Zastosowanie zmodyfikowanego przetwarzania przestrzenno-czasowego do wykrywania obiektów morskich

• Autorzy: Górski T. , Kawalec A. , Czarnecki W.

Warianty tytułu

EN

Application of STAP techniques for detection of targets on sea surface

• Konferencja: Urządzenia i systemy radioelektroniczne (UiSR) ; (2 ; 13-15.06.2007 ; Soczewka k. Płocka, Polska)
• Języki publikacji: PL

Abstrakty

PL

W pracy przedstawiono analizę technologii adaptacyjnego przetwarzania przestrzenno-czasowego (ang. Space-Time Adaptive Processing - STAP) w zastosowaniu do wykrywania obiektów morskich. Do zweryfikowania możliwości stosowania tej techniki w systemach HF wykorzystano sygnały z rzeczywistego radaru pracującego na częstotliwości 12 MHz. Bezpośrednie zastosowanie techniki STAP było niemożliwe z powodu konieczności zapewnienia dużej liczby próbek danych treningowych algorytmu STAP. Dlatego zastosowano adaptacyjne przetwarzanie czasowe (ang. Time Adaptive Processing - TAP), co pozwoliło zredukować konieczną liczbę próbek danych treningowych. W pracy przedstawiono wyniki potwierdzające wykrycie obiektu poruszającego się w odległości 30 km od systemu radarowego.

EN

HF radar systems have a potential of detecting targets falling beyond an optical horizon. For this reason, more attention is paid to this topic last years, especially in the context of sea and ocean ship traffic surveillance on territorial waters, contiguous zone and the EEZ. There are, however, some problems related to Bragg scattering, non-Gaussianity of the clutter and non-stationarity of the clutter. Space-Time Adaptive Processing (STAP) may be a solution to some of these problems. STAP is a technique for processing two- -dimensional signals. One dimension is related to, so-called, slow-time axis (pulse to pulse processing). This dimension gives information about Doppler shift of the returning echo. Second dimension is an array antenna channel. This can be transformed into the information about the direction of arrival. STAP is an optimal technique to filter out a clutter from this two-dimensional signal. To verify this, real signals from existing 12 MHz HF radar systems were used to perform numerical experiments. The system consists of 16 antennas and range resolution is 0.4 km. Antennas are line-aligned and are standing at the sea shore. The system is located at the west coast of Brittany in France. Its prime task is to monitor sea currents in the area. The system utilizes Frequency Modulated Contninuous Wave (FMCW) with repetition interval of 0.26 s. The data from the system are organized in files. Each file contains time coherent recording from 2048 pulses which gives recording time of around 9 minutes. Unfortunately, to apply STAP technique it is necessary to feed algorithm with training data taken form different range cells. As a result of low range resolution it was impossible to do so. Therefore, in the first approach, Time Adaptive Processing (TAP) was used. The first step is to perform classical beamforming and then to apply adaptive processing in the time domain only. It reduced necessary number of training samples. On the other hand, to increase an available number of training samples, training data from other time-windows were taken to feed algorithm. Using this technique, moving target was detected at a distance of 30 km. Target was moving away from the radar system at the speed of 3 m/s which was in accordance with a range migration observed in subsequent instants in time. After these experiments, the modified STAP algorithm was applied. Modification involved altering training data supply scheme. This allowed for detecting the same target. A problem of non-Gaussianity of the sea clutter is treated in the separate research based on the simulated data.

Słowa kluczowe

PL

przetwarzanie sygnałów; detekcja; radar HF

EN

signal processing; detection; HF radar

• Wydawca: Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
• Czasopismo: Biuletyn Wojskowej Akademii Technicznej
• Rocznik: 2007
• Tom: Vol. 56, nr sp.2
• Strony: 157--164
• Opis fizyczny: Bibliogr. 3 poz., wykr.

Twórcy

autor

Górski T.

autor

Kawalec A.

autor

Czarnecki W.

• Wojskowa Akademia Techniczna, Wydział Elektroniki, Instytut Radioelektroniki, 00-908 Warszawa, ul. S. Kaliskiego 2

Bibliografia

• [1] R. Klemm, Principles of Space-Time Adaptive Processing, IEE, 2002.
• [2] W. L. Melvin, A Stap overview, IEEE Aerospace and Electronic Systems Magazine, vol. 19, part 2 - Tutorials, January 2004, 19-53.
• [3] T. Górski, J.-M. Le Caillec, L. Lecornu, A. Kawalec, W. Czarnecki, J. Pietrasiński, B. Solaiman, Space-Time Adaptive Processing analysis for the moving target on the sea surface indication purpose, 16-th International Conference on Microwaves, Radar and Wireless Communications MIKON 2006, Kraków, Polska, May 22-24 2006, 199-202.