Thursday, 18 October 2012

Well got 80% of a full FITSAT-1 Telemetry Frame

Earlier today I posted about my latest attempts at receiving the FITSAT-1 Cubesat, the reception hadn't proved too difficult however actually decoding the morse code was proving difficult!

Having another go with the MRP40 decode software and replaying a recorded IQ wave file from yesterday I successfully decoded 80% of a full telemetry frame!

I also found this interesting pdf file detailing the construction of FITSAT-1 and discovered the 437MHz transmitter is only 100mW. So we have a flying metal cube measuring just 10cm x 10cm x 10cm travelling at approximately 4.5 miles/sec roughly 270 miles above the earth, transmitting with just a fifth of the power of one of those PMR446 hand held walkie talkies that in my experience struggle to maintain a contact over a few hundred meters! Isn't technology wonderful?

FITSAT-1, TechEdSat and F-1 Cubesats after leaving the ISS
Anyhow this was the telemetry frame, as decoded using a PC program developed by one of the students on the FITSAT team.
FITSAT-1 NIWAKA Downlink CW Code
Input Data------------------
S1 :f01601ba
S2 :8dbd8181
S3 :20001820
S4 :1e202020
S5 :*
S-mater of 437MHz RX :4.69[V]
Total Voltage of Solar cells :0.43[V]
Total Current of Solar Cells :0[mA]
Voltage of single cell battery :3.63[V]
Current of single cell battery :93.75[mA]
Voltage of 3 series battery :11.07[V]
Current of 3 series battery :0[mA]
Voltage of 2.5V reference :2.52[V]
Voltage of Solar cell + X :1.13[V]
Voltage of Solar cell + Y :0[V]
Voltage of Solar cell - X :0.84[V]
Voltage of Solar cell - Y :1.13[V]
Temperature of 3 series battery   :2.73[℃]
Temperature of single cell battery  :6.25[℃]
Temperature of +Z side   :6.25[℃]
Temperature of –Z side   :6.25[℃]
S-meter of 1.2GHz RX :No Data
Timestamp :No Data

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