Prepared by:

NIZAM_UD_DIN

B. Sc . ( Hons.)

Department of

Space Science

What is landsat ?

“Land” mean earth

“Sat” means satellite

So landsat means earth satellite or

earth observing satellite

Introduction

Landsat was designed in 1960s by the combined

effort of NASA and US.

Launched in 1972 as the 1st tailored Satellite,

specifically for broad scale observation of the

Earth’s Land areas. Six satellite have been launched successfully, namely

Landsat -1 to -5 and Landsat -7

Landsat-6 suffered a launch failure.

Five different types of sensor used namely

RBV,MSS,TM,ETM and ETM+.

Object

To acquire data about earth resources on a

Systematic,

Repetitive,

Medium resolution,

Mulitispectral basis's

All data can be collected in accordance with an

“open skies” principle.Meaning ,there would be nondiscriminatory access to data

collect anywhere in the world

Satellite Launched End of

service

Sensors

Landsat 1 23 July 1972 6 Jan. 1978

MSS(1-3)

RBV(4-7)

Landsat 2 22 jan.1975 25 jan.1982

MSS(1-3)

RBV(4-7)

Landsat 3 5 march 1978 3 march 1983

MSS(1-3)

RBV(4-7)

Characteristics

• Butterfly shaped , sun-synchronous

• 3 meter tall , 1.5 m in Diameter with solar panels extending about 4 meter

• Satellite weighed about 815 Kg

• Altitude 919 Km

• Orbital inclination is 99 degree

• Orbits cycle is 18 days

• Orbital period is 103 min. or 14 orbits per day

• Ground track speed is 6.46 km/sec.

• Cross the equator at a time 9.30 to 10.00am

Satellite launched End of service sensors

Satellite 4 6 July 1982

Transmission of TM data

failed in August 1993

MSS (1-4),

TM (1-7)

Satellite 5 1 march 1984

Transmission by direct

downlink only

MSS (1-4),

TM (1-7)

Characteristics

• Like Landsat,1-3 Landsat,4-5 are repetitive,

circular, sun-synchronous, near polar orbits.

• Altitude 705Km

• Orbital inclination is 98.2 degree

• Orbital period is 99 min. or 14.5 orbits per day.

• Orbits cycle is 16 days

• Cross the equator on north-south portion of each

orbit at a time 9.45am 10.00am local sun time.

Landsat-6

Satellite launched End of

service

sensors

Landsat-6 5 oct.1993

Failure

upon launch

ETM+ (1-7

plus pan-

chromatic )

Characteristics are same as Landsat-4and-5

Landsat-7

Satellite launched

End of

service sensors

Landsat-7 15 April

1993

ETM+ (1-7

plus pan-

chromatic )

Characteristics are same as Landsat-4and-5

Landsat-7

• Landsat-7 is a three-axis stabilized platform caring a

single nadir-pointing instrument the ETM+ .

• It is bases on scanning technology despite the fact that

linear “push-broom” technology.

• It acquires every day time scene on every pass over the

United States (US).

• It is operating .

• It has similar orbits characteristic to Landsat-4 and-5.

Landsat sensors

Sensors:

sensors that observe the earth

and then transmit information by microwave

signals to ground stations that receive and

process data for dissemination to a community of data users.

• Landsat sensors recorded energy in the visible & near Infrared spectrum.

RETURN BEAM VIDICON (RBV)

• RBV have high spatial resolution and geometric accuracy but lower spectral

and radiometric resolution.

• It is camera like instrument .

• Position of feature would be accurately represented.

• RBV sensor could acquire an image every 25 seconds to produce a series of images with a small forward overlap.

• Function of RBV was primarily to provide data for accurate measurement of position and distance.

• Disadvantage:RBV operations were plagued with

various technical problems.

Sensor characteristics

Landsat-1-2

Resolution Band # Spectral sensitivity

80 m 1 0.475-0.575 micrometer

(Green)

80 m 2 0.58-0.68 micrometer

(Red)

80 m 3 0.69-0.75 micrometer

Near infrared

Landsat-3

30 m 0.5-0.75 micrometer

(panchromatic response)

Multispectral Scanner (MSS)

Landsat-1-2 and-3

Spatial

Resolution

Band # Spectral

Resolution

Radiometric

sensitivity

79 m 4 0.50-0.6µm

(Green)

0.57

79 m 5 0.6-0.7 µm

(Red)

0.57

79 m 6 0.7-0.8 µm

Near infrared

0.65

79 m 7 0.8-1.1 µm

Near infrared

0.70

Landsat-3

Spatial

Resolution

Band # Spectral

Resolution

Radiometric

sensitivity

240 m 8 10.4-12.6

µm (Far IR)

1.4K(NEΔT)

NEΔT: Noise equivalent temperature

Multispectral Scanner (MSS)

Landsat-4-5-6 and 7

Spatial

Resolution

Band # Spectral

Resolution

Radiometric

sensitivity

79 m 1 0.50-0.6µm

(Green)

0.57

79 m 2 0.6-0.7 µm (Red) 0.57

79 m 3 0.7-0.8 µm Near

infrared

0.65

79 m 4 0.8-1.1 µm

Near infrared

0.70

MSS

• MSS system were the 1st global monitoring systems of producing multispectral data in digital format.

