Thematic Mapper Landsat Data

Table of Contents

[Background](#tm1)

[Extent of Coverage](#tm2)

[Acquisition](#tm3)

[Processing Steps](#tm4)

[Data Characteristics](#tm5)

[Spatial Resolution](#tm6)

[Temporal Coverage](#tm7)

[Spectral Range](#tm8)

[Data Organization](#tm9)

[Data Availability](#tm10)

[Procedures for Obtaining Data](#tm11)

[Products and Services](#tm12)

[Applications and Related Data Sets](#tm13)

[References](#tm14)

[Appendix](#tm16)

[]{#tm1 .anchor}**Background**

The U.S. Geological Survey\'s [(USGS)](../../glossary/u_z#usgs)
[EROS](../../glossary/e_g#eros) Data Center
[(EDC)](../../glossary/e_g#edc) has managed the Landsat data archive for
more than two decades. This archive provides a rich collection of
information about the Earth\'s land surface. Major characteristics and
changes to the surface of the planet can be detected, measured, and
analyzed using Landsat data. The effects of desertification,
deforestation, pollution, cataclysmic volcanic activity, and other
natural and anthropogenic events can be examined using data acquired
from the Landsat series of Earth-observing satellites. The information
obtainable from the historical and current Landsat data play a key role
in studying changes to the Earth\'s surface.

This document provides an overview of the Landsat program and
illustrates the application of the data to monitor changes occurring on
the surface of the Earth. Landsat multispectral scanner
[(MSS)](../../glossary/m_o#mss) data provide a historical record of the
Earth\'s land surface from the early 1970\'s to the early 1990\'s.
Landsat thematic mapper [(TM)](../../glossary/s_t#tm) data provide land
surface information from the early 1980\'s to the present.

A Brief History of the Landsat Program

The idea of a civilian Earth resources satellite was conceived in the
Department of Interior in the mid-1960\'s. The National Aeronautics and
Space Administration [(NASA)](../../glossary/m_o#nasa) embarked on an
initiative to develop and launch the first Earth monitoring satellite to
meet the needs of resource managers and Earth scientists. The USGS
entered into a partnership with NASA in the early 1970\'s to assume
responsibility for the archive management and distribution of Landsat
data products. On July 23, 1972, NASA launched the first in a series of
satellites designed to provide repetitive global coverage of the
Earth\'s land masses. Designated initially as the Earth Resources
Technology Satellite-A [(ERTS](../../glossary/h_l#landsat)-A), it used a
[Nimbus](../../glossary/m_o#nimbus)-type platform that was modified to
carry sensor systems and data relay equipment. When operational orbit
was achieved, it was designated ERTS-1.

The satellite continued to function beyond its designed life expectancy
of 1 year and finally ceased to operate on January 6, 1978, more than 5
years after its launch date. The second in this series of Earth
resources satellites (designated ERTS-B) was launched January 22, 1975.
It was renamed Landsat 2 by NASA, which also renamed ERTS-1 to
Landsat 1. Three additional Landsats were launched in 1978, 1982, and
1984 (Landsats 3, 4, and 5 respectively). Each successive satellite
system had improved sensor and communications capabilities.

NASA was responsible for operating the Landsats through the early
1980\'s. In January 1983, operations of the Landsat system were
transferred to the National Oceanic and Atmospheric Administration
[(NOAA)](../../glossary/m_o#noaa). In October 1985, the Landsat system
was commercialized. After that date, all Landsat commercial rights
became the property of [Space Imaging EOSAT](../../glossary/s_t#eosat)
with exclusive sales rights to all thematic mapper (TM) data. Throughout
these changes, the EDC retained primary responsibility as the Government
archive of Landsat data. The Land Remote Sensing Policy Act of 1992
(Public Law 102-555) officially authorized the National Satellite Land
Remote Sensing Data Archive and assigned responsibility to the
Department of Interior. All Landsat data over ten years old is available
from the National Archive at the EROS Data Center. In addition to its
Landsat data management responsibility the EDC investigates new methods
of characterizing and studying changes on the land surface with Landsat
data.

