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1. (WO2002008786) METHOD FOR DETERMINING HYDROGRAPHIC PARAMETERS, WHICH DESCRIBE A SEA SWELL FIELD IN SITU, USING A RADAR DEVICE

Pub. No.:    WO/2002/008786    International Application No.:    PCT/DE2000/002414
Publication Date: Jan 31, 2002 International Filing Date: Jul 21, 2000
IPC: G01S 7/41
G01S 13/89
Applicants: GKSS-FORSCHUNGSZENTRUM GEESTHACHT GMBH
SEEMANN, Jörg
SENET, Christian, M.
ZIEMER, Friedwart
Inventors: SEEMANN, Jörg
SENET, Christian, M.
ZIEMER, Friedwart
Title: METHOD FOR DETERMINING HYDROGRAPHIC PARAMETERS, WHICH DESCRIBE A SEA SWELL FIELD IN SITU, USING A RADAR DEVICE
Abstract:
The invention relates to a method for determining hydrographic parameters, which describe a sea-swell field in situ, in particular of the swell of the sea, the current and the depth of water, using a radar device. According to said method, a sequence of digitised signals is supplied in the form of spatial co-ordinates from the analogue signal sequences provided by the radar device. A three-dimensional, complex value wave frequency spectrum is determined by means of a Fourier transform from the sequence of digitised signals in the form of spatial co-ordinates. This wave frequency spectrum is subsequently filtered according to the dispersion relationship principle, said relationship interlinking the numbers of waves and the frequency of the sea swell, to localise the parameters specific to the swell, by separating the signals from the noise contained in the signal sequence supplied by the radar device. The height of the waves is then determined from the received signal-to-noise ratio. Finally, the parameters describing the current of the sea-swell field close to the surface and the depth of the water are determined for the three-dimensional spectral range, by localising the signal co-ordinates in the surface area defined by the dispersion relationship. The phase information concerning the waves detected in the sea-swell field, which is contained in the wave frequency spectrum, is then used to determine the parameters for a sea swell field.