• It covered several tens of billions of square Kms of the earth' surface.

• MSS sensors use a wishb-broom design.

• It is an optical mechanical system in which a mirror scans the terrain perpendicular to the flight direction.

• It scans focuses radiant flux from terrain onto discrete detectors elements.

• These detectors convert the radiant flux into electronic signals .

• It has four sets of filters and detectors.

Working

• MSS scanning mirror oscillate through an angular

displacement of ±5.78° off-nadir.

• So 11.56° field of view resulted in a swath 185 Km for

each orbit .

• When not viewing the earth ,the MSS detectors were

exposed to internal light and sun calibration sources .

• One scene has about 7.6 million pixels ,recorded in 27

seconds.

• Landsat scene are referenced by orbital path (numbered

0-255 east to west) and row (numbered from north to

south, with row 60 at the equator).

CharacteristicsIFOV at Nadir 79×79 for Bands(1-7)

240×240 for Bands(8)

Date Rate 15 M bite/sec.

Quantization level 6 bit (values from 0-63)

Earth coverage 18 days (Landsat-1-2 and-3)

16 days (Landsat-4,5)

Altitude 919 Km

Swath width 185 Km

Inclination 99°

Thematic Mapper (TM)Landsat-4 and-5

Band # Spatial

Resolution

Spectral

Resolution

Radiometric

sensitivity

1 (Blue) 30 m 0.45-0.52 µm 0.8

2 (Green) 30 m 0.52-0.60 µm 0.5

3 (Red) 30 m 0.63-0.69 µm 0.5

4 (NIR) 30 m 0.76-0.90 µm 0.5

5 (mid-IR) 30 m 1.55-1.75 µm 1.0

6 (Thermal

IR)

120 m 10.40-12.5 µm 0.5(NEΔT)

7 (mid-IR) 30 m 2.08-2.35 µm 2.4

Application

Band #

1

Used for best water penetration, coastal mapping,

vegetation,

Cultural features.

2 Reflected by vegetation ,cultural feature .

3 Chlorophyll absorption region , vegetation ,cultural

feature .

4 Reflected by vegetation, absorbed by water ,vegetation,

,soil moisture assessment.

5 Absorbed by water, moisture

6 Operational on night side of orbit also thermal mapping.

7 Largely redundant with band 5 ,geological classification.

TM Characteristics

IFOV at Nadir 30×30 for Bands(1-5,7)

120×120 for Bands (8)

Date Rate 85 M bite/sec.

Quantization level 8 bit (values from 0-255)

Earth coverage 16 days (Landsat-4,5)

Altitude 705 Km

Swath width 185 Km

Inclination 98.2°

Thematic Mapper (TM)

• TM was based upon the same principle as the MSS,

but had more complex design.

• It provides finer spatial resolution , improved geometric fidelity,

greater radiometric detail and more detailed spectral information.

Objective:

The objectives were to asses the performance of TM ,to

provide ongoing stability of MSS and continue to foreign data

reception.

TM with MSS maintained a high degree of stability in orientation as a

means of improving geometric qualities of the imagery.

Enhanced Thematic Mapper ( ETM+ )

Landsat-7

Band # Spatial

Resolution

Spectral Resolution

1 (Blue) 30 m 0.450-0.515 µm

2 (Green) 30 m 0.525-0.605 µm

3 (Red) 30 m 0.630-0.690 µm

4 (NIR) 30 m 0.750-0.900 µm

5 (mid-IR) 30 m 1.55-1.75 µm

6 (Thermal IR) 120 m 10.40-12.50 µm

7 (mid-IR) 30 m 2.08-2.35 µm

8 (Panchromatic) 15 m 0.52-0.90 µm

ETM+ Characteristics

Sensor Technology Scanning Mirror Spectrometer

Date Rate 250 images per day @ 31450

Kilo square meter

Quantization level 8 bit (values from 0-255)

Earth coverage 16 days

Altitude 705 Km

Swath width 185 Km

Inclination 98.2°

Enhanced Thematic mapper (ETM+)

• It is designed to extend the capabilities of previous TMs

by adding most improvements to the TM’s original

design.

• ETM+ has a 15 m panchromatic channel.

• Like TM,ETM+ scans 16 simultaneous lines per non-

thermal band (32 panchromatic lines ).

• Data acquisition by the ETM+ is directed by the mission

goal of acquiring and updating periodically a global

achieve of day time ,substantially cloud free images of

land areas.

Conclusion

• Since all users are charged standard prices .Often

Landsat data are used in all the world due to free of cost

and more reliable than other satellites.

References

1. Remote Sensing of the Environment

(An earth resource perspective)

Author : John R .Jenson

2. Introduction to Remote Sensing (3rd Edition)

Author : James B.Cambell

3. Remote Sensing and Image Interpretation (4th Edition)

Author : Thomas M.Lillisand and Ralph W.Kiefer