How headings are calculated

Does the unit have an inbuilt compass, or does it use the GPS data to track a heading? I’m just wondering, as the pilot and I were trying to figure out why there would be a 8-14 degree (obviously not a huge deal) heading discrepancy between the plane GPS and the Dekunu. If there is indeed it’s own compass inside, then perhaps a setting to manually compensate for compass variations for different locations, or to aggregate it based off of where the device is being used via GPS. Just a thought. Like I said, it’s not a huge deal because it’s all supplementary information, but if you’re wanting it to be spot on with it’s accuracy then maybe it’s something to look into.

Hey Joe,
heading is calculated using GPS rather than compass at this stage.
Do you recall if you were having patchy or consistent GPS signal?
View of the azimuth will allow for greater accuracy in recognition of current location and relative information such as heading/ground speed.
I’m keen to here if this is able to be reproduced using that same aircraft hardware.


Hey Simon, it’s actually been pretty consistently out for each jump that i’ve done with it, across all times of the day. The main runway that we use has a heading of 170, the Dekunu shows 184 as we take off, then generally it’s about 10-11 degrees off for each run in. When i’ve remembered to look at the number of satellites, i’ve always had a full gauge and 11 or 12 in the 2nd menu