RANGE METER ON THE BASIS OF LINEAR-FREQUENCY MODULATION LFM

摘要

FIELD: measurement of range to target in the conditions of scanning at a use of a high pulse repetition rate.;SUBSTANCE: the on-board radar illuminates the preset space by pulse with a linear modulation of carrier frequency. At reception of the signal reflected from the target the range to the target is measured by the value of frequency drift- the linear-frequency modulation method, and by the time delay - the ambiguous range. The sequence of range measurements (LFM) and ambiguous range obtained at a single passage of the antenna beam on the target- the burst is averaged and the measured range is taken to be equal to such a value, which has with the average range of the LFM the same ambiguous coefficient for the repetition period at which the measurement was taken, and the ambiguous range coinciding with the average ambiguous range in a burst. The rate of closure with the target is also measured in the burst by the value of the Doppler shift of the non-modulated signal. The measured value of range is extrapolated with due account made for the measured value of speed. At subsequent measurements of range smoothing of the measured value of range occurs with due account made for the extrapolated value. At a quantity of measurements of the range to the target making it possible to consider the extrapolated range value to be exact, matching of the ambiguous coefficients of the measured and extrapolated ranges is carried out at the repetition period at which the range has been measured.;EFFECT: highly accurate range measurement.;5 dwg