Near zero grazing angle forward-scatter sea clutter measurement spectrum analysis

Abstract

There is a lack of published experimental forward-scattering radar sea clutter data at very low (almost zero) grazing angle over the sea. This data is necessary to provide a fundamental understanding of the operating environment for the development of forward-scatter radar systems for maritime applications. Experimental data has therefore been recorded at frequencies of 7.5 GHz, 9.3 GHz, 24 GHz, and 37.5GHz using Forward Scatter Radar with static, medium gain antennas for low sea states 1-3. Results of clutter power spectral density measurements are presented and conclusions drawn from the results.

Radar parameters influence on the clutter in maritime forward scatter radar

“…It can be easily seen, the spectral shape is reasonably invariant to the antenna beamwidth and major part of clutter is within 1 Hz bamdwidth. This also confirms that the slope is approximately 20-35 dB per decade as it was discussed in [8][9][10]. Probability density function (PDF) and cumulative distribution function (CDF) for the same clutter data are plotted on Fig.…”

“…In the maritime conditions, this FS approach allows detection of low targets in the presence of significant sea clutter. This paper is continuation of previous published work [5][6][7][8][9][10] and it presents the results of clutter studies of an FSR. Essentially this type of radar does not have range/angular resolution [3,5], clutter is picked up from the large surface area illuminated by Tx/Rx antennas.…”

“…Spectral and statistical analysis of the sea clutter data have been made and will be presented in the paper. Sea clutter has been discussed previously in [8][9][10] where it was shown that the clutter statistics obey mainly Rayleigh distribution while the spectra been demonstrated to be limited from above by 1Hz and the slopes were of 20 -35 dB per decade. These results are in good agreement with numerical simulation of near-zero grazing angle FS performed in [13] where spectral and statistical properties of clutter were discussed.…”

Measured forward‐scatter sea clutter at near‐zero grazing angle: analysis of spectral and statistical properties

“…Spatially distributed dynamic sea waves may be generally considered as obstacles forming backscatter, bistatic and FS signal interference with the direct signal. Indeed, it has been confirmed experimentally that the average values and amplitude fluctuation characteristics of signals scattered over a sea surface path at centimetre and millimetre wavelengths can be satisfactorily described by the model of the interference of direct and scattered beams [10, 11, 17, 18, 27, 28] as illustrated in Fig. 1.…”

Phenomenology of signals in FSR for surface targets detection

“…Indeed, it was shown [9][10][11], that in spite of the absence of range resolution in FSR the most critical clutters from vegetation, dynamic sea surface and similar are mainly concentrated in a low Doppler frequency band up to 1 Hz which enables efficient clutter rejection in the frequency domain.…”