home *** CD-ROM | disk | FTP | other *** search
-
- ---------
- SpaceNews
- ---------
-
- MONDAY JANUARY 9, 1989
-
- SpaceNews originates at KD2BD in Wall Township, NJ, and is available on
- packet radio bulletin board stations across the North America and around
- the world on the MTTBS telephone BBS at (201) 494-3649, the Unix UUCP
- USENET News Network, and also on WangNet.
-
- * MINI-TUTORIAL: DECODING OSCAR-9 TELEMETRY *
- ---------------------------------------------
- Decoding and analyzing OSCAR-9 telemetry is a easy for anyone having an
- HF receiver available to them. UoSAT-1 (OSCAR-9) currently transmits on
- 21.002 and 14.002 MHz using 10 WPM CW and 100 mW of transmitter power.
- OSCAR-9 also transmits on VHF, but uses 1200 baud ASCII for downlinking
- digital information to Amateur Radio ground stations around the world.
- I occasionally post news bulletins I receive from OSCAR-9 on VHF.
- Look for these bulletins on systems that also carry SpaceNews.
-
- OSCAR-9's telemetry contains 60 analog "channels" that are transmitted by
- it's on-board computer to ground stations. On HF, however, only the first
- 10 channels are downlinked by the HF beacon(s).
-
- The format for OSCAR-9's HF telemetry is: NNDDD, where NN is a two digit
- channel number, and DDD is a three digit telemetry value that is used as
- as the argument of a calibration equation. Calibration equations are used
- to convert the "raw" telemetry data values into real units like milli-
- amperes, volts degrees Celsius and nanoTeslas.
-
- An OSCAR-9 CW telemetry "frame" might look something like:
-
- AMSAT 00380 01370 02661 03481 04598 05046 06027 07056 08040 09033
-
- Notice that the channel numbers range from 00 to 09. The numbers following
- these numbers are the raw telemetry values that are substituted into the
- calibration equations for decoding the actual telemetry data.
-
- Each calibration equation was calculated to give the best "straight-line"
- fit to the actual measured performance of the telemetry sensor before
- launch.
-
- Equations for OSCAR-9's first ten analog telemetry channels are as follows:
-
- 00 : SECONDARY SPACECRAFT COMPUTER CURRENT : I = 1.2N (mA)
- 01 : SOLAR ARRAY CURRENT (+X FACET) : I = 200 + 1.12N (mA)
- 02 : BATTERY HALF VOLTAGE : V = N/100 * 1.01 (volts)
- 03 : RADIATION DETECTOR A OUTPUT : Count = 40N * (1.04)
- 04 : RADIATION DETECTOR B OUTPUT : Count = 40N * (1.04)
- 05 : MAGNETOMETER EXPERIMENT HX-COARSE : Bx = (129N - 64824) (nT)
- 06 : MAGNETOMETER EXPERIMENT HY-COARSE : By = (129N - 64433) (nT)
- 07 : MAGNETOMETER EXPERIMENT HZ-COARSE : Bz = (129N - 64072) (nT)
- 08 : BATTERY PACK-A TEMPERATURE : Temp = (474 - N)/5 * (1.01)
- (C)
- 09 : SPACECRAFT FACET TEMPERATURE : TEMP = (474 - N)/5 * (1.01)
- (C)
-
- Listen for OSCAR-9 from around 7:00 to 9:00 (AM & PM) local time each day.
- If you hear the spacecraft and decode the telemetry, send me a note, and
- I'll include your data in an upcoming SpaceNews issue.
-
- If you have a narrow-band FM receiver capable of receiving 145.825 MHz,
- you can try listening for OSCAR-9 on VHF also. On Thursday's you'll be able
- to hear OSCAR-9's "Digitalker" speak selected telemetry data in plain
- English (yes, you CAN hear non-human voices from space!).
-
- Good luck!
-
- * OSCAR-9 NEWS *
- ----------------
- UoSAT-OSCAR 9 Weekly Operating Schedule :
-
- TUE : Diary reload occurs. VHF-FM beacon is OFF the air.
- WED : CCD Video transmission - 1200 baud synchronous data.
- THU : Digitalker sends telemetry in English until 14:00 UTC.
- After 18:00, the Diary will transmit a sequence of TELEMETRY, BULLETIN
- and WOD using 1200 baud ASCII until next Tuesday, when a reload occurs.
-
- The 145.825 MHz NBFM General Data Beacon is ON the air according to
- the above schedule. In addition, the 14.002 and 21.002 MHz beacons
- are currently active sending Morse telemetry and A0 using 100 mW
- of power. The 2.4 GHz FM beacon is OFF the air.
-
- * FEEDBACK WELCOMED *
- ---------------------
- Feedback regarding SpaceNews can be directed to me (John) via the following
- paths:
-
- UUCP : ucbvax!rutgers!petsd!tsdiag!ka2qhd!kd2bd
- PACKET : KD2BD @ NN2Z
-
- * JOIN THE RANKS! *
- -------------------
- Amateur Satellite operations can be very educational, rewarding and fun,
- but in order to communicate through any one of our "OSCAR"s, you must first
- have an Amateur Radio license. For information on the requirements for
- earning an Amateur Radio license in the U.S., write:
-
- THE AMERICAN RADIO RELAY LEAGUE
- 225 MAIN STREET
- NEWINGTON, CONNECTICUT 06111
-
- * SOURCES *
- -----------
- Some of the news contained in this SpaceNews issue was obtained via
- OSCAR-9, OSCAR-11 and the KA2QHD and NN2Z PBBSs.
-
- * BID$ *
- --------
- SpaceNews is available for UNLIMITED distribution.
- Please use Bulletin ID: SPC90109 when posting this bulletin on packet radio
- BBSs that support bulletin IDs. Thank you.
-
- Note: The BID$ have changed to an eight character format for
- compatibility with new W0RLI PBBS software.
-
- * MESSAGES de KD2BD *
- ---------------------
- >> KY2N : Bob, the new, shorter BID$ are now in use.
- >> VE3LVQ : Alan, thanks for your interest in SpaceNews. I hope these
- "mini-tutorials" are of interest to you!
- >> N1CUI : Ward, I get in touch with you regarding distribution to
- Ridgefield, CT.
- >> ALL : Thanks for reading SpaceNews.
-
- >> SpaceNews is a production of KD2BD Software. All rights reversed. <<
-