A system and method for obtaining weather related information for a
portion of the Earth's atmosphere between a predetermined surface portion
of the Earth and an airborne object located over the predetermined
surface portion, and operating at a known altitude, using position
locating signals from a space vehicle. In one exemplary implementation
the space vehicle transmits a first position locating signal. The first
position locating signal is received by the airborne object directly from
the space vehicle. A second position locating signal from the space
vehicle is received by the airborne object after being reflected from the
predetermined surface portion at a known angle. Phase information from
the first and second position locating signals is used to determine a
refractivity of the atmosphere between the predetermined surface portion
and the airborne object. The refractivity is used to determine weather
related information for the atmosphere.