Solutions to Tracking Payload Inconsistencies

The graphs below are the tracking results from two different flights with very different results in reporting consistency.

Here are some suggestions to minimize position reporting inconsistencies:

  • Make sure the tracking payload has a clear unostructed view of the sky
  • Test your Iridium tracking payload box ensure the container itself doesn’t interfere with with the Iridium modem communicating with the satellite
  • Fly the Iridium tracking payload on the top of the flight string in its own payload (see image below for suggested payload string configuration)
  • Do not fly any additional electronics within the Iridium tracking payload (GoPros, for example, seem to interfere when housed in the same payload as the tracking system)
  • Make sure the antennas are firmly attached and that the cables are not pinched or broken
  • Test your payload string to ensure other payloads are not interfering with the Iridium tracking payload

Iridium Light Configurations and their Meanings:

  • Power LED: lights up when power is applied to the 9602-LP and power-on button is pressed.
  • GPS LED: stays solid when there is a valid GPS position fix, blinks when there is 2D fix or using dead reckoning, and stays off when unable to obtain a position fix. Users have to watch closely for the LED since it can briefly stay on.
  • Iridium LED: stays solid when the Iridium signal strength is between 3–5 bars, blinks when the Iridium signal strength is between 1–2 bars, and stays off when the Iridium signal strength is at 0 bars. Since the Iridium modem is on over a short period during a location report, this LED will light up very briefly and users might not be able to see if not watched closely.
  • Status LED: when first entering Tracking Mode, the LED will not light up. This LED stays solid if the last SBD transmission had a valid GPS fix and successfully received by the gateway, blinks if the last SBD transmission was unsuccessfully sent or did not have a valid GPS fix but one was sent since the unit was turned on, and stays off if no SBD transmission with a valid GPS fix was sent to the gateway.
  • Emergency LED: lights up when the Emergency button is pressed or the Input S0 is activated.