The first is a talk on differential GPS which is part of a collaboration between Ben Nizette at ANU and myself.
I've just released APM:Plane 2.78
This is a bug fix release for a number of important issues found in the 2.77 release.
The changes in this release are
Fixed sensor start-up on the APM1
I'm embarrassed to say that I didn't test the APM1 for the 2.77…