V.K. Volosyuk, V.F. Kravchenko, V.V. Pavlikov

Work investigates influence of weight processing of signals and amplitude-phase distribution (APhD) fields in the aerial aperture on efficiency of the radar-image's (RI) restoration by means of the modified algorithm of space-time signals - processing in radar stations with synthetic aperture (RSA). The kind of the modified ambiguity function (AmF) depends on a signal-to-noise ratio. Resolution of modified RSA can be more than in classical RSA. When a signal-to-noise ratio is increasing the width of main peak of AmF is narrowing, but level side-lobe level (SLL) of AmF simultaneously grows. High SLL leads to occurrence of additional maxima or borders in a vicinity of contrast sites of RI. It reduces efficiency of recognition of sounded objects at an interpretation stage. Decrease of SLL is reached with weight processing of waveform envelope ( ) and APhD of fields in the aerial aperture ( ). It is defined, that at modeling of optimum processing algorithms of the space-time signal, weight functions may be entering both in basic impulse, and into an unit impulse. Comparative analysis of RI which have been generated with use of algorithms of the classical and modified synthesis is carried out. It is shown, that at aspiration of a signal-to-noise ratio to infinity, kind of AmF of RSA aspires to delta-function. Thus the sizes of pixels are decreasing - formation of RI is characterised with the most resolution, and the speckle-noise dispersion on RI is increasing. Speckle-noise can be smoothed by means of various averaging filters at a stage of secondary processing. Influence of weight windows on quality of formation of RI with use, both classical windows, and new Kravchenko weight functions is analyzed. On the basis of comparison of values average modulus deviations of test RI from the ideal image, and also the visual analysis of simulated RI, the expediency of use of weight functions of Kravchenko in the modified algorithms of processing of space-time signals in RSA is proved.