Telemetry decoding

This evening we did some telemetry decoding.

April 1, 2013 17:50 UTC

First CubeSat we gave a try was STRaND-1, but it wasn’t sending any data this evening (April 1, 2013 17:50 UTC). When I looked at the Satblog from DK3WN it seems that STRaND-1 wasn’t heard the whole day. Lets hope noting is wrong with the CubeSat.

April 1, 2013 18:05 UTC

RAX-2 is sending telemetry loud and clear, and the combination FUNcube Dongle Pro+, Orbitron and SDR# are doing a great job in controlling Doppler thanks to a great Doppler control plugin that can be part of SDR#.

RAX-2 SDRSharp

RAX-2 is sending every 20s a 9k6 data burst that can be decoded with the decode software from Mike DK3WN. During this pass I received over 60 packets and in the below image you can see the results.

RAX-2 TLM 01-04-2013 18:05 UTC

Here is an example of a KISS frame that is received from RAX-2, nice to see the error that RAX-2 is using RAX-1 as Call.

[254 Bytes KISS Frame (without CRC)]
ctrl: 3   PID: F0 {UI}   235 Payload Bytes
from RAX-1 to CQ: 
   1 > AB CD 00 00 06 00 03 EB 00 6E 76 33 CB 59 51 58 CB 59 51 00 
  21 > 00 00 00 90 00 FF FF 31 05 99 00 95 09 16 00 03 00 4C 00 9E 
  41 > 00 15 00 29 00 00 00 19 00 00 00 80 00 77 02 6E 07 02 00 FF 
  61 > FF 08 00 00 00 CD 00 6E 07 41 07 00 00 00 00 35 00 93 00 11 
  81 > 00 3C 01 33 93 E7 C2 05 00 00 00 00 00 D5 39 00 00 00 00 BD 
 101 > FF 47 00 84 FE 10 00 13 00 A9 00 58 00 00 00 00 00 25 00 E1 
 121 > FF 15 00 AE FE 04 01 75 04 B4 08 F0 0A AF 02 90 05 0C 00 00 
 141 > 00 08 00 5B 06 02 00 00 00 07 00 EF 05 01 0E 7E 07 83 08 2E 
 161 > 06 91 02 AF 01 D1 02 36 06 00 00 C6 09 25 00 84 06 83 38 FF 
 181 > FF FF C7 0F D2 12 5A 59 59 5C 5C 5C 5B 9B CE 42 00 00 9F 51 
 201 > FF 44 66 FF 9E 5B CE C8 C8 3F A0 00 00 00 41 9F 00 00 00 FF 
 221 > FF FF D2 07 18 FF FF FF FF 4F 08 5E F1 68 DD

April 1, 2013 19:02 UTC

MASAT-1 sends a two tone signal

MASAT-1 Audio Spectrum

This signal can be decoded with the telemetry software that is available on MASAT-1 website. After that you can use the log file with a decoder program from DK3WN and this produces the following output.

MASAT-1 TLM 01-04-2013 19:02 UTC

Here is an example of the data that is send by MASAT-1

PACKET 03 EC 03 19 6C 20 CE 00 AE 55 00 00 42 55 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c71bc513453b2f0810625751f5236f4df7a11078 1364842925809

When you want to experiment with receiving telemetry, take a look at my soundcard page and give it a try.

ElaNa cubesat ID’s published

Thanks to the satblog from DK3WN, I saw that Space-Track.com published now the ID’s for the last cubesat launch.

DICE 1
1 37851U 11061B   11335.98213095 +.00005465 +00000-0 +44960-3 0 00372
2 37851 101.7084 281.3727 0254523 194.8404 164.5233 14.77965880005103
DICE 2
1 37852U 11061C   11335.98154484 +.00005944 +00000-0 +48768-3 0 00438
2 37852 101.7074 281.3718 0254311 194.8534 164.5099 14.78016598005106
RAX-2
1 37853U 11061D   11336.52203229  .00005951  00000-0  48803-3 0   339
2 37853 101.7000 282.1398 0254011 193.6021 165.8244 14.78071279  5174
AUBIESAT-1
1 37854U 11061E   11335.84070964  .00006374  00000-0  51608-3 0   340
2 37854 101.7036 281.1694 0255290 195.0285 164.3221 14.78269655  5064
M-CUBED/EXP-1 PRIME
1 37855U 11061F   11335.84128847  .00006165  00000-0  49988-3 0   329
2 37855 101.7072 281.1754 0255380 195.0474 164.3035 14.78230731  5068

Any idea why M-Cubed and E1P use the same Catalog number? Are we missing an International Designator?

Update: Dec 6, 2011

DK3WN posted on his satblog: RF Confirmation –  M-Cubed attached to E1P

Spectrum M-Cubed-E1P DK3DWN

RAX-2 is OBJECT E

A good explanation from DK3WN on how to determine what TLE data belongs to what Satellite.

Based on the latest cubesat TLEs we have now three groups of objects (B+C+D, E, F+G). The first group are the 1U cubesats – they are only a few km apart. In 13 sec distance is RAX-2. I think F and G are the DICE sats.

Elena-III All TLE 02-11-2011

A simple way to determine the TLE, Take one beacon frequency – in this case 437.435 MHz (belongs to RAX-2). Then I calculated all the doppler frequencies for all objectes on a high 66 deg elevation pass. If the doppler = 0 then we have TCA. In this way you can calculate the distance between the TCA of each satellite.

Elena-III All TLE Doppler correction

You can see the 13 sec difference of RAX to to the first group (E1P, MCubed and AubieSat-1)

RAX-2 Zero 02112010 11:13UTC Pass

Take a look at the spectrogram – the horizontal yellow line is the center frequency of 437.345 MHz and the vertical one is the calculated time for RAX-2. And as chance would have it – we have a packet there. If you take the middle frequency of this 9k6 packet -> it all comes to one point.

Source: Satblog – DK3WN

E1P-U2 is Alive

During the second passage there where again signals from E1P-U2 and because we now switched to LSB modulation, we heard recognizable signals. These where decoded with the use of MixW and the Explorer-1 telemetry decoding software by G3VZV. We now know that there are two active satellites which were launched this morning. E1P-U2 Explorer-1 [PRIME] and RAX-2 both are received.

E1P Telemetry Data

Initial CubeSat kepler data

Initial Cubesat TLE data for AubieSat-1, E1P-U2, M-Cubed, RAX-2 and DICE

AubieSat-1
1 99994U 00000    11301.47661542 0.00000000  00000-0  00000-0 0  0004
2 99994 101.6484 233.3593 0253027 295.2632 199.6027 14.79026571000008
E1P-U2
1 99995U 00000    11301.47661542 0.00000000  00000-0  00000-0 0  0005
2 99995 101.6483 233.3593 0252986 295.2628 199.6029 14.79017909000003
M-Cubed
1 99996U 00000    11301.47661542 0.00000000  00000-0  00000-0 0  0006
2 99996 101.6483 233.3593 0252943 295.2624 199.6032 14.79009197000007
RAX-2
1 99997U 00000    11301.47777282 0.00000000  00000-0  00000-0 0  0006
2 99997 101.6434 233.3640 0249216 295.6962 205.2960 14.78420752000002
DICE-F
1 99998U 00000    11301.47893023 0.00000000  00000-0  00000-0 0  0009
2 99998 101.6485 233.3603 0247816 295.0284 212.1452 14.77853717000006
DICE-Y
1 99999U 00000    11301.47893023 0.00000000  00000-0  00000-0 0  0000
2 99999 101.6484 233.3604 0247744 295.0246 212.1487 14.77838475000007