Cute-1.7 - FM packets all over the world

Hiroki Ashida provides an update on the Cute-1.7 Amateur Radio CubeSat launched at the end of April.

I'm Hiroki Ashida at Tokyo Institute of Technology (JQ1YCZ) and I'd like to inform you about our satellite's operation which starts very soon.

We're preparing for a long-run (continuous 12 hour) of the APD (avalanche photo-diode) carried on Cute1.7 + APD II, as a radiation monitor of low-energy (E> 10 keV) particles trapped in the LEO (low Earth orbit).

While the APD is operating, the status packet of APD is transmitted every 16 seconds (TBD). The observation will start at 10:40, May 21 (UTC) and the APD will be turned off on 22:40, May 21(UTC). So the APD packet can be received everywhere in the world!

This is the first time that Cute-1.7 + APD II transmits its FM packet around the globe.

Though the observation data will be stored in FRAMs, we'd like to know a real-time status of the APD during the observation. Your kind reports will be highly appreciated.

FM packets are transmitted on 437.475 MHz and packet formats are available in the following web-page. http://lss.mes.titech.ac.jp/ssp/cute1.7/
fm_mode_apd_e.html

4A-51-31-59-54-43-3E-4A-51-31-59-43-5A-3A-D0-30-77-B8-03-16-99
For example, according to an above APD status packet we can obtain informations as;

4A-51-31-59-54-43-3E-4A-51-31-59-43-5A-3A : Header(JQ1YTC>JQ1YCZ)

D0 : APD Packet ID (Fixed)
30 : Status Code
    APD Status : Operational
    HV Status : Set Value = Output Value
    Temp Correction : Active
    Data Mode : Counter Valid
    Detector : APD A
    APD Gain : Gain 30
    Threshold : 219mV
77 : Temperature
0x77 = 119 -> (119/255)*91.712-48.569 = -5.7 [degC]
B8 : High Voltage
0xB8 = 184 -> (184/255)*396.5 = 286 [V]
03-16-99 : Counter
0x1699 = 5785 -> 5785 * 2^3 = 46280

Latest TLE from NORAD is;

Cute-1.7 + APD II

1 32785U 08021C 08140.34460534 +.00000335 +00000-0 +49764-4 0 00590

2 32785 097.9939 200.3316 0014139 226.7351 133.2682 14.81357711003132

Best Regards,

Hiroki Ashida

Cute-1.7 + APD II
http://lss.mes.titech.ac.jp/ssp/cute1.7/index_e.html

Hiroki Ashida <hiroki@lss.mes.titech.ac.jp>
Laboratory for Space Systems
Department of Mechano-Aerospace Engineering
Tokyo Institute of Technology
TEL/FAX : +81-3-5734-2644
Room 554, Ishikawadai 1st Bldg, Tokyo Institute of Technology
2-12-1 O-okayama, Meguro-ku, Tokyo, Japan