METHOD OF MEASURING INTERPERIOD FACTOR OF PASSIVE INTERFERENCE CORRELATION Russian patent published in 2011 - IPC G01S7/36 

FIELD: physics.

SUBSTANCE: received are interferences representing a mix of passive interferences (PI) and interfering signals in N periods of coherent set repetition, where N≥2 is integer. Generated are counts of complex envelope x_i,k, where i=i_m,i_n 1≤i_m,i_n≤N are numbers of two repetition periods of coherent set, k is the number of range element. Window of N_w range elements is generated. For each window range element, correlation of interferences is determined between i_m and i_n repetition periods of coherent set

, where is complex conjugate of , and interference power in i_m and i_n repetition periods of coherent set: , , in comparing obtained interference correlations z_k of interference power , in window range elements. Window range elements containing interfering signals are excluded. Remaining window range elements are used to derive PI correlation estimations between i_m and i_n coherent set repetition periods and estimation of the mix of PI and noise in i_m and i_n coherent set repetition periods: , , wherefrom magnitude of PI interperiod correlation factor is determined after estimating interference correlations z_k and interference power , . Interference correlation magnitudes Z_k in window range elements are used to define factors of phase irregularity Kφ(k) by the following formulas:

,

where φ_n is interference phase difference in i_m and i_n repetition periods, n-th range element, n=1,…,N_w≠k, by comparing interference power , in window range elements. The following condition is checked for observance:

, where u(·) is unit jump function, d is factor smaller than unity and selected to make probability of observance of said conditions with interfering noises is insignificant, N_c is constant that may not exceed the number of interfering signals in range window. N_c window range elements with minimum phase irregularity factors Kφ(k) and window range elements for which said condition are observed, are excluded.

EFFECT: higher accuracy of estimation.

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