Figure 1. The DLR-TUBSAT prior to launch

TUBSAT stands for Technical University of Berlin Satellite program. A total of six satellites are in polar orbit. The DLR-TUBSAT satellite carry 3 cameras in the visible wavelength range (See figure 1). The satellite is gyro stabilized and is able to track objects of interest on the ground. The altitude is 700 km and the speed is 25 Mack. With the 1m Telescope the DLR-TUBSAT can obtain 6 m spatial resolution, and it is able to track of an target object for about 2 minutes. The satellite is commanded by using a regular VHF/UHF antenna on ground level. The images are down loaded through the S-band at 2.208 GHz with a bandwidth of 8 MHz. The power of the S-band Transmitter is 5 Watts.

The DLR-TUBSAT frequencies are:
        436,075 MHz 12-50 kHZ bandwidth
VHF        143,075 MHz          
S-Band     2,208 GHz w/ 8 MHz bandwidth; 5 Watt; 70 deg. field of view.


1 25757U 99029B   01177.33774514  .00000188  00000-0  60141-4 0  8346
2 25757  98.3946 281.3415 0016333  65.5053 294.7842 14.49931933110409

The data from the S-band transmitter is received by the Svaltrack antenna, and a Satreciever converts the data to regular TV format. The images are then saved by a regular video recorder. The signal is BPSK, S-Band signal with veterbi coded data in ESA standard.

Signal Demodulation:
RF-Frequncy: 2208 MHz
IF- Bandwidth: 1,5 MHz
Video Bandwidth: 0,75 MHz
Demodulator Type: BPSK

Bitrate: 500 kbps
In-Coding: NRZL

Veterbi Decoder
Soft or Hard

Pattern (SyncWord): 1A CF FC 1D
Frame Length: 32 bit
WordLength: 8 bit
FrameLenght 1042 words