Example image:

[**Glasgow, MO** (115.7 kb)](../../../graphics/guide/landsat_tm/tm.gif)

Characteristics of the Landsat System

Landsats 4 and 5 carry both the MSS and the thematic mapper (TM)
sensors; however, routine collection of MSS data was terminated in late
1992. They orbit at an altitude of 705 km and provide a 16-day,
233-orbit cycle with a swath overlap that varies from 7 percent at the
Equator to nearly 84 percent at 81 north or south latitude. These
satellites were also designed and operated to collect data over a 185 km
swath. The MSS sensors aboard Landsats 4 and 5 are identical to the ones
that were carried on Landsats 1 and 2. The MSS and TM sensors primarily
detect reflected radiation from the Earth surface in the visible and
near-infrared (IR) wavelengths, but the TM sensor provides more
radiometric information than the MSS sensor. The wavelength range for
the TM sensor is from the visible (blue), through the mid-IR, into the
thermal-IR portion of the [electromagnetic
spectrum.](../%0D%0D../glossary/e_g#ems) Sixteen detectors for the
visible and mid-IR wavelength bands in the TM sensor provide 16 scan
lines on each active scan. Four detectors for the thermal-IR band
provide four scan lines on each active scan. The TM sensor has a spatial
resolution of 30 m for the visible, near-IR, and mid-IR wavelengths and
a spatial resolution of 120 m for the thermal-IR band.

All of the Landsats have been in sun-synchronous orbits with equatorial
crossing times ranging from 8:30 a.m. for Landsat 1, 9 a.m. for Landsat
2, to 9:45 a.m. for Landsat 5.

[**Landsat Orbit** (29.4 kb)](../../../graphics/guide/landsat/orbit.gif)

[]{#tm2 .anchor}**Extent of Coverage**

The Landsat system provides for global data between 81 degrees north
latitude and 81 degrees south latitude.

[]{#tm3 .anchor}**Acquisition**

The Landsat platforms operate from a sun-synchronous, near-polar orbit
imaging the same 185 km (115 miles) ground swath every 16 days. Thematic
mapper (TM) data are received directly from Landsats 4 and 5 by a
network of 16 worldwide ground stations. The United States ground
station in Norman, Oklahoma, receives TM downlinks daily, and records
them on high density tapes [(HDTS)](../../glossary/h_l#hdt). These HDTs
are then sent to [Space Imaging EOSAT\'s](../../glossary/s_t#eosat)
Image Processing Facility (IDPF) located in Lanham, Maryland. Also, data
are transmitted via a Tracking and Data Relay Satellite
[(TDRS)](../../glossary/s_t#tdrs) to its ground terminal at White Sands,
New Mexico, and then relayed via a domestic communications satellite
[(DOMSAT)](../../glossary/c_d#domsat) to the Space Imaging EOSAT data
processing facility in Norman, Oklahoma.

The TDRS System [(TDRSS)](../../glossary/s_t#tdrs) satellites are in
geosynchronous orbits. This configuration allowed the acquisition of MSS
data for nearly all of the Earth\'s surface, except for an area between
50 degrees north and 67 degrees east by 50 degrees south and 82 degrees
east. That area may be covered in part by data recorders at the Thailand
and India ground stations.

[**TDRS Coverage Gap** (8.7
kb)](../../../graphics/guide/landsat_tm/tdrs.gif)

[]{#tm4 .anchor}**Processing Steps**

The Space Imaging EOSAT Image Data Processing Facility in Lanham,
Maryland, receives the HDTs from the Norman, Oklahoma, acquisition
facility. The newly acquired data are manually and automatically
screened for cloud cover and data quality through the Preprocessing and
Data Classification System (PDCS). HDTs that are required for customer
products continue through the image processing stream. The remaining
data are stored locally for approximately six months; after temporary
storage, they are permanently archived in Jessup, Maryland. The HDTs are
also shipped to the EDC where they are copied and the original returned
to the Space Imaging EOSAT.

Systematic correction data (SCD) is generated as follows:

\- Correcting and validating the mirror scan and payload

correction data

\- Providing for image framing by generating a series of

scene center parameters

\- Synchronizing telemetry data with video data

\- Estimating linear motion deviation of scan mirror/scan

line corrections

\- Generating benchmark correction matrices for specified map

projections

\- Producing along- and across-scan high-frequency line matrices

The Space Imaging EOSAT Image Processing System
[(EIPS)](../../glossary/e_g#eips) has the capability to produce
precision-corrected, geocoded, mosaicked, and terrain-corrected
products. Insufficient control points in the Control Point Library
[(CPT)](../../glossary/c_d#cp) requires a single band (Band 4) tape be
produced and processed on the Control Point Extraction System
[(CPES)](../../glossary/c_d#cpes) for control point
[(chip)](../../glossary/c_d#chip) selection. Upon successful completion,
the product is reprocessed via the EIPS. Digital elevation model
[(DEM)](../../glossary/c_d#dem) and digital terrain model
[(DTM)](../../glossary/c_d#dtm) data are ingested through EIPS for
terrain-corrected and mosaic products.

