The Operational System 
There has been much interest in an operational system for Landsat data. 
The definition of a Landsat "operational system" encompasses 6 major 
components, operating routinely and continually for an indefinite period 
of time. 
The 6 major elements are: 
a. satellite and sensor system; 
b. communications and data links; 
c. data preprocessing (radiometric and geometric corrections); 
d. data distribution system; 
e. data analysis processing (transforming data to information); 
and, 
f. beneficial use of the information. 
While some users have been reluctant to invest in a data analysis system 
and commit to use of operational data without assurance of a continuing 
data source, many have been using the data products from the experimental 
Landsats-1 and -2 routinely, in many cases with significant benefit to 
their businesses and activities. 
The results of cooperative NASA-user programs in developing data analysis 
techniques and the continuing improvement in data products should contri- 
bute to the commitment to operational readiness by many more users in 
the next several years. 
Landsat-D, with both the multispectral scanner and the higher performance 
TM, is to start operation in 1981. Based on experience with Landsat 
satellites, Landsat-D is expected to provide data at least through about 
1984. Also under development is a backup Landsat-D satellite which would 
extend the Landsat capability to about the 1987 time period,if approved 
for launch and operation. With the capability of the Space Shuttle to 
retrieve satellites and repair malfunctions, the effective life of the 
Landsat satellite capability may be extended even longer. 
NASA-FOREIGN COUNTRY LANDSAT GROUND STATIONS AGREEMENTS