir borne/soil borne sensorsPresentation of sensor data in pictoral or digital form

Data analysis Collection of ground data Interpretation of pictoral data Interpretation of digital data Preparation of maps

Basic concepts

Photographic Non photographic

Sensors used in RS system

Record the reflected solar energy from earth surface

Camera mounted on the aircraft On development and printing aerial

photographs are produced

Photographic sensors

Also called Multi Spectral Scanner (MSS) Record wide spectral range Operated from aircrafts and satellites Indispensible for satellite borne RS system It scans the ground, line by line

perpendicular to the direction of satellite or air craft

The scanning rate in adjusted

Non photographic sensors

Along lines, MSS view only a small area of the ground at a particular instant of time

Called as Instaneous Field Of View (IFOB) The area on ground is called Ground

Resolution Element (GRE) or pixel

Terrestrial ecology Aquatic ecology Animal ecology Ecological damage

Application

By using FCC existing forest can be studied Study area can be mapped and classified

into various canopy classes Any decrease in forest can be easily

determined Forest map is essential for planning of

sampling sites Evaluation of remote sensing using aerial

photograph in a scale of 1:15000 provide multi level information

Terrestrial ecology

Prohibitive cost Non availability of recent and sequential

photographs Restricted nature Problems related to procurement and scale

distortion

Limitations of RS in forest inventories

AP and FCC can be utilized to locate and determine sites from water samples for planktonic studies

FCC can be used for Determining different natural basins Selection of water sampling sites for determining

various chemical quality Level of pollution of surface water

Aquatic ecology

Location of an animal for plotting movements and calculating home range

To assist in location of an animal for direct observation

To record data like EEG, ECG, respiration rate and internal or surface body temperature

Animal ecology

Environmental impact assessment Offshore fishing Crop inventory Crop yielding forecasting

Other applications in ecology

Monitor ecological threats and long term effects to the earth’s natural surface and areas relevant to human activities

Much damage is imposed on vegetation such as areas affected by forest fires and grassland burns

Very easy to see the destruction deposits with volcanic eruptions and sand storms

Oil spills – another catastrophe Monitoring any changes that threats the lives of

endangered animal or plant life

Ecological damage

GIS-Geographic Information System

GIS is a system for managing spatial data and associated attributes

Performs 5 tasks Input Manipulation Management Query and analysis Visualization

Definition

Relating information from different sources Data representation Data capture Data manipulation Projections, coordinate systems and

registration Spatial analysis Graphic display techniques

Techniques used in GIS

Two components Graphical data about geographical features Tabular data about features in the geography

Working patterns of GIS

Variety of GIS software is available Important functional capabilities include

Data capture Data storage Data management Data retrieval Data analysis Data display

Selecting a GIS

Must have a spatial component All information are geo – referenced Geocoding- two methods

Scanning Digitizing

Involves in identifying the objects, location on earth surface and their spatial relationships

Data capture

Possible to link or integrate information through various means

Agricultural records can indicate how much pesticide has been applied to a parcel of land

By locating the parcels and intersecting them with streams can predict amount nutrient run off

Data integration

Tremendous amount of data into a map Decrease in low cost of disks the

development of high-density storage media Data sets on common server solves storage

problems accessible to multiple users

Data storage

Projection is a fundamental component of map making

Transferring information from earth’s 3 D to 2 D medium (paper or computer screen)

Projection and registration

GIS convert data from one structure to another

Satellite image is converted into readable form in raster format

Raster files can be easily read by the computer

Data structures

1 1 1 1 1 3 3 3

1 1 1 1 1 1 3 3

1 1 1 2 2 1 3 3

1 1 1 2 2 2 3 3

1 1 1 2 2 2 3 3

1 1 1 2 2 3 3 3

1 1 1 1 1 1 3 3

1 1 1 1 1 1 3 3

Samples taken in discrete location Used to depict 2D, 3D of earth’s surface It is easy to locate the different area with pH

value of oil and also soil

Data modeling

Support the retrieval of features or by spatial characteristics

Position of a single feature Buffering is a action that retrieves within a

specified distance of a line, point or area

Data retrieval

Spreadsheet and database analysis Computing new attributes Generating summary statistics Creating reports

Data analysis

GIS is automated map making technology Prolific producer of maps GIS user can change scale at a push of a

button But controlling the content is not so easy

Map making

Environmental studies, geography, geology, planning, business marketing

Help to analyze large datasets Better understanding of terrestrial process Human activities to improve economic

vitality and environmental quality

Application