How is the location data in CAM messages calculated? Can It be configured to use GPS2 instead of GPS1?

Hi, I was running some tests using a secondary GPS and wanted to geotag the images using the secondary GPS. I found that the CAM message in the logs contains the location data calculated using the acceleration data and the Previous GPS Coordinate. How is this calculated? Can I utilise the GPS2 data to calculate the same instead of GPS1 Data?

As a side note, can I utilise Camera Shutte lag in this calculation?

Got the same question!

Same question here too…
Were you able to find out? Also, I understand you’re using piksi as GPS2… For any reason, if you lose RTK fix/float, does your GPS2 stop logging?

Hi arthur. This was over a year ago from when i was trying to use piksi for my plane. I’ve learned that on using GPS_AUTO_SWITCH, you can control which GPS is used for navigation and subsequently, in CAM messages.

http://ardupilot.org/plane/docs/parameters.html#gps-auto-switch-automatic-switchover-setting

On a side note, Over multiple tests, I concluded that I could not achieve a reliable fix solution in piksi, and that if i ever lose telemetry, I’ll end up losing my solution too.

Ive switched to using a PPK setup that uses emlid reach -

https://emlid.com/reach/

I’ve found it to be far more reliable and convenient. I can post-process the data with more control.

Hope that helps,

Nihal

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