METHOD FOR DETERMINING THE DISTANCE TO THE SURFACE OF EARTH Russian patent published in 2019 - IPC G01S13/32 

FIELD: radar ranging.

SUBSTANCE: invention relates to radar engineering and can be used in designing radar systems intended for determining range from a moving object to ground surface, using the principle of reflection of radio waves. Said result is achieved by emitting probing signals in the direction of the earth's surface, using radio pulses having a carrier frequency, duration, repetition period and consisting of N monochromatic subpulses with non-periodic phase-code internal pulse manipulation as probing signals, which is realized by modulation of M-sequences of initial phases of subpulses, which take one of two values 0 or π, by tuning the carrier frequency of the radio pulses from the radio pulse to the radio pulse according to the random equiprobable law in each repetition period and changing from the radio pulse to the radio pulse the repetition period of the radio pulses, the duration of the radio pulses and the number of monochromatic subpulses, receiving signals reflected from the ground surface, by conducting the matched filtering of the reflected signals using the codes forming the modulating M-sequences as weight coefficients, and determining the range to the earth surface (main stage), as well as by introducing a preliminary stage of detecting reflected signals and rough determination of distance to the surface of the earth, wherein at the preliminary stage of detecting reflected signals and coarse determination of range, duration, repetition period of radio pulses and number of monochromatic subpulses are fixed, and in the beginning of operation at the main stage during the propagation of the signal from the moving object to the ground surface and back, the value of the distance to the ground surface is determined, which is determined at the preliminary stage of detection of reflected signals and rough determination of the distance to the ground surface.

EFFECT: high autonomy of operation when determining range to surface of earth.

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