KODIAK STAR LAUNCH MONITORING TEAM PLAN (Draft 19 Sep 2001) --------------------------------------- (B.Bruninga, WB4APR) http://www.ew.usna.edu/pcsat.html Although Launch is from Kodiak, Alaska, most post launch data will be derived from dozens of amateur satellite monitoring stations around the world who will provide initial telemetry and monitoring data to the launch team. PCsat has no whole orbit telemetry storage on board. It is dependent on ground based internet linked capture and distribution of live telemetry to the command station in Annapolis not only during the initial phases, but throughout its life. For the initial post launch spacecraft on-orbit checkout, the Launch Monitoring Stations will fall into three categories: Packets detected by ear and noted as to exact times of receipt Packets copied to file and Emailed Packets injected live into the worldwide APRS internet system REPORTING: Telemetry data is shared among the launch team via live connection to the worldwide APRS Servers, or via Email. Stations connected to the servers can also communicate via Keyboard directly via APRS messages to the USNA W3ADO command station. The APRS servers are, in order of availability listed as follows: AHUBEAST.NET port 2023 APRTLM,SGATE:T#sss,111,222,333,444,555,11111111,00NN,0 PCSAT-11>APRTLM,SGATE:T#sss,111,222,333,444,555,11111111,00NN,0 Presumably all of the packet timers on PCsat will initialize at the same time, so the activity should be bunched around the minutes. Also the SAFE mode for PCsat has both transmitters cross connected so that every packet from either TNC will appear on both frequenceis. Thus only a single receiver is needed on either 145.825 or 144.39 to capture all telemetry. LISTENING to 9600 BAUD: A 1/2 sec 9600 baud packet is indistinguishible by ear from open squelch FM noise. The only way to detect it is by having your squelch set above threshold to quiet the speaker. Then any 9600 baud packet will sound like a brief open squelch. Please time the period and relative occurance of these relative to other packets. Due to the scheduling, most 9600 baud packets from PCsat will occur immediately adjacent to a 1200 baud packet and so may just sound like either a leading or trailing noise burst on the 1200 baud packet. The STARSHINE 9600 baud burst should be independent of these and should also occur 5 minutes or more in advance of PCsat on the second orbit. This is because Starshine is the last to separate after a significant second orbit altitude maneuver to lower it 300 km below the other satellites. Due to this lower altitude, Starshine will be going faster by about 5 minutes on the second orbit. Palmer Station and then South Africa will be the first to hear these packets and must be prepared to differentiate between the single 9600 baud Starshine packets and the grouped PCsat packets. SAPPHIRE: Sapphire has an initial Beacon mode using a simple CW dit-dit once a minute. The presence of these two bursts once a minute on 437.100 (+/- Doppler) will constitute proper separation. TIMING: Please initialize all TNC clocks to UTC. The Kenwoods built-in TNC's do not have clocks, so please keep a written log of time of receipt on the first orbit or so if possible. If your packets are injected LIVE into the internet stream no time stamp is required. STATION SETUP: MINIMUM STATION: The minimum station simply monitors all packets on 145.825 at 1200 baud. If all systems on PCsat are operational, all telemetry can be captured there. But it will take 12 minutes to get a complete set of system-B telemetry. TWO SYSTEMS: If two receivers and TNC's are available, the best setup will be to have one at 1200 baud and the other at 9600. Not only does this capture data from PCsat faster, it also is ready to capture data from Starshine on the second orbit. Since the two spacecraft and 3 TNC's share the same frequency, they will not overlap, so the RS-232 outputs of the two TNC's may be able to be dioded-ORed together into the same ASCII capture file. THREE SYSTEMS: If a third UHF receiver (no TNC) is available, a constant monitor on the Sapphire 437.100 downlink by ear should reveal the beacon dits from that spacecraft. ANTENNAS: None of these satellites have attitude control on these initial orbits, so the polarization will be random. PCsat does have cross polarized antennas for all uplinks and downlinks, but the other spacecraft downlinks are all linear. Power from all three are within 3 dB of each other and should have a few dB link margin. For comparison purposes, the packets from these birds should be on the order of 3 dB less than the existing downlink from the ISS on 145.800 (when it is on)... Use the ISS as a good means to test your station (and also serve the worldwide community by serving the downlink into the worldwide APRS system where it can be seen on http://www.ariss.net. An omni 2m antenna with minimal cable loss should be sufficient to capture most of the telemetry when the satellite is in view when the polarizations match. But due to the lack of polarization control, a beam will improve performance. For Sapphire on UHF, a short beam and/or preamp may be required to overcome cable loss. ALso, expect a -7 dB performance difference on 9600 baud. LONG TERM: As noted above, both PCsat, and Starshine represent a new breed of amateur satellite that presume a worldwide internet linked ground station network for capturing whole orbit data on 145.825. Many of the dozens of student CUBESATS scheduled for launch in May 2002 and the next two Starshines 4 and 5 tentativley scheduled for Nov 2002 will also use this technique. We hope that members of the Kodiak Star Launch Monitoring Team will consider assembling a permanent amateur satelltie monitoring station to serve this growing network of amateur satellites. de WB4APR Bob Bruninga PCSAT WEB PAGE: http://www.ew.usna.edu/pcsat