Block diagram of Japanese receiving system for Landsat data 
Fig. 2 
a A ET A) NN PU a I EE ETERNI NEA gcn 
Pc oed ede STEREO A a RT SE ETES CES NE ARR EE OS EE 
1 Kbps PCM data ( house keeping 
and attitude information ). 
Output signals : Signals for the Quick-look unit. 
Signals for the HDDT recording/ 
reproducing unit. 
b) Quick-look unit 
This unit performs the simplified processing of input 
signals ( RBV and MSS signals ) and displays them onto 
the CRT for evaluating the image quality. 
At the same time, the image on the CRT is photographed 
on a 70 mm black-and-white film. 
c) HDDT recording/reproducing unit 
Recording/reproducing : SISO ( Serial In and Serial Out ) 
Recorded contents : RBV signals ( 20 tracks ), 
de MSS signals ( 10 tracks ), 
HK ( House-keeping ) signals 
C1 track ), 
Time signals ( 1 track ). 
3.4 Data processing subsystem 
The Data processing subsystem consists of the Data processor, 
the CCT ( computer-compatible tape ) recording/reproducing unit 
and the Film image producer. 
This subsystem is for calibrating radiometer sensitivity and making 
correction of image distortion due to satellite attitude changes. 
The input data are fed from the HDDT recording/reproducing unit. 
The CCT is produced through the CCT recording/reproducing unit, 
while an exposed 70 mm film ( latent image ) is produced through 
the Film producer. The following are major functions and speci- 
e fications of this subystem : 
e 
C" 
a) Data processor 
Processing accuracy : 
Radiometric error" : 1/64 of maximum input value 
Geometric error ** : Approx. 80m ( rms value) 
( Note ) * Ground truth is used. 
** Ground control point is used. 
Processing capability : Approx. 10 scenes a day 
b) CCT recording/reproducing unit 
Output : CCT ( 1/2 inch width ) 
-7- 
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