Abstract: To study the problem of fast and accurate Doppler frequency estimation in the noisy environment, this paper presents the algorithm for high-accuracy frequency estimation based on the continuous zoom in the local spectrum. First, the algorithm cursorily estimates the signal spectrum with FFT; then, the narrowband spectrum of interest is obtained; finally, the narrowband spectrum is analyzed by the method of frequency subdivision. Due to adopting twice window functions in time domain and frequency domain during the subdivision process, straining noise and analyzing the spectrum are organically combined. Not only are the estimate precision and frequency stability greatly improved but also the computational quantity is largely reduced.

Key words: continuous zoom in the local spectrum, spectrum estimation with high resolution, Doppler navigation adar, simulation