METHOD OF MEASURING ALTITUDE AND RADAR ALTIMETER WITH CONTINUOUS CHIRP SIGNAL USING SAID METHOD Russian patent published in 2015 - IPC G01S13/08 

FIELD: physics, navigation.

SUBSTANCE: invention relates to radar and can be used in on-board radar altimeters. The method includes emitting a continuous chirp signal towards the Earth's surface; receiving reflected signals at N repetition periods; filtering the reflected signal in a filter matched with probing signal modulation to obtain in each repetition period the amplitude envelope of the reflected signal with a sampling step which corresponds to the resolution of the probing signal; determining an estimate of the aircraft altitude at each of the N realisations of the amplitude envelope of the reflected signal in the following sequence: generating a multidimensional hypothesis on altitude, noise dispersion level and a parameter which defines the relationship between the backscattering pattern and the angular position of the resolved surface element; calculating the power of the received signal at ranges which correspond to the determined hypothesis based on a priori known data on radar altimeter parameters; calculating the composite function of conformity of the amplitude envelope of the received signal corresponding to the determined hypothesis; through enumeration of hypotheses on the maximum of the composite function of conformity, finding the most probable hypothesis, estimating the aircraft altitude, repeating aircraft altitude measurement at N repetition periods, averaging the altitude estimate on N measurements and obtaining the corresponding final altitude estimate.

EFFECT: high accuracy owing to a low fluctuation error when measuring altitude.

4 cl, 4 dwg