I brought this up because I haven't seen any definitive info on this from DJI, other than users opinions which I value greatly and users posts similar to that shown below.
I fully understand mapping, GPS and geographic coordinates and how they are used for navigation. My career of 25-years was in civil engineering specializing in Geographic Information Systems (GIS), terrain mapping and computer 3D modeling/animation so I take your point and fully understand it.
However based on the vast amount of pertinent data that is constantly provided by the IMU, Barometer and Compass and used by the Spark it seems possible the Spark could calculate a vector from its current coordinate, when/where GPS was lost, to the RTH (point of take off) coordinate that is stored in the Spark and using the onboard tools/data perform an RTH.
It sure seems the numbers are there that are needed to fly home relatively safely and I would really like to know if the Spark actually uses them to RTH as I have seen people claim in posts.
Great discussion, thanks for your time!
This post was in this thread, I have seen others that made me wonder if the Spark actually uses that data to RTH without GPS support:
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