From: utzoo!decvax!harpo!eagle!karn
Newsgroups: net.ham-radio,net.space
Title: UoSAT Telemetry Equations
Article-I.D.: eagle.932
Posted: Mon May  9 15:50:38 1983
Received: Tue May 17 23:43:01 1983

The following is a recent set of telemetry decoding formulas for the
UoSAT-OSCAR-9 satellite, courtesy of the UoSAT group at the University
of Surrey, England.

    Telemetry sensor allocation:
    ---------------------------            update: 26 Apr 1983

Channel        Parameter                          Cal. Equation
*******        *********                          *************

00 Secondary S/C computer (F100L)      1.2N mA  (0.125A <I< 1A)
01 Solar array current  +X             200 + 1.12N mA
02 Battery half voltage                N/100 *(1.01)
03 Radiation detector A O/P            40N *(1.04) Counts/S
04 Radiation detector B O/P            40N *(1.04) Counts/S
05 Magnetometer expt. HY-coarse        INT(Nyc/63.5+0.689)*8054-Fy
06 Magnetometer expt. HX-coarse        INT(Nxc/63.5+0.689)*8103-Fx
07 Magnetometer expt. HZ-coarse        -INT(Nzc/63.5+0.689)*8009+Fz
08 Battery pack-A temperature          (474-N)/5 *(1.01) Degrees C
09 Spacecraft facet temperature +X     (474-N)/5 *(1.01) Degrees C
10 Visual display expt. CCD current    1.2*(N-30) mA    (0.15A <I< 1A)
11 Solar array current  -Y             200 + 1.12N mA
12 2.4 GHz beacon expt. power O/P      (N-145)*0.45 mW
13 Radiation expt. EHT volts           N volts
14 Radiation detectors expt. current   (N+20)/8 *(0.983) mA
15 Magnetometer expt. HY-fine          Fy=18.55*(Nfy-495.7) See Ch 05
16 Magnetometer expt. HX-fine          Fx=18.53*(Nfx-496.45) See Ch 06
17 Magnetometer expt. HZ-fine          Fz=18.34*(Nfz-493.55) See Ch 07
18 Battery pack-B temperature          (474-N)/5 *(1.01) Degrees C
19 Spacecraft facet temperature -X     (474-N)/5 *(1.01) Degrees C
20 Spacecraft computer current         1.2*(N-25) mA    (0.125A <I< 1A)
21 Solar array current  -X             200 + 1.12N mA
22 Battery / BCR    +14V bus           N/50 *(1.056)
23 Sun sensor +Z axis                  N/200 *(1.01)
24 10.4 GHz beacon expt. current       (N-40)/4 * 0.97
25 Magnetometer expt. temperature      (467-N)/6.85 Degrees C
26 Magnetometer expt. current          (N/8)*0.9945
27 Telecommand receiver current        (N-16)/8 *(0.952) mA
28 Radiation expt.  temperature +X1    (474-N)/5 *(1.01) Degrees C
29 Spacecraft facet temperature -Y     (474-N)/5 *(1.01) Degrees C
30 Battery charge current              2.9N mA
31 Solar array current  +Y             200 + 1.12N mA
32 Power conditioning module +10V      N/60 *(0.93)
33 Telemetry system current            (N-16)/30 *(1.084) mA
34 2.4 GHz beacon expt. current        0.4*(N-11) *(1.072) mA
35 145 MHz data beacon power O/P       (N-82)*1.67
36 145 MHz data beacon current         (N-7)/4 *1.014
37 145 MHz data beacon temperature     (474-N)/5 *(1.01) Degrees C
38 Pri.S/C computer temperature -X1    (474-N)/5 *(1.01) Degrees C
39 Spacecraft facet temperature +Y     (474-N)/5 *(1.01) Degrees C
40 +14V line current                   2.86N mA
41 +5V line current                    1.28(N-50) mA    (0.075A <I< 1A)
42 Power conditioning module +5V       2N/300 *(1.12)
43 Sun sensor -Z axis                  N/200 *(1.01)
44 HF beacons expt. current            (N-36)/3 *1.038 mA
45 435 MHz data beacon power O/P       (N-102)*1.792
46 435 MHz data beacon current         (N-34)/3 *1.053 mA
47 435 MHz beacon temperature          (474-N)/5 *(1.01) Degrees C
48 Sec.S/C computer temperature -Y1    (474-N)/5 *(1.01) Degrees C
49 Spacecraft facet temperature +Z     (474-N)/5 *(1.01) Degrees C
50 +10V line current                   3N mA
51 -10V line current                   1.3*(N-60) mA
52 Power conditioning module -10V      0.0158N - 0.0224'N' ('N'=Ch 32)
53 Navigation magnetometer Y-axis      (N-663.44)*183.486    (nT )
54 Navigation magnetometer Z-axis      -(N-336.55)*189.54   (nT )
55 Navigation magnetometer X-axis      -(N-496.5)*194.55    (nT )
56 Speech synthesiser current          (N-16)/10 *1.009 mA
57 CCD imager temperature              (474-N)/5 *(1.01) Degrees C
58 Telemetry system temperature +Y1    (474-N)/5 *(1.01) Degrees C
59 Spacecraft facet temperature -Z     (474-N)/5 *(1.01) Degrees C

The navigation magnetometer is subject to temperature drift which can
cause clipping of the output.
NOTE: The axis labelling now employed is right-handed for all sub-systems.





Status points                                '0' '1'
-------------                                -------
01     145 MHz general data beacon           off/on
02     435 MHz engineering data beacon       off/on
03     Primary Spacecraft computer           off/on
04     CCD camera module                     off/on
05     Radiation detector - A                off/on
06     Magnetometer expt.                    off/on
07     7 MHz beacon expt.                    off/on
08     14 MHz beacon expt.                   off/on
09     28 MHz beacon expt.                   off/on
10     21 MHz beacon expt.                   off/on
11     2.4 GHz beacon expt.                  off/on
12     10.47 GHz beacon expt.                off/on
13     145 MHz command RX                    Squelch 0= signal present
14     435 MHz command RX                    Squelch 0= signal present
15     Status calibrate
16     BCR status                            A/B
17     H.F. beacons   expt. synthesisers     off/on
18     Telecommand decoder status            ground/primary computer
19     Magnetorquer                          off/on
20     Primary S/C computer block load port  disable/enable
21     Secondary S/C computer data O/P       active/inactive
22     Secondary S/C computer clock          interrupt failure/clock OK
23     Secondary S/C computer processor      running/halted
24     Secondary S/C computer power-down     high/low power
25     14MHz H.F. beacon synthesiser lock    out/in
26     28MHz H.F. beacon synthesiser lock    OUT/IN
27     21MHz H.F. beacon synthesiser lock    OUT/IN
28     Radiation detector - B                off/on
29     Tip mass uncaging Confirmation        no/yes
30     Speech synthesiser power              off/on
31     Visual data display memory            off/on
32     Gravity gradient boom motor power     off/on
33     Secondary S/C computer power          off/on
34     HF beacons expt. power                off/on
35     Navigation magnetometer power         off/on
36     S/C computer memory error bit -1
37     S/C computer memory error bit -2
38     S/C computer memory error bit -3
39     Status calibrate
40     primary S/C computer data UART O/P    inactive/active
41     Gravity gradient boom motor           forward/reverse
42     Magnetorquer power                    forward/reverse
43     Magnetometer expt.                    measure/calibrate
44     Navigation magnetorquer               safe/arm
45     Gravity gradient boom motor           safe/arm