FIELD: radio engineering, communication.
SUBSTANCE: method is carried out by irradiating an object on the side of a radar station (RS1) with a continuous chirp signal which is received at RS2 of the object to be recognised, directed through two channels and in one of said channels, the chirp signal is delayed by a time t3 and in the other the chirp signal is transmitted through an encoder which generates radio pulses that are different on duration of the chirp signal, after which the chirp signals are summed, power amplified and re-emitted towards RS1, where they are multiplied with the emitted chirp signal for further selection, at RS1, of two signals with frequencies: Fpi=2DiFmdfm/C±2Vif/C and Fpj=2DiFmdfm/C±2Vif/C+B, where C and Vi denote the speed of light and approach or divergence speed of RS1 and RS2; f, Fm and dfm denote frequency, modulation frequency and frequency deviation of the chirp signal; B is part of the frequency of a difference signal arising due to delay of the chirp signal; Di is the distance between antennae of the radar stations and selection of the known difference Δ=Fpi-Fpj=B, detection of which indicates the object is a "friend". An apparatus for recognition of an object based on the friend/foe principle comprises a frequency-based radio range-finder and a frequency-modulated signal re-radiator with chirp signal transmitters and receivers, which include transceiving antennae, mixers, differential frequency filters, encoders and decoders, a delay element, an adder and a power amplifier.
EFFECT: wider range of apparatus used to recognise objects.
2 cl