A 3-band digital data tape is provided with each film product request
and is used in the Film Process Generation System (FPGS). The 3-band
digital data are ingested, Look Up Tables (LUTs) are constructed, and
the ordered RGB is assigned for output. The latent image is processed
using a Colorfire-240. Further processing is completed per customer
request and tranported via a commercial vendor. These products include:
paper print, color positive, transparency, or processed negative.

The Space Imaging EOSAT initiated a Fast Format for TM digital data. The
general formatting criteria follows:

1.  Field definitions strictly follow American National Standards
    Institute [(ANSI)](../../../hyper/glossary/a_b#ansi) and
    International Organization for Standardization
    [(ISO)](../../../hyper/glossary/h_l#iso) standards.

```{=html}
<!-- -->
```
1.  Only Band Sequential [(BSQ)](../../../hyper/glossary/a_b#bsq) image
    structure is supported, because data are made available a single
    band at a time. Geometric corrections to the data are done one band
    at a time.

2.  Image files consist of a single band of data.

3.  A digital product is referred to as a volume set. Individual tapes
    are referred to as volumes. A volume set may have one or more
    volumes depending on image size and output tape density.
    Multi-resolution data sets have a volume set for each resolution.

For further information on the MSS processing systems refer to:

-   [EROS Digital Image Processing System (EDIPS)](../edips.html)

-   [National Landsat Archive Production System (NLAPS)](../nlaps.html)

[]{#tm5 .anchor}**Data Characteristics**

Since 1972 these satellites have provided repetitive, synoptic, global
coverage of high-resolution multispectral imagery. The characteristics
of the MSS and TM bands were selected to maximize their capabilities for
detecting and monitoring different types of Earth resources. For
example, TM band 2 can detect green reflectance from healthy vegetation,
and band 3 of TM is designed for detecting chlorophyll absorption in
vegetation. TM band 4 is ideal for near-IR reflectance peaks in healthy
green vegetation and for detecting water-land interfaces. TM band 1 can
penetrate water for bathymetric mapping along coastal areas and is
useful for soil-vegetation differentiation and for distinguishing forest
types. The two mid-IR red bands on TM (bands 5 and 7) are useful for
vegetation and soil moisture studies, and discriminating between rock
and mineral types. The thermal-IR band on TM (band 6) is designed to
assist in thermal mapping, and for soil moisture and vegetation studies.

Typically, TM Bands 4, 3, and 2 can be combined to make false-color
composite images where band 4 represents red, band 3, green, and band 2,
blue. This band combination makes vegetation appear as shades of red,
brighter reds indicating more vigorously growing vegetation. Soils with
no or sparse vegetation will range from white (sands) to greens or
browns depending on moisture and organic matter content. Water bodies
will appear blue. Deep, clear water will be dark blue to black in color,
while sediment-laden or shallow waters will appear lighter in color.
Urban areas will appear blue-gray in color. Clouds and snow will be
bright white. They are usually distinguishable from each other by the
shadows associated with the clouds.

[]{#tm6 .anchor}**Spatial Resolution**

A Landsat 4 and 5 TM scene has an instantaneous field of view
[(IFOV)](../../glossary/h_l#ifov) of 30 square meters in bands 1 through
5 and band 7, band 6 has an IFOV of 120 square meters on the ground.

The resolution for the TM sensor is shown below:

Resolution

Landsats 4-5 (meters)

Band 1 30

Band 2 30

Band 3 30

Band 4 30

Band 5 30

Band 6 120

Band 7 30

[]{#tm7 .anchor}**Temporal Coverage**

Background information and status of Landsat satellites.

Satellite Launched Decommissioned Sensors

Landsat 1 July 23, 1972 January 6, 1978 MSS and
[RBV](../../glossary/p_r#rbv)

Landsat 2 January 22, 1975 February 25, 1982 MSS and RBV

Landsat 3 March 5, 1978 March 31, 1983 MSS and RBV

Landsat 4 July 16, 1982 \* TM and MSS

Landsat 5 March 1, 1984 \*\* TM and MSS

\* in standby mode used for range and command as of December 14, 1993.

