A wavelet-transform gives the chance to reduce the influence of the Heisenberg's uncertainty principle on the obtained time-and-frequency representation of the signal. However, subject to Heisenberg's uncertainty principle, it is impossible to tell precisely what frequency signal is present at a given moment of time (it is possible to speak only about the range of frequencies) and it is impossible to tell at what precisely moment of time the frequency signal is present (it is possible to speak only about a time span).
It expands the possibilities of the method in comparison with the classical Fourier Transform. If it is necessary to define the time interval of a frequency presence the STFT is used that allows one to detect the presence of any frequency signal and the interval of its presence. The main drawback of the classical FFT is weak localization in the time domain. The most effective methods of height anomaly computation are based on the methods of discrete linear transformations, such as the Fast Fourier Transform (FFT), Short-Time Fourier Transform (STFT), Fast Wavelet Transform (FWT).
As of today, accurate determination of height anomaly is one of the most difficult problems of geodesy, even with sustainable perfection of mathematical methods, computer possibilities.