METHOD AND DEVICE FOR DETERMINING VERTICAL SPEED OF BALLISTIC TARGET USING ESTIMATES OF THE FIRST AND THE SECOND INCREMENTS OF ITS RADIAL VELOCITY Russian patent published in 2023 - IPC G01S13/58 

FIELD: radio positioning.

SUBSTANCE: in the claimed method, measured range ṙ_i and elevation angle ε_t are used to calculate acceleration of gravity q_cp, geocentric angles ϕ₁, ϕ_avg and ϕ_N between the radar and the BT at the beginning, in the middle and at the end of the observation interval, as well as the maximum unambiguously measurable radial velocity ṙ_max = cF_p/4f₀ where f₀ is the carrier frequency, F_p is the radar repetition frequency, c - 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. Intersurvey differences of radial velocity |δṙ_i,i-1| = |ṙ_measi - ṙ_measi-1| are calculated. The sign of estimation Δ₂ṙ and the results of the comparing |δṙ_i,i-1| with ṙ_max are used to determine the intersurvey coefficients of ambiguity G_P and calculate the values of the 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 their first Δ₁ṙ and second Δ₂ṙ increments. Then, the vertical speed of the BT is calculated in the middle of the observation interval on the nonperturbed ballistic trajectory.

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

6 cl, 6 dwg, 3 tbl, 3 ex