Patent RU-2516221-C2 (RU)
Inventor: SAVINOV VIKTOR ANATOL EVICH
IPC: G01S13/00
Filed: 2012-01-13
Granted: 2014-05-20
Abstract: FIELD: physics, navigation. 
     SUBSTANCE: invention relates to measurement of radar characteristics of objects and can be used to measure both monostatic and bistatic scattering cross-section of irregularly shaped test objects with as applied to multiposition radar systems. The result is achieved due to that, in the existing method of measuring the scattering cross-section of test objects, which involves irradiating the test object with a pulsed signal of fixed wavelength, fixed power and fixed linear basis polarisation, emitted by an antenna of a measurement radar station in the direction of the test object, re-emission of the signal scattered by the test object from a direction corresponding to a given divergence angle of the radio-measuring radar system in the horizontal plane, using a system of M passive repeaters in the direction of the receiving antenna of a distributed receiving device, receiving said signal separately from each passive repeater, recording with subsequent comparison of power values of the signals scattered by the test object and a calibration reflector with a known bistatic scattering cross-section, mounted at the location of the test object in place of it, the test object is further irradiated with pulsed signals of fixed power and fixed polarisation of N-1 measurement radar stations of fixed wavelength; the signal scattered by the test object for corresponding divergence angles is re-reflected by a system of passive repeaters with low (less than 30 dB) side-lobe levels of a bistatic scattering indicatrix, mounted on a special measurement path, which provides quasi-planar distribution of electromagnetic field on one line which coincides with a fixed direction of optical axes of a system of receiving antennae of distributed receiving devices, which overlap with the wavelength range λ N , wherein from the divergence angle γ m  corresponding to the point of installation of each passive repeater, time selection of signals from each passive repeater at distributed receiving devices is performed through path difference of beams on paths R 2m  and R 3m ; the power of each coinciding and orthogonally polarised component is received and measured, compared with the power of signals of corresponding polarisation, reflected from the calibration reflector with a known bistatic scattering cross-section on corresponding polarisation, and the power of the coinciding and orthogonally polarised component of signals scattered by the test object and the calibration reflected is recorded, and the test object or calibration reflector is alternately rotated in the horizontal plane at fixed values of the orientation angle in the vertical plane, and when processing measurement results, the current orientation of the test object or calibration reflector is considered for all analysed values of divergence angles and wavelengths, as well as the mutual position of each measurement radar station relative to the test object and each passive repeater. The result is also achieved due to that the multiposition radar measurement system, designed to realise the method of measuring the scattering cross-section, is made in a certain manner based on the existing local hardware components and does not require large material expenses. 
     EFFECT: broader functional capabilities by providing simultaneous measurement of both monostatic and bistatic scattering cross-section of a test object at multiple divergence angles on coinciding and orthogonal polarisations of a linear basis at multiple wavelengths while reducing the measurement error. 
     2 cl, 3 dwg