METHOD OF MEASURING ELEVATION ANGLE OF AERIAL OBJECT IN METER RANGE OF ELECTROMAGNETIC WAVES Russian patent published in 2020 - IPC G01S13/68 

FIELD: radar ranging.

SUBSTANCE: invention relates to radar ranging and can be used in measuring elevation angle (EA) of an aerial object in meter range of electromagnetic waves. Method of measuring the elevation angle consists in receiving, using the vertical N-channel antenna array (AA), the aerial object (AO) radio signals, which are reflected from the underlying surface of the Earth. According to the invention, an array of quadrature signals X_n and Y_n of the received multi-channel signal AA is formed, then amplitude-normalized along N channels to receive relative amplitude of given antenna element AA. Simultaneously with amplitude normalization of signals, phase normalization is performed relative to signal phase of given element. Further, amplitude and phase-normalized multichannel signal is compared with calculated model signal values with given Fresnel reflection coefficients G_m, ϕ_m, preset AA in preset EA range, with preset EA pitch. Further, the amplitude-phase and normalized multichannel signals are compared by the condition of their discrepancy. Result of comparing these signals is presented as a sum of squares of "discrepancies": δx_m by x-quadratures, δy_m – by y-quadratures, δA_m – by A-amplitudes. Further, from the found values of the sum of the squares of the "discrepancies" δx_m, δy_m, δA_m, constructing a non-linear spectral function R_m by the rule: After that, on the array R_m the maximum value of the spectrum R_max, its position M_max on the angular coordinate is found and the decision is made on the measured G_AO elevation angle AO according to the rule: G_AO=d⋅M_max, where: d is the received size of discrete measurement step by EA, deg.

EFFECT: invention provides measurement of angular position G_AO of low-altitude AO in "their insensitivity zone θ" (G_AO<θ=1½–2 degrees); outside "insensitivity zone" C_AO≥2 degrees invention provides high accuracy of measuring elevation angle.

1 cl, 6 dwg