[amsat-bb] Cute-1.7 : FM Packets All Over the World !
hiroki at lss.mes.titech.ac.jp
Tue May 20 20:22:12 PDT 2008
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 12hour) 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 16seconds (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 437.475MHz and packet formats are
available in the following web-page.
For exapmle, according to an above APD status packet we can obtain
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
Cute-1.7 + APD II
Hiroki Ashida <hiroki at 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
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