摘要 |
An improved method and system for removing time-varying Doppler shifts and the effects of turbulence from data comprising at least one processor operating to estimate the average instantaneous frequency; reduce or remove noise from the state space variables estimates describing the frequency of the target; compensate for the motion of the target to obtain motion compensated data and increase the coherency of the data, and reduce or remove the noise from the state space variables describing the frequency of the target using a filter or smoother. Alternately, the method and system may comprise at least one processor operating to estimate the average instantaneous frequency of the first harmonic of a moving target; the average instantaneous frequency being inputted into an error reduction subroutine; using state space estimates of the frequency, calculating a time warping to remove the effect of the Doppler shift; and focusing the data using a modified PGA. |