\*\* currently operational

[]{#tm8 .anchor}**Spectral Range**

The thematic mapper (TM) is an advanced, multispectral scanning, Earth
resources sensor designed to achieve higher image resolution, sharper
spectral separation, improved geometric fidelity, and greater
radiometric accuracy and resolution than the MSS sensor. TM data are
scanned simultaneously in seven spectral bands. Band 6 scans thermal
(heat) infrared radiation.

Radiometric range of bands and resolution for the TM sensor (from
Landsat 4 Data Users Handbook, 1984, USGS).

Wavelength Resolution

Landsats 4-5 (micrometers) (meters)

Band 1 0.45-0.52 30

Band 2 0.52-0.60 30

Band 3 0.63-0.69 30

Band 4 0.76-0.90 30

Band 5 1.55-1.75 30

Band 6 10.40-12.50 120

Band 7 2.08-2.35 30

[Micrometers](../../glossary/m_o#micrometers) and their relationship to
the [electromagnetic spectrum](../../glossary/e_g#ems) are explained in
the glossary.

[]{#tm9 .anchor}**Data Organization**

The Space Imaging EOSAT Fast Format volume set contains a header file,
image files, and a trailer file.

The first file on each volume, a Read-Me-First file, contains header
data. It is in American Standard Code for Information Interchange
[(ASCII)](../../glossary/a_b#ascii) format and adheres to
[ANSI](../../glossary/a_b#ansi) and [ISO](../../glossary/h_l#iso)
standards. The header file contains a single 1536-byte ASCII record. All
alphanumerics are left justified, and all numerics are right justified.

All image files contain only one TM band of image pixels. There are no
header records within the image file, nor are there prefix and/or suffix
data in the individual image records. Image data may be blocked or
unblocked.

The blocking factor is a procedure used to minimize the number of
digital tapes required to accommodate a full-scene seven-band image set.
Image data are written to tape in individual records and between each
record is an inter-record gap (IRG), 0.35 of an inch, separating image
file records. Unblocked data contain one line of image data per tape
record.

The last volume of the Fast Format image set includes a trailer file.
The trailer file contains ephemeris information to compute the
approximate spacecraft position for each pixel in the image. This file
is in ASCII format and adheres to ANSI and ISO standards.

The structure for a single-volume and a multi-volume set are presented
below. Each file is followed by an End-Of-File (EOF) marker. An
End-Of-Volume (EOV) marker consists of three EOFs.

Single Volume Multi Volume

Volume Set Volume Set

Volume 1 Volume 2

Header File Header File Header File

EOF EOF EOF

Band 1 Band 1 Band 5

EOF EOF EOF

Band 2 Band 2 Band 6

EOF EOF EOF

Band 3 Band 3 Band 7

EOF EOF EOF

Band 4 BAND 4 EOV

EOF EOF Trailer File

Band 5 EOV

EOF Trailer File

Band 6

EOF

Band 7

EOF

EOV

Trailer File

[]{#tm10 .anchor}**Data Availability**

[]{#tm11 .anchor}**Procedures for Obtaining Data**

To place orders and to obtain additional information regarding technical
details, ancillary products, and pricing schedules, contact: [Customer
Services, EROS Data Center](../../address/addresses#customer)

The GLIS INVENTORY and ORDER screens also may be used for further
information on ordering Thematic Mapper data.

[]{#tm12 .anchor}**Products and Services**

The EROS Data Center offers TM digital products on 8 mm cartridge tapes
and Compact Disc Recordables, (CDRs).

The following products and prices will be offered by USGS-EDC to U.S.
Governmentand its Affiliated Users (USGAU). This group is comprised of
U.S. Government agencies; U.S. Government contractors; researchers
involved with the U.S. Global Change Research Program and its
international counterpart programs; and other researchers and
international entities that have signed with the U.S. Government a
cooperative agreement involving the use of Landsat data for
noncommercial purposes.

All prices listed in the table are based on the TM data physically
residing in the National Land Remote Sensing Data Archive (NSLRSDA) at
EDC; the HDT access fee does not apply.

However, an HDT Access Fee must be added to the listed product price for
all TM scenes that were acquired after October 28, 1992 and are not
physically in the NSLRDA at the EDC. The HDT Access Fee is equal to \$70
times the number of scenes on each HDT that must be purchased from Space
Imaging EOSAT to fulfill the order. NOTE: No HDT access fee will be
applied for the TM data acquired after October 28, 1992, if the data
physically resides in the NSLRSDA.

