D. A. Mayorov, D. G. Mitrofanov, E. A. Gavrikova

The application of signals with pulse-to-pulse frequency tuning on aт accidental law is one of the advanced radar evolution. The usage of pulse-to-pulse frequency tuning allows to raise the interference resistance of radar system and to extend the information possibilities of radar. The complexity of the practical realization of perspective mode of frequency tuning in radar may be overcome by means of reducing the number of used carrier frequencies. But in this case, the single method of measuring an air object radial velocity with of pulse-to-pulse frequency tuning by an accidental law stops working effectively. In this connection the task of developing the measuring of an air object radial velocity for perspective radars with pulse-to-pulse frequency tuning under the limitation of number of used frequencies becomes actual. The idea of the decision the assigned task is in multiply usage of radar impulses of identical frequencies in one pack of signals. This will allow providing the necessary gain in signal-noise ratio on account of increasing the number of coherence accumulated pack impulses. The processing of locked-on signals includes their division on private channels, separation of quadrature components, the transformation in digital form with the help of analogous-digital transformers, the carrying out digital matched filtering of each impulse signal separately, the distribution of locked-on signals in order of linear increase of frequency and the formation of complex frequency characteristic of an air object. The processing of complex frequency characteristic is making by analogy with known method of measuring of air object radial ve-locity. It is necessary to lead the overrun of possible values of velocity and to make phase correction of complex frequency characteristic taking into account each of it to provide the measuring of radial velocity. The carrying out Fourier inversion of phase corrected complex frequency characteristics will allow getting a set of range profiles of an air object. In coincidence of actual and supposed value of radial velocity of an air object the coherent range profile of extremal informativity is forming. The entropy of such range profile data is minimal. The mathematical modeling confirmed the working capacity of the offered method of air object radial velocity estimation and the conservation the level of accuracy of measuring velocity valuation by reducing the number of used frequencies on the former level. The offered method is easily realized and has the following advantages: a possibility of judgmental estimate of air object radial velocity in mode of carrier frequency tuning at a small number of radar actual frequencies, the high interference resistance on account of pulse-to-pulse carrier frequency tuning on an accidental law, which lows the negative influence of impact frequency interferences, the simplicity of technical and digital realization. The offered method may be used in perspective radars of and conducting by pulse-to-pulse carrier frequency tuning in the inter-ests of radar measuring, and also to provide the selection of moving air objects against the passive interferences.