RU-2024132950-A - Method for determining the range to radiation sources using passive sonar

Inventors

• Гампер Лев Евгеньевич
• Сопина Ольга Павловна

Assignees

• Акционерное Общество "Концерн "Океанприбор"

Dates

Publication Date

20260504

Application Date

20241101

Claims (1)

1. A method for determining the range to radiation sources using a passive sonar comprising: receiving a signal plus interference by a wide-aperture receiving system (RS) of M spaced antennas (M≥3) in the Fresnel zone, preliminary processing including: converting acoustic signals into electrical signals, amplifying, filtering, synchronous sampling, analog-to-digital conversion and frequency domain conversion (FFT - fast Fourier transform), orienting the antenna directivity characteristics in the direction α S to the assumed location of the radiation source S, indicating within a given sector the directions α and the range interval D of the observation field with a coordinate grid (CG), the nodes of which with numbers p (p=1,…, P) and q (q-1,…, Q) correspond to the assumed locations of S pq with coordinates and scales of directions α (degrees) and ranges D (meters) in the observation sector and range interval <D min , D max >, with interval δ D , as well as with pq-th data cells calculated in advance - when assigning the parameters of the KS and scales, in each node of the KS a virtual point R pq is assigned, the coordinates of which <α p , r q > coincide in direction with α p , but differ in range: where γ f is the scale factor: characterized in that: in the data cells of each pq-ro node of the CS, a table for converting the input sample from the antenna adders, of dimension M×M, is organized, for which two sets of signal propagation times to the antenna centers are calculated - from the expected point S pq , and - from the virtual point R рд , according to the trigonometry formulas, using the coordinates of the centers of the antennas PS and the speed of sound in the medium c, two complex phase vectors are organized at each frequency ƒ k : for the point and for the point where ƒ k is the discrete frequency in the reception range corresponding to the k-th element of the Fourier transform, m-1,…, M, these vectors are multiplied and subjected to the standard “matrix inversion” transformation: at the next FFT cycle, signal arrays from the outputs of the antenna combiners in each pq-th cell of the CS at each frequency ƒ k are multiplied by the conversion table receiving modified signal samples then compensate for the signal propagation times by multiplying the modified signal samples at each frequency ƒ k by the phase factor after which, at each frequency ƒ k, they sum up by m=1,…, M and calculate the squares of the modulus of the sums, then sum up the squares of the modulus by frequency ƒ k in the reception range, average over a given number of FFT cycles in the corresponding pq-x data cells and the resulting P×Q table is displayed on the indicator, and the distances to the radiation sources are determined by the positions of the maxima of their CO on the linear scale D of the indicator.