r00t.cz

First Iranian military satellite

Signal modulation

Data

Bursts are scrambled using standard 9k6 packet regenerative scrambler. Most of the burst is filled with 010101010... pattern, data are only in the middle:

Data are formatted according to the AX.25 packet radio standard, including SPACE and EARTH callsigns, nothing unusual or interesting here... was hoping for something more original. It will likely be possible to figure out meaning of some of values, like time, voltages, maybe GNSS position.

Example data frame:

fm SPACE to EARTH ctl UI^ pid F0  HEX
424200EE4A3F2CAE49A92ED14AB37842F4F61AB6FF9514041B001318271000000000
0000023C023C023C003473DAF8C6067DEAE70926FC9900000000F92F000002130000
0000028E000000C8FF3800C800010001000100000000000000000001176E094A0303
E2155800D720C1080000000000000000D62C0D000000C1021F00002B000015170241
0100410000410001901814530200A13134D8D5000FF60FFE2005FA1B1904FB080706
002828FEFBF9FD000000004F2A3800200000010207D8000100000000000000000102
0000576000000000000000000008ED80000004170000040F02350000000000EC004E

14041B001318 bytes above decode into timestamp: 20-04-27 00:19:24 (time of receipt of above packet)