Ocean Wave And Oil Spill Retrievement Based On Ship-borne Microwave Remote Sensing Technology

With the development of the global maritime industry and the frequently occurren-ce of oil spills,it is of vital importance for the safeguard of the marine traffic and the emergency supervision of maritime affairs to acquire the ocean dynamic environmental elements such as the significant wave height in the ship navigation process and the sea pollution information such as oil spill distribution.The ship-borne microwave remote sensing system,which has special significance in the monitoring of marine environmen-ttal information especially on the oceangoing routes,is a supplement to the other platfo-rms for space ductility and time continuity.So this paper selects X-band marine radar and GNSS-R as the new-developing remote sensing technologies to explore the waves and oil spill information retrieval on the ship-borne platform in allusion to their special advantages in remote sensing and the innovative demands for ship-borne marine detect-ion.In the research of extracting oil spill information,the significant wave height meas-urement experiment using GNSS-R receiver and X-band marine radar on ship-borne pl-atform is made for the first time in china.The sea wave information is extracted using signal-to-noise ratio method based on wave spectrum by analyzing the radar images of X-band marine radar,and retrieved by the related time algorithm of interference in com-plex field(ICF)based on GNSS-R signal.After the final contrastive analysis,the two technologies are found to have strong consistency under the condition of the permitted error,which verifies the feasibility of the method on ship-borne platform to measure the significant wave height.In the research of extracting oil spill information,by structuring the noise judging image and setting the new neighborhood window of filtering,this paper puts forward an improved adaptive median filter algorithm to eliminate the same-frequency interference noise of the marine radar images acquired from the "7.16" oil spill accident at new port in Dalian.A power attenuation correction method is proposed to solve the uneven distri-bution in resolution and echo intensity by acquiring the average power distribution of radar images simultaneously.By removing the sea background power with the differen-cing method,the oil spill area is finally retrieved,which is verified with the infrared data obtained on the same sea area at the same time.Oil spill retrieval theory of foreign scholars using GNSS-R is only based on satellite-borne platform.Research on oil spill retrieval using GNSS-R is still blank in China.As a breakthrough,this paper builds a ship-borne GNSS-R double-base sea scattering geometry model by exploring ship-borne specular reflection point and the mean surface slope model.Combined with the Jacobian determinant method,the GNSS-R delay-doppler map(DDM)generation algo-rithm is established to generate oil spill DDM using X-band marine radar.The coupling relationship between signal characteristics and oil spill information in DDM is finally found out by the comparison with clean sea surface image under the same conditions,and the performance of retrying oil spill with different wind speed is analyzed.