Originally Posted by
B Fraser
Precisely. Left with low plus right with height only works up to around 2,000 feet at best. Remember your met exams and the geostrophic wind ? Plus you need someone to work the burners and keep an eye on the GPS. Johnny Chinaman seemed not to have included either.
In any case, I found it only worked 70% of the time.
I believe that passive navigation has advanced a great deal in recent years. In particular, look at the (claimed) capabilities of the Aerostar stratospheric balloons. Indeed, they have been awarded a number of DoD contracts in recent years. I'm sure that China has been looking at similar capabilities.