Here, PSF(x) : Point spread function (normalized). 
Ib ='1(-0) = RBb>+:"CCP count'of the’ black part of the 
airphoto signal. 
Iw = I(+o ) = Rw : CCT count of the white part of the 
airphoto signal. 
Point spread function can be calculated from I(x) 
PSF(x) = ILI eder (35 (5-4) 
Here, I(x), Ip and EB: ean obtain from CC eurve, i.e, PSF'can 
calculate from only observed image data. 
6. A constraint condition formula 
  
As for flying direction, PSF is broadened by the moving of the 
satellite through the accumulation as mentioned in section 2. A 
constraint condition formula on observed image I(x) will be 
derived. The effect of moving is expressed as follow. 
PSF (x) =f 20/2 PSFO(x!') dx! (6-1) 
x-b/2 
Here, PSFO(x) : PSF, assuming the sensor dose not move. 
Differentiating and using PSFO(x)—0 (x—-oo), PSFO(x) can 
calculate from PSF(x) 
oO 
PSFO(x) z7X.:-- PSF(x-b/2-j*b) (6-2) 
j=0 dx 
Using PSF0O(x)—0 (x >+wæ), 
+ co d 
LX. Qe PSR(eg D) = 4 (6-3) 
j=-c 
As |(a/ax)PSF(x)| —0 (|x|—w ), (6-3) can be written in finite 
expression. 
+m d 
HESS dx PSF(x*j*b) = 0 (6-4) 
j=-m 
Here, m and x are supposed m>>b and x<<m. 
Substituting (5-4) into (6-4) and integrating twice, 
+m 
X IGeq*b)s gtx +B (6-5) 
j= 
Here, A and B are integration constant. 
Subtracting (6-5) from (6-5) substituted x+1 in x, value of 
constant À can be calculated as À = I(x+(m+1)*b) - I(x-n*b) = 
Iw-Ib. So, (6-5) is expressed, 
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