[ This information was forwarded by the W0RPK-AMSAT Bulletin Board Sytem ] [ operating on 515-961-3325 24-hours Ralph Wallio, W0RPK SYSOP ] Phase 3C Preliminary Telemetry Channel Allocations and Estimated Equations January 1988 Vern Riportella, WA2LQQ Telemetry Function Typical Equation Units Channel (Subject to final cal.) ----------------------------------------------------------------------------- 00 Solar panel out and BCR input voltage n*150 mV 01 70 cm xmtr average power output (253-n)^2/2000 W 02 70 cm rcvr temperature (n-127)/1.82 C 03 (Reserved) - 04 BCR output and main battery voltage (n-10)*75 mV 05 (Special Purpose) xxxxxxxxxxxx - 06 2 m xmtr power amplifier temperature (n-127)/1.82 C 07 +14 volt rail current to xponder (n-15)*20.64 mA 08 +10 volt regulator voltage (n-12)*50 mV 09 Helium tank high pressure (TBD) Bar 0A IHU temperature (n-127)/1.82 C 0B +14 volt rail current to magnetorquers - and antenna relay (n-15)*4.128 mA 0C BCR oscillator #1 status 0=Off; N>10=On - 0D He tank low side pressure control voltage (TBD) - 0E BCR temperature (n-127)/1.82 C 0F +10 volt regulator current (n-15)*4.128 mA 10 BCR oscillator #2 status 0=Off; N>10=On - 11 N2O2 tank pressure (TBD) Bar 12 SEU temperature (n-127)/1.82 C 13 Battery charge current (n-15)*10.32 mA 14 Top (+Z) photocell sun sensor (See note below) - 15 Motor valve status (TBD) - 16 Auxillary battery #1 temperature (n-127)/1.82 C 17 Active BCR ouput current (n-15)*20.64 mA 18 Bottom (-Z) photocell sensor (See note below) - 19 S-Band xmtr power output (TBD) mW 1A Auxillary battery #2 temperature (n-127)/1.82 C 1B Active BCR input current on 28 volt line (n-15)*10.32 mA 1C Spin rate {if n<139, r=(139-n)*0.8+20 rpm or {if n>=139 r=508/(n-116)-2 rpm 1D 24 cm rcvr AGC {if n<100 AGC=0 dB or {if n>=100 AGC=(n-100)^2/189 dB 1E Main battery temperature (n-127)/1.82 C 1F Solar panel #6 current (n-15)*4.128 mA 20 2m xmtr average power output (200-n)^2/2000 W 21 He tank temperature (n-127)/1.82 C 22 Solar panel #1 temperature (n-127)/1.82 C 23 Solar panel #5 current (n-15)*4.128 mA 24 70 cm rcvr AGC (n-83)^2/1000 dB 25 70 cm xmtr PA temperature (n-127)/1.82 C 26 Solar panel #3 temperature (n-127)/1.82 C 27 Solar panel #4 current (n-15)*4.128 mA 28 Special purpose xxxxxxxxxxxx - 29 24 cm rcvr temperature (n-127)/1.82 C 2A Solar panel #5 temperature (n-127)/1.82 C 2B Solar panel #3 current (n-15)*4.128 mA 2C +14 volt regulator voltage (n-10)*61.5 mV 2D RUDAK temperature (n-127)/1.82 C 2E Top (+Z) skin temperature of arm #1 (n-127)/1.82 C 2F Solar panel #2 current (n-15)*4.128 mA 30 Mode B transponder +9 V supply voltage (n-10)*50 mV 31 Wall temperature in arm #2 (n-127)/1.82 C 32 Bottom (-Z) skin temperature of arm #1 (n-127)/1.82 C 33 Solar panel #1 current (n-15)*4.128 mA 34 Special purpose xxxxxxxxxxxx - 35 Wall temperature in arm #1 (n-127)/1.82 C 36 N2O4 tank temperature (n-127)/1.82 C 37 Reserved - 38 Auxillary battery voltage (n-10)*75 mV 39 Mode S transponder temperature (n-127)/1.82 C 3A +Z platform temperature (SERI experiment) (n-127)/1.82 C 3B Reserved - 3C Mode L transponder +9 V supply voltage (n-10)*50 mV 3D AZ-50 tank temperature (n-127)/1.82 C 3E Nutation damper temperature (n-127)/1.82 C 3F Reserved ------------------------------------------------------------------------------ NOTES: The equation values are preliminary estimates ONLY. IHU = Integrated Housekeeping Unit; the computer BCR = Battery Charge Regulator He = Helium SEU = Sensor Electronics Unit N2O4 is nitrogen tetroxide; the propellant oxidizer UDMH is unsymmetrical di-methyl hydrazine; the propellant fuel Notes regarding channels 14 and 18: These two sensors detect sunlight on the top (+Z) surface and the bottom (-Z) surface of the spacecraft. The provide only a rough indication of sun position and are used to resolve ambiguity in the readings from the sun sensors. When in full sunlight, a count of 65 will result. A count of about 10 is background noise only. The sun is declared present when the count exceeds 20. The main spacecraft solar cell arrays receive maximum illumination when the sun is perpendicular to (normal to) the spin axis (Z-axis). When this condition exists, both the +Z and -Z detectors will yield background readings (10) only. A count of 20 or greater on either indicates misalignment. The higher the count, the greater the misalignment of the spacecraft with respect to the sun angle (beta angle). Source: W3GEY 15Apr86; ASR 93, 31Dec84; ZL1AOX 27Jan88.