Processor is based on a 32-digit signal processor TS-21020 with the floating point and a toggle frequency of 16 MHz.
Memory including star catalog.
For Program
640 Kbytes
For Data
512 Kbytes
The processors unit controlling tracker operation is implemented on a gate matrix with 5,000 gates.
There is a 12 digit video signal ADC at the processor input.
Data Exchange is supported via the back up interface MIL STD 1553-B.
The Processors capacity makes it possible to use it for other task solution in the background mode.
ONBOARD STAR CATALOG
Star’s equatorial coordinates
Total number of stars
8,500
Maximum star magnitude
+8.5
Number of catalog sectors
642
Maximum number of stars in sector
25
Time of browsing all sectors
(Without prior data about orientation)
30 seconds
DESTINATION, DESIGN AND OPERATION PRINCIPLE
VF STC 1 has been designed for the s/c attitude determination in the onboard star catalog coordinate system. It includes a digital TV camera with a processor.
The VF STC 1 lens projects the starry sky image onto the CCD array.
This image analysis includes:
Localization of the registered images of light sources in the processors image buffer (image buffer capacity is 2048 pixels) and calculation of their energy centers position on CCD array.
Identification of the registered stars with the cataloged objects by angular distances between them.
Determination of the s/c attitude in the catalog star’s coordinate system.
Realiability
Lifetime
15 years
Number of ON/OFF cycles
≥10,000
Number of the protection cover >10,000
openings/closings.
≥10,000
Probability of failure-free operation
during a 100 hour session
At the beginning of life
≥0.99995
At the end of life
>0.975
Maximum storage time
At least 20 years
Radiation stability of the components and materials used makes it possible to apply the modified star coordinate determination unit into geostationary and high apogee orbits.
ILLUMINATION CONDITIONS
Maximum star magnitude
+8.5
Registered with an exposure of 0.5 sec.
Coefficient of the lateral
≥8x109
Solar illumination attenuation
By a system “lens + baffle”