DESCRIPTION PRICE

+\-\-\-\-\-\-\-\-\-\--+ +\-\-\-\--+

TM Level 0 Raw \$300.00

TM Level 1 NASA/CCRS \$300.00

TM Systematic Single \$425.00

TM Systematic Multiple \$425.00 + \$200.00 each additional scene

MSS Systematic Single \$200.00

MSS Systematic Multiple \$200.00 + \$120.00 each additional scene

TM Map Reg. Single \$600.00

TM Map Reg. Multiple \$600.00 + \$360.00 each additional scene

MSS Map Reg. Single \$375.00

MSS Map Reg. Multiple \$375.00 + \$225.00 each additional scene

TM Terrain-Cor Single \$900.00

TM Terrain-Cor Multiple \$900.00 + \$360.00 each additional scene

MSS Terrain-Cor Single \$675.00

MSS Terrain-Cor Multiple \$675.00 + \$225.00 each additional scene

The following are the only products that will be offered by the USGS-EDC
to the General Public. The General Public has access to only 10-year and
older data and all of these data physically reside in the NSLRSDA at
EDC, therefore, no HDT access fee applies.

DESCRIPTION PRICE

+\-\-\-\-\-\-\-\-\-\--+ +\-\-\-\--+

TM Systematic Single \$425.00

TM Systematic Multiple \$425.00 + 200.00 each scene

MSS Systematic Single \$200.00

MSS Systematic Multiple \$200.00 + \$120.00 each additional scene

Determine your Customer Category (general public or USGAU) and Date of

Sensing of the scene to be ordered and use the tables to determine the

distribution site (USGS-EDC or Space Imaging EOSAT).

+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

\| \| \| \|

\|July 16, 1982 \| 10 years ago \| 1 year ago \|

\| to \| to \| to \|

\| 10 years ago \| 1 year ago \| Present \|

+\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

\|General Public \| USGS-EDC \| Space Imaging EOSAT \| Space Imaging
EOSAT\|

+\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

\| USGAU \| USGS-EDC \| USGS-EDC \| Space Imaging EOSAT\|

+\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

Effective October 1, 1996

+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

\| July 16, 1982 \| 10 years ago \|

\| to \| to \|

\| 10 years ago \| Present \|

+\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

\|General Public \| USGS-EDC \| Space Imaging EOSAT\|

+\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

\| USGAU \| USGS-EDC \| USGS-EDC \|

+\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--+

[Space Imaging EOSAT](../../glossary/s_t#eosat) thematic mapper products
consist of black and white and color film and paper products and various
digital products.

[]{#tm13 .anchor}**Applications and Related Data Sets**

Landsat data have been used by government, commercial, industrial,
civilian, and educational communities in the U.S. and worldwide. They
are being used to support a wide range of applications in such areas as
global change research, agriculture, forestry, geology, resources
management, geography, mapping, water quality, and oceanography. Landsat
data have potential applications for monitoring the conditions of the
Earth\'s land surface. The images can be used to map anthropogenic and
natural changes on the Earth over periods of several months to more than
15 years. The types of changes that can be identified include
agricultural development, deforestation, natural disasters,
urbanization, and the development and degradation of water resources.
The [MSS](../../guide/landsat) archive has over 630,000 scenes with a
data volume of 20 terabytes. The TM archive has over 300,000 scenes with
a data volume of over 50 terabytes.

[**TM Scene (59.2 kb)**](../../../graphics/guide/landsat_tm/tm2.gif)

[]{#tm14 .anchor}**References**

Earth Observation Satellite Company, 1985, User\'s guide for Landsat
thematic mapper computer-compatible tapes: Lanham, Md., Earth
Observation Satellite Company \[variously paged\].

Earth Observation Satellite Company, 1994, Landsat system status
report\--September 1994: Lanham, Md., Earth Observation Satellite
Company, p. 1-11.

National Aeronautics and Space Administration, 1981, Draft Landsat-D
worldwide reference system (WRS) users guide: \[Greenbelt, Md.\],
National Aeronautics and Space Administration \[variously paged\].

National Oceanic and Atmospheric Administration, 1983, Landsat data
users notes: \[Sioux Falls, S. Dak.\], National Oceanic and Atmospheric
Administration \[variously paged\]

U.S. Geological Survey and National Oceanic and Atmospheric
Administration, 1984, Landsat 4 data users handbook: \[Washington,
D.C.\], U.S. Geological Survey and National Oceanic and Atmospheric
Administration \[variously paged\].

[]{#tm16 .anchor}**Appendix**

-   [Worldwide Reference System (WRS)](../wrs.html)