| 摘要 |
FIELD: radio engineering, communication.SUBSTANCE: method includes simultaneous measurement of radial velocities of targets with the same systematic accuracy in the entire range when emitting one modulated pulse and when receiving reflected pulses, the duration of which may be shorter than the duration of the probing pulse. The source probing pulse is generated in the form of digital samples of a combined series of a large number of short elementary chirp pulses having the same duration and frequency deviation, but different pseudorandom values of the initial frequency. Reflected pulses received by an antenna are amplified, filtered with a filter, time-sampled and level-quantised with an analogue-to-digital converter. The generated samples are transferred to a null frequency via digital quadrature heterodyne mixing with a complex sinusoid with a defined frequency. The heterodyne mixing result is filtered with a digital quadrature low-pass filter (DQLF). Samples at the output of the DQLF are generated with a defined frequency and then processed with compression filters, pulse characteristics of which are tuned to given Doppler frequency values. The maximum signal amplitude delay at the outputs of the filters corresponds to the distance to the detected target without Doppler error, and the signal frequency measured using a discriminator technique at maximum amplitude values in two or three adjacent filters with the same systematic error in the entire range, corresponds to the Doppler frequency shift of the target, which is uniquely associated with its radial velocity.EFFECT: providing constant resolution of measuring distance to targets.16 dwg |
