Wednesday, August 4, 2010

UI-View32 Meteor Mode

Hunting meteors with APRS is an interesting twist. Here's some info from the manual of UI-View32

UI-View32 Meteor Mode is a special mode in which the program can be used to transmit beacon frames very frequently. It is designed to be used for meteor scatter propagation tests.

Two different modes of operation are possible - "Interval" mode and "Burst" mode.
  • Interval Mode - A single beacon frame is transmitted at a specified time interval.

  • Burst Mode - Beacon frames are transmitted continuously for a period of seconds. You can specify how long the burst should be, and when you want it to start in terms of the number of seconds into each minute
  • Port - The port on which you wish to use Meteor Mode.

  • Unproto address - The address to which you want to send the beacon frames, including any digis. The destination address and digis should be separated with commas, do not used 'V' or 'VIA'. Examples - CQ would address the beacon frames to CQ, CQ,RELAY would address the beacons to CQ via RELAY.

  • Beacon - The text of the beacon you want to send. For meteor scatter use, the beacon should be as short as possible. The shortest beacon that can usefully be interpreted by APRS software is probably your IARU locator surrounded by square brackets, e.g. "[IO92XX]", and that is the beacon you are recommended to use.

NOTE - The following four automatic beacon input buttons cannot be used until you have input your latitude and longitude in Station Setup.
  • Grid - Automatically input a grid square beacon.

  • Grid-in-status - Automatically input an APRS "grid in status" format position beacon.

  • Posit - Automatically input a normal APRS position beacon.

  • Comp'd - Automatically input a compressed APRS position beacon.

  • Interval (only used in Interval mode) - The interval, in seconds, at which you wish to transmit a single beacon.

  • Start (only used in Burst mode) - The number of seconds into each minute at which you want the burst of beacon frames to start. You can specify more than one time, e.g. "0,30" would mean "start a burst at 0 seconds into each minute and another burst at 30 seconds into each minute". If you were conducting a trial with someone, then they might specify "15,45", so that your transmissions interleaved.

  • Duration (only used in Burst mode) - The length in seconds of each burst of frames. UI-View converts the specified duration into a number of frames to send. The calculation is accurate, but it makes two assumptions - (a) that you are using 1200 baud, and (b) that your TNC will transmit continuously when fed with a stream of frames. If your TNC releases the PTT every few frames (the TH-D7 appears to behave in this way.), then you will need to make allowances for it, because a specified duration of, say, 10 seconds, will result in an actual burst length of perhaps 15 seconds.

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