£ i= Ded/Ax (1) 
Fig. 4 shows this relation with the parameter d. The most 
small photodiode size is about 7 um and usually 14 4m size 
photodiode elements are arranged in a linear array. So, two 
lines for 7 4m and 14 um are shown in the figure. Spatial 
resolution of telescope is limited by diffraction. The 
aperture of telescope M. wave length (A, and an \angular 
resolution Aw are connected as follows: 
AW = 1.22 Ag 
The limited ground resolution A Xp is D-Aw, then, we have, 
f - 1.22 AD/Axy, (2) 
Fig. 5 shows this relation provided that D is 38,140 km and 
2unissl.l Am. 
If 100 m ground resolution is required for the observing wave 
length 1.1 4m and photodiode aperture 14 um, then we can say 
from Fig. 4 and Fig. 5 that the focal length must be 5.35 m and 
the aperture of telescope 0.5 m at least. 
If 50 m ground resolution is required for the same wave length 
and -photodiode aperture, then 10.7 m focal length and 1 m 
minimum aperture are needed. 
2.3 Shape of correcting plate 
The shape of correcting plate of Schmidt telescope is given by 
following equations: 
  
7 = By: -i wy? 
k 
= 5 
128(n-1)f-(Fyo) 
: 2. 2 
B= fo = le] (3) 
64 (Fyo) 
Jo 1 
o 32(n-1) £3 
Here, k is a parameter which determine the radius of neutral 
zone (no power part between the convex and concave parts), and 
n:is.anindex. of glass: (cf. Fig. 6). The radius oficurvature 
of the primary mirror R is given by the equation: 
> 
k 
R= f + [£2 + ? (4) 
16 
  
As above mentioned the minimum aperture of telescope for 100 m 
ground resolution is 0.5 m, however this diameter is required 
TT