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REVIEW OF SATELLITE REMOTE SENSING PROGRAMS* 
FREDERICK J. DOYLE, President 
International Society for Photogrammetry 
and Remote Sensing 
ABSTRACT 
Satellite remote sensing systems are being developed by several nations. 
Landsat-4 was launched by NASA in July 1982 and is providing high quality 
data from the Multi Spectral Scanner and the Thematic Mapper. Several 
Space Shuttle Missions will have partial remote sensing payloads: syn- 
thetic aperture radar, film cameras, and electro-optical sensors. The 
USSR operates both film cameras in Salyut-7 and electro optical sensors 
on the Meteor spacecraft. France will launch the SPOT satellite with 
high resolution electro-optical sensors. The European Space Agency and 
Japan will launch systems dedicated to marine observations, followed by 
other spacecraft for land observations. India is operating small remote 
sensing satellites and Brazil, Netherlands, and Canada are studying 
future systems. 
Worldwide experience of many individuals and organizations with remote sensing 
data acquired from space, primarily Landsat-1, -2, and -3, has demonstrated its 
utility for land use classification, agricultural assessment, energy and resource 
exploration, and many other applications. On the basis of this favorable expe- 
rience several countries are developing new systems for operation in the decade 
of the 1980s. This review presents the situation at the beginning of 1983. Only 
systems designed for imaging the Earth are included; meteorological satellites 
and other types of non-imaging remote sensing satellites are not covered. 
Landsat-4 
The most significant recent event in satellite remote sensing was the successful 
launch of Landsat-4 on 16 July 1982. The spacecraft was launched by the Delta 
3920 expendable vehicle into a 705 km altitude, 98.29 inclination sun-synchronous 
orbit. As shown in Figure 1, the basic vehicle is the Multi-mission Modular 
Spacecraft (MMS), which provides power supply, attitude control, command and data 
handling, and on-orbit propulsion. The payload consists of the Multi-Spectral 
Scanner (MSS) and the Thematic Mapper (TM). The MSS is essentially the same as 
the instrument carried on Landsats -1, -2, and -3, with four Spectral bands, 80m 
pixel, and 185 km swath. The TM is a second generation multispectral scanner 
having six spectral bands in the visible and short wave infrared wavelengths with 
a 30m pixel, and one band in the thermal infrared wavelength with 120m pixel. 
The TM swath width is also 185 km. The spacecraft has a solar array for power, 
an antenna for use with the Global Positioning System (GPS)**, and a large 
steerable antenna for communication with the Tracking and Data Relay Satellite 
System (TDRSS)***, 
*Extensively revised from earlier version of April 1982. 
**The GPS will eventually consist of an array of 18 separate satellites arranged 
in six different orbital planes at 20,200 km altitude. By real time processing 
of the signals from GPS, it will be possible to determine the position of 
Landsat-4 with a precision of about 15 meters in all three coordinates. GPS 
should be fully operational in 1988. 
***The TDRSS will consist of two communication satellites in geostationary orbits 
at 419 and 1719 west longitude and a single ground station at White Sands, 
New Mexico. Commands from the ground and data from manned and unmanned space- 
craft in low Earth orbit will be transmitted via TDRSS, thus eliminating the 
need for the current NASA Spacecraft Tracking and Data Network (STADAN). TDRSS 
should be operational by Fall 1983. 
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