Altimetry method and system

A method altimetry to determine an elevation profile of a portion of the surface of the earth (S), comprising the steps of: (a) supplying a signal receiver (RX) on a first platform (S1) Flying above said portion of the surface of the earth for a time series of signals from the second wheel platform (S2) and scattered by said portion of the surface of the earth; (B) computing waveforms altimetry, indicative of the elevation profile of said portion of the surface of the Earth, when processing the received signals; wherein said step of computing waveforms altimetry comprising: (b.1.1) determining the correlation waveforms (XC) to cross-correlate the received signals with a plurality of frequency-shifted replicas of locally generated signals emitted, with the frequency offset of each replica Doppler shift corresponding to the average of the reflected signals in a given a particular region of the surface of the Earth time; (B.1.2) make a temporary change dependent Doppler frequency waveforms correlation in order to compensate for the extra delay induced by the spherical curvature of the wavefront of the signals emitted to the extent that it impinges on the surface of the Earth; (B2) incoherently summing the waveforms temporally displaced coordination (CXC) corresponding to the signal scattered by the same region of the surface of the Earth at different times during the movement of said first platform.