FITSAT-1 – Full telemetry decode achieved.

Had an excellent FITSAT-1 pass last night, successfully received nearly three full frames of CW telemetry.

The image above (from the heavens-above.com prediction site) shows a similar pass and illustrates the reception window which is just less than 8 minutes. Each frame of telemetry takes around 2.5 minutes to receive, so I was extremely happy with the results.

Again I recorded the pass using SDR-Radio and played back the doppler corrected IQ file later decoding with the MRP40 program, hear is a small video demonstrating the decoding process.

and this was the resulting telemetry data when run through the analyser program (see previous post).

---------------------------------------
FITSAT-1 NIWAKA Downlink CW Code
---------------------------------------
Input Data------------------
S1 :f00501bb
S2 :88db0101
S3 :02000102
S4 :1e20201f
S5 :1a12aae7
-------S1------
S-mater of 437MHz RX :4.69[V]
Total Voltage of Solar cells :0.1[V]
Total Current of Solar Cells :0[mA]
Voltage of single cell battery :3.65[V]
-------S2------
Current of single cell battery :1054.69[mA]
Voltage of 3 series battery :12.83[V]
Current of 3 series battery :0[mA]
Voltage of 2.5V reference :0.02[V]
-------S3------
Voltage of Solar cell + X :0.07[V]
Voltage of Solar cell + Y :0[V]
Voltage of Solar cell - X :0.04[V]
Voltage of Solar cell - Y :0.07[V]
-------S4------
Temperature of 3 series battery   :2.73[℃]
Temperature of single cell battery  :6.25[℃]
Temperature of +Z side   :6.25[℃]
Temperature of –Z side   :4.49[℃]
-------S5------
S-meter of 1.2GHz RX :0.46[V]
------Timestamp-----
14day 3hour 49min 59sec

I have also uploaded a better recording of the audio.

FITSAT-1 CW Telemetry by nerdsville

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 :*
——-S1——
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]
——-S2——
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]
——-S3——
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]
——-S4——
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[℃]
——-S5——
S-meter of 1.2GHz RX :No Data
Timestamp :No Data