METHOD AND DEVICE FOR DETERMINING VELOCITY MODULUS OF BALLISTIC TARGET USING ESTIMATES OF ITS RADIAL ACCELERATION WITH AMBIGUOUS MEASUREMENTS OF RADIAL VELOCITY Russian patent published in 2023 - IPC G01S13/58 

FIELD: radio positioning.

SUBSTANCE: in the claimed method, measured range ṙ_i and the elevation angle ε_i are used to calculate the current height of the BT z_i = ṙ_isinε_i. Weighted summation of a sample of values z_i is used to estimate height z_avg, which is used to calculate geocentric angle φ_avg = tan^-1(√{r_avg² - z_avg²}/(R_e+ z_avg) and acceleration g_{avg =} g₀ ([R_ecosφ_avg]/[R_e+z_avg])², where R_e is the radius of the Earth, g₀ is the acceleration of gravity on the surface of the Earth. The maximum measurable radial velocity ṙ_max = cF_p/4f₀ is calculated, where f₀ is the carrier frequency, F_p is the radar repetition rate and c is the speed of light. Weighted summation of a sample of range measurements is used to estimate its second increment Δ2ṙ and an unambiguous radial velocity ṙ_avg. Radial velocity differences |δṙ_i,i-1| = |ṙ_measi - ṙ_measi-1| are calculated. The sign of estimation Δ₂ṙ and the results of the comparison of |δṙ_i,i-1| with ṙ_max are used to determine the coefficients m_i (0, 1, 2, …) and calculate the current values of radial velocity ṙ_inci = ṙ_measi - m_iṙ_max that are unambiguous over the observation interval. Weighted summation of a sample of values ṙ_inci is used to estimate radial acceleration ṙ_avg and calculate the BT velocity modulus in the middle of the observation interval on the nonperturbed passive section of the ballistic trajectory.

EFFECT: increase of the accuracy of determining the speed of a ballistic target (BT) by eliminating the ambiguity of measuring its radial velocity ṙ_measi.

6 cl, 7 dwg, 5 tbl, 6 ex