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Starshine telemetry #2



I calculated the telemetry data from Starshine, how to convert from
raw data to engineering units.

[145.825MHz, 9600bps FSK]
[10-Oct-01  07:21:07z] (UI C)
STRSHN>APF302:>de N7YTK.0C00
29D3 0000 29C6 A40E 845A 0281 FC75
1A96 84F0 58BF 7706 9402 028C FC8B
65D7 277C 3D21 298B A2FA 0271 FC45
2802 900C A106 9395 854E 0286 FC65
D294 829B 021E 6441 5400 0279 FC22
6D86 4185 A549 6486 00B2 026B FC90


Phillip Jenkins [Phil.Jenkins@grc.nasa.gov] wrote
at 14:08:51 -0400, 12 Oct 2001,

> It looks like we need to add a few more instructions to the web page
> on how to convert raw data to engineering units. It is my fault that
> it is not on the web site yet.  Here is the formula for converting
> the raw signal to volts:
>
>    Volts = (CH11 - ValOff)/(CalVal - ValOff)) * Vref/GAIN
>                                       - ((Vref/GAIN ) * Offset/100)
>
> Ch11 CH12 CH13 CH14 CH15 ValOff CalVal
> 29D3 0000 29C6 A40E 845A 0281 FC75


Using my telemetry packet, first I convert all HEX to DEC.
Then,

    CH 11  = 29D3(hex) = 10707(dec)
    ValOff = 0281(hex) =   641(dec)
    CalVal = FC75(hex) = 64629(dec)
    GAIN for CH11 = 16
    Offset = 16.6666
    Vref   = 2.493

    Therefore, Volts = (10707-641)/(64629-641)*2.493/16
                               - ((2.493/16)*16.666/100)
                     = 0.001457 [Volts]
                     = 1.457 [mV]

    which is in the "Range(mV) -2.5/40" = -0.0625.

He says also,
> Channels 11,12 and 13 malfunctioned before launch and are not valid.

Refer to the URL for more information,

 http://epulation.com/starshine/starshine3/

----------------------------------------------
Name : JE9PEL/Mineo Wakita, JAMSAT member
Mail : ei7m-wkt@asahi-net.or.jp
URL  : http://www.ne.jp/asahi/hamradio/je9pel/
QTH  : Yokohama Japan, GL:PM95TJ
Date : Oct 13, 2001
----------------------------------------------


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