First launched in 1972, the LANDSAT satellite series constitutes one of the longest
continuous records in Earth observation. The objective of the LANDSAT program has
always been to provide multi-spectral imagery of the Earth's land areas at moderate
to high resolution, (28.50 - 90.00 meter horizontal resolution) to support resource
assessment, land-cover mapping, and to track inter-annual changes in the environment.
Applications of LANDSAT data are quite diverse, comprising Earth Science, commercial
applications, mining applications, government and military use. A few examples include
mapping land-cover change (forest change, urbanization, etc), monitoring agricultural
productivity, monitoring wetland health, mapping geologic resources, and targeting
habitats for vector-borne disease eradication. LANDSAT is a cornerstone of NASA's
Earth Observing System, providing moderate-resolution to high-resolution images.
- Multi-spectral Scanner (LANDSAT MSS)
The MSS was a cross-track, (whiskbroom), scanner that acquired imagery in four channels
(2 visible, 2 near-infrared) at 79.00-meter resolution. The MSS was included on
Landsat-1 through Landsat-5.
- Thematic MAPPER (LANDSAT TM)
The TM was flown on Landsat-4 and Landsat-5. The TM is a cross-track scanner providing
seven multi-spectral channels, (3 visible, 1 near-infrared, 2 mid-infrared, 1 thermal-infrared),
at 30.00-meter resolution (120.00-meter resolution for the thermal-infrared band).
- Enhanced Thematic MAPPER Plus (LANDSAT ETM+)
The ETM+ instrument currently flying on Landsat-7 is similar to the earlier TM,
but adds an extra 14.25-meter resolution panchromatic band, and improved resolution
for the thermal-infrared band (57.00-meters).
LANDSAT imagery is relatively high-resolution earth observation data that is acquired
through sensors on one of the NASA LANDSAT satellites. The satellite sensors acquire
high integrity images of the planet surface in a systematic fashion. Users can take
this imagery and use it to determine the health and type of vegetation, amount of
built surfaces, success of agriculture, or apply it for a myriad other uses like
various geological derived applications as well as various mineral exploration activities.
Orbit and Acquisition Characteristics
|
Satellite |
Sensor |
Swath (km) |
Scene Size (km) |
Altitude (km) |
Revisit (days) |
|
LANDSAT 1-5 |
MSS |
180 |
180 x 170 |
917 |
18 |
|
LANDSAT 4-5 |
TM |
185 |
170 x 183 |
705 |
18 |
|
LANDSAT 7 |
ETM+ |
185 |
170 x 183 |
705 |
16 |
Spectral Resolutions & Spatial Resolutions
|
Satellite |
Spectral Resolution (ยต) |
Band |
Spatial Resolution |
|
LANDSAT 1-3 |
MSS |
|
(Meters) |
|
|
Band 4: 0.50 - 0.60 |
Green |
79.00 Meter Resolution |
|
|
Band 5: 0.60 - 0.70 |
Red |
79.00 Meter Resolution |
|
|
Band 6: 0.70 - 0.80 |
Near IR |
79.00 Meter Resolution |
|
|
Band 7: 0.80 - 1.10 |
Near IR |
79.00 Meter Resolution |
|
LANDSAT 4-5 |
MSS |
|
|
|
|
Band 4: 0.50 - 0.60 |
Green |
82.00 Meter Resolution |
|
|
Band 5: 0.60 - 0.70 |
Red |
82.00 Meter Resolution |
|
|
Band 6: 0.70 - 0.80 |
Near IR |
82.00 Meter Resolution |
|
|
Band 7: 0.80 - 1.10 |
Near IR |
82.00 Meter Resolution |
|
|
TM |
|
|
|
|
Band 1: 0.45 - 0.52 |
Blue |
30.00 Meter Resolution |
|
|
Band 2: 0.52 - 0.60 |
Green |
30.00 Meter Resolution |
|
|
Band 3: 0.63 - 0.69 |
Red |
30.00 Meter Resolution |
|
|
Band 4: 0.76 - 0.90 |
Near IR |
30.00 Meter Resolution |
|
|
Band 5: 1.55 - 1.75 |
Mid IR |
30.00 Meter Resolution |
|
|
Band 6: 10.4 - 12.5 |
Thermal |
120.00 Meter Resolution |
|
|
Band 7: 2.08 - 2.35 |
Mid IR |
30.00 Meter Resolution |
|
LANDSAT 7 |
ETM+ |
|
|
|
|
Band 1: 0.450 - 0.515 |
Blue |
28.50 Meter Resolution |
|
|
Band 2: 0.525 - 0.605 |
Green |
28.50 Meter Resolution |
|
|
Band 3: 0.630 - 0.690 |
Red |
28.50 Meter Resolution |
|
|
Band 4: 0.760 - 0.900 |
Near IR |
28.50 Meter Resolution |
|
|
Band 5: 1.550 - 1.750 |
Mid IR |
28.50 Meter Resolution |
|
* |
Band 6: 10.40 - 12.5 |
Thermal |
57.00 Meter Resolution |
|
|
Band 7: 2.080 - 2.35 |
Far IR |
28.50 Meter Resolution |
|
|
Panchromatic |
|
|
|
|
Band 8: 0.52 - 0.92 |
Pan |
14.25 Meter Resolution |
* Note: Band 6 on LANDSAT 7 is divided into two bands, high and low gain.
Imagery from the LANDSAT satellites has been acquired since 1972, with a variety
of characteristics to consider. There have been six operational LANDSAT satellites,
with three different useful sensors, all of which are available from Geoscientific
Trust. The MSS sensor provides the oldest and lowest quality LANDSAT data and images
are available from 1972. The TM sensor has improved quality and images are available
from 1984. The ETM+ sensor on the LANDSAT 7 satellite remains the best quality of
all the sensors.
LANDSAT imagery is acquired in a very precise manner, to better emphasize particular
land cover aspects. Some of the parameters of this precision involve a scene's radiometry,
providing distinct characteristics to components of the image scene. These measures
help determine what the images are good for, from a science perspective.
For example,
Bands 1, 2 and 3 are used together to approximate how the real world appears. Bands
4, 5 or 7 from ETM+ are used in combination with 1, 2 or 3 to demonstrate vegetation
conditions.
LANDSAT imagery is provided to the user by Geoscientific in a specific series of
formats, all of which are designed for maximum coverage of users who have access
to basic graphical software, (please note that we supply two basic software packages
to all new clients on a 'no cost basis' when LANDSAT satellite images are ordered
from Geoscientific).
Each LANDSAT scene is available with bands as separate files, (.tiff format - split
layers / files - BSQ Band Sequential Format). A Geo-TIFF file can be used as a TIFF
file in any graphical software, or if the client has spatial software the images
will be supplied as either. Tiff or .IMG file extensions.
The geo-reference formats employed by Geoscientific for LANDSAT imagery include
a UTM projection and a WGS84 datum and ellipsoid. In addition to this geo-referenced
information, all LANDSAT image files acquired from Geoscientific will have been
processed using a re-sampling technique, namely 'Cubic Convolution' that greatly
enhances the visibility of many ground features.