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meters are read in via a universal keyboard; in addition, a small optical 
reader printer may be used to record these parameters for control pur- 
poses. A motor-driven filter wheel permits selection of one of the seven 
spectral channels, even during flight. The lens aperture can be varied 
during flight and adjusted to the light conditions and to the filter, 
depending on the signal amplitude indicated on the oscilloscope. 
The current filter and aperture settings are indicated constantly by 
lamps. The main characteristics of the apparatus are as follows: 
Sensor Type: Fairchild, CCD 121 
Number of Image Points (Pixel): 1728 
Pixel Interval: 13 jp 
Type of Lens: Leitz ELMARIT-R, 1:2,8/f=24 mm 
Image Angle: 50° 
Line Frequency: 80 Hz (fixed setting) 
Velocity /Hight Ratio: 1:23 
Gray Shading Resolution: 9 Bits $ 256 steps 
Bit Rate: 1.1 MBit/s 
Spectral Channels: 0,45 p - 1,0 p (without filter, total spectral, 
range of sensor) 
0,47 p'- 0,530 p AR - 0,005 u 
0,535 p - 0,585 n AA = 0,050 u 
0,580 p - 0,630 p AÀ -0,050y 
0,640 u - 0,685 y AA = 0,085 p 
0,675 u - 0,730 p AR = 0,055 y 
0,75 u- 45 y AÀ = 0,25 m 
. Image Date Storage and Reproduction 
The analogue image signals generated in series by the sensor are conver- 
ted, in the first instance, to a respectively parallel 8 bits word. Inter- 
face electronics is used to convert these digital NRZ (= Non-return to 
zerro) words to a serial "bi-phase" modulated bit stream in order to 
record them on an HDDT. For performance of this task, the DFVLR, Ober- 
pfaffenhofen provided the airworthy HDDT magnetic tape, Ampex AR 1700