regarding the TM on-orbit performance. This would allow the 
TIPS development and implementation to proceed based on 
demonstrated performance rather than "hoped for" or specified 
performance. This also eliminated the very real problem of 
resource contention within a single system for MSS 
operations, TM development, and TM R&D. 
DATA PROCESSING FOR THE THEMATIC MAPPER: PROCESS FLOW 
Once the decision to separate the MIPS and TIPS was made, 
the design of TIPS could proceed in earnest. Great success 
was achieved in adapting the MIPS approach. To minimize 
development time and take advantage of proven processes and 
approaches, those that had worked well for MSS and that could 
be adapted to.TIPS were used. Where necessary, new processes 
or approaches were defined. However, it will be seen later 
that the basic technical approach and process flows are quite 
similar. In a simplified form, this can best be illustrated 
by a comparison of the MIPS with the TIPS. Each system can 
be viewed as a series of functions or processes. These are 
summarized in Figure 11 and further described in the text. 
The image generation process flow for MSS and TM are also 
illustrated in Figure 11. Input and process control, data 
base management elements, and processes of the ground system 
common to both MSS and TM processing are not shown. 
Since the MIPS produces no user products, the fundamental 
output of the MIPS is an uncorrected Archival High Density 
Tape, HDTA. As described earlier, the contents of these 
tapes are transmitted from GSFC to the NOAA DDC at EDC daily 
via a domestic communications satellite. At the NOAA DDC the 
data are re-recorded in archival form and all subsequent MSS 
user products are produced at EDC by the EDC Digital Image 
Processing System (EDIPS) and product generation subsystems. 
The TIPS, on the other hand, ingests raw sensor data on 
high density tape (HDTR) and produces not only the archival 
product HDTA but all reproducable master products as well 
(CCT and 241mm film). “The CCT and film prodücts'are then 
mailed to the NOAA DDC where they become a TM product master 
archive. The NOAA DDC is responsible for archiving, final 
product generation and distribution of MSS and TM products. 
The similarities and differences of TIPS and MIPS 
processing can be seen through comparison of individual 
functions within their respective process flow. Certain of 
these functions within TIPS and MIPS are analogous: Payload 
Correction, Archive Generation, Performance Evaluation and 
Control Point Library Build. 
Payload Correction. These functions are analogous for TM 
and MSS in that each function ingests spacecraft 
telemetry (attitude, ephemeris, instrument parameters) 
and produces scene correction data. The similarity ends, 
however, when the extent of the processing required to 
produce TM scene correction data compared to that of MSS 
is examined. The outputs of the MSS Payload Correction 
  
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