Landsat is a series of Earth observation satellite missions jointly managed by NASA and the U.S. Geological Survey. The first Landsat satellite was launched in 1972 and subsequent satellites were launched through 2013 to acquire global land data. Landsat satellites carry imaging sensors to collect medium-resolution multi-spectral images of the Earth's surface on a 16-day repeat cycle. The images are used to observe changes in land use, monitor deforestation, and detect water pollution among other applications. Six Landsat satellites have been launched to date, each carrying improved sensors from the Multi-Spectral Scanner to the Enhanced Thematic Mapper Plus. Landsat provides the longest continuous space-based record of Earth's surface.
2. What is landsat ?
“Land” mean earth
“Sat” means satellite
So landsat means earth satellite or
earth observing satellite
3. 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+.
4. 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
5. 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)
6. 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
7. 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)
8. 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.
9. 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
11. 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.
12. 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.
13. 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.
14. 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)
15. 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
17. 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
18. 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.
19. 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).
20. Characteristics
IFOV 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°
21. 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
22. 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.
23. 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°
24. 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.
25. 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
26. 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°
27. 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.
28. 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.
29. 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