A nine prism array, pointing down to an instrument measuring up the mountain.?ÿ
I spent a lot of time doing the same, of course not at 29,000'.?ÿ
We would raise a 4' tall electric conduit pipe, set an orange painted gallon ice cream bucket over it with center cut holes for the pipe and set a prism array in the pipe. Sometimes up to 12 prisms-4 sets of triples. Then measure to it from up to 30,000' away. The ice cream bucket would really shine. Verticals taken to the 4' mark. All with a T2 and HP distance meter.?ÿ
The reason here would be some kind of check to the gravity measurements I assume. A lot of equipment to carry to the top of Everest.?ÿ
Gravity would be hard to do on the ground due to the snow load, movement,lack of heat(L&R meters and Scintrex CG-5s wouldn't have enough power to stay warm) nor would it be feasible to load up a MicroG A10 or FG-5due to the same conditions. Better and safer to just fly it and stay warm.?ÿ IMHO.?ÿ ?????ÿ