Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Hydroacoustics

2 Ostrowski Z. J.

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Receiver of Doppler multistatic system for moving target detection and tracking

Ostrowski Z. J.

Hydroacoustics

2015

Vol. 18

141-152

The article presents a method for solving major structural problems that occur in the receiver used in the multistatic Doppler system, aimed at determination of the trajectory and velocity of a moving target. In the system two transmitters emit acoustic continuous sinusoidal waves at different frequencies. The signals, scattered from a moving target are received by four hydrophones. Beside of the echoes, much larger signals coming directly from transmitters are recorded. It has been proved that in the presence of the direct high-amplitude signal, using currently available A/D converters, there is no possibility to detect the Doppler shift of small signals. The proposed approach is based on the homodyne frequency conversion of the received signals. Subsequently, the constant component and other unwanted products of the frequency conversion are filtered. The results of computer simulation have shown the effectiveness of the adopted design solution.

The Doppler effect in a bistatic system for determining the position of moving targets

Ostrowski Z. J.

Hydroacoustics

2014

Vol. 17

161--170

The article presents the theoretical analysis and the results of numerical calculations of the Doppler effect it occurs in a system designed to determine the position and speed of a moving target. The transmitter is the source of the signal and it emits a sinusoidal, acoustic and continuous wave. Signal reflected off a moving target is received by four hydrophones. Based on the signals, four Doppler shifts are determined and inserted into a set of equations. The solution gives instantaneous target coordinates and the vector of target speed. Analytical formulas are given which describe the spectra of the Doppler shift of echo signals in a bistatic system, as well as numerically determined examples. Spectral lines are assigned to instantaneous target positions. This provides the basis for solving the above set of equations and the functioning of the system.