Method for measuring atmospheric refractivity

摘要

A method and system for determining a refractive index structure of a portion of atmosphere is described using first and second antennas mounted in spaced relation to one another at a terrestrial location and a radio signal from an airborne object. A difference in the phase between the radio signal as received at the first and second antennas is measured to determine an angle of arrival of the radio signals at the terrestrial location. A refractive index profile is determined, of the atmosphere, using the actual position of the airborne object and the angle of arrival. The radio signal may be an Automatic Dependent Surveillance Broadcast (ADS-B) signal sent from an aircraft. Humidity, pressure and temperature of the atmosphere may be determined from the refractive index information. The invention may be used for weatherpredictions.