S.N. Kireev, V.A. Talanov

A SAR signal process algorithm development needs a trajectory signal record received during real flight. Because of high cost such tests the base development instrument is a simulation modelling. The received signal during the SAR modelling is presented as a sum of signals reflected from multitude of a scene point. However, the trajectory signal calculation for complicated scenes is time-taking. That's why authors usually refuse the law of intrapulse modulation and form one sample per each signal period. It limits model capabilities, doesn't let to take into account particularities of received path and features of transmitted signal. Authors propose algorithms [1] accelerating work full model hundreds times more. They based on calculation of two signal sample matrices. The first one takes into account agile processes during one signal repetition period. The second matrix takes into account slow pulse-to-pulse period processes. The total sample matrix is calculated by multiplying these two matrices. But scene point quantity can be up to many thousands during earth coverage. In this way these algorithms work not enough quickly because of large size of matrices. During the SAR earth coverage modeling at low elevation it is necessary to take into account a reciprocal shading of objects in region. Authors use a modification of «floating horizon» method for calculation of shading. For these objects are placed in a graticule of polar coordinate system. The calculation of «floating horizon» is accomplished for all points on the same isodel. During signal calculation the calculation intrapulse modulation for the same isodel points can be combined and the size of multiplying matrices can be reduced. In this paper restricts of proposed model are considered, inaccuracies are estimated. New algorithms provide additional accelerating of calculation three-five times as quick as compared with [1]. Additionally, the time of intrapulse sample calculation is not long as compared with total time of model work.