Eksperymentalna weryfikacja algorytmu RDA w systemie SAR pracuj�cym z fal� ci�g��

An analysis of Chosen Image Formation Algorithms for Synthetic Aperture Radar with FMCW

“…THE RDA In many applications SAR images are synthesized using the RDA which makes azimuth compression through the fast convolution of the raw signal and the reference function [13]. It means that the range-compressed radar's signal must be subjected to the Fourier transform in the azimuth direction, i.e., transferred into the range-Doppler -domain and then multiplied with the reference signal spectrum [1].…”

“…Their shape on the R-D plane is a hyperbole that reflects the function of radar-object distance changes (so called the range migration curve). The beat frequency of the down-converted signal in the FMCW system that is proportional to the distance may be expressed as a function of azimuth position as follows [13]     …”

“…The function (13) has been derived for a pulse radar, where the Doppler shift of the echo signal does not influence significantly on the target position along the image's range axis. In FMCW radars, the distance to the target is determined on the basis of the beat frequency, and the Doppler shift can disturb this value.…”

“…In FMCW radars, the distance to the target is determined on the basis of the beat frequency, and the Doppler shift can disturb this value. In this case the range migration function takes the following form [13]   Fig. 2.…”

“…2. The azimuth spectrum of the simulated signal [13] Thus, the image synthesis of the range-compressed signal by RDA can be divided into two basic steps: the range cell migration correction and the azimuth compression [14].…”