Patent ID: 9602189
Date: 2017-03-21
CPC Classifications: G01S,H04B

Claim:
1. A method for estimating a path-length difference between two paths followed by a target signal transmitted by a spacecraft or aircraft respectively to a first receiving antenna and a second receiving antenna of a receiving base, the method comprising the steps of: measuring a useful phase difference between signals corresponding to the target signal received respectively on the first receiving antenna and the second receiving antenna, each of the first receiving antenna and the second receiving antenna of the receiving base exhibits a main radiation lobe of a width equal to or greater than 20°; estimating the path-length difference as a function of useful phase difference measurements to perform an orbit or path recovery of said spacecraft or said aircraft; measuring the useful phase difference comprising either a correlation of the signals received respectively on the first receiving antenna and the second receiving antenna with a reference target signal, or the analysis of the signals received respectively on the first receiving antenna and the second receiving antenna using a Fast Fourier Transform (FFT) or Phase-Locked Loop (PLL); transmitting a calibration signal to the receiving base via a transmitting antenna; measuring a calibration phase difference between signals corresponding to the calibration signal received respectively on the first receiving antenna and the second receiving antenna; and compensating variations of the calibration phase difference measurements on the useful phase difference measurements.