Jeff Liebermann wrote:
> Radiosondes have two basic assumptions. The transmitter is always
> above the receiver and that antenna is always roughly vertically
> oriented.

Not so. The weather reporting radiosonde used in the 60s and 70s
aways drifted off to the horizon, driven by the prevailing wind.

The radio receiver was something like a ten foot diameter dish
under a plastic radome that tracked the radiosonde.

As i recall, they had a single tube transmitter that was frequency
modulated by the thermometer and air pressure was sensed by a
bellows that was mechanically connected to a rheostat that pulse
proportional modulated the signal. All this is going back over
thirty years ago when I played with the project.

Direction was resolved by the rotation coordinates of the dish.