Inversion Of Ocean Current And Analysis Of Influencing Factors Of Sea States Parameters With X-band Radar

In recent years, with the development of ocean remote sensing technology, theX-band marine radar as an important means of ocean monitoring causes people’s attention.Compared with traditional monitoring methods, the X-radar marine has many advantagesin the measurement of ocean waves and currents, such as low cost, convenient,economical and practical, high spatial and temporal resolution and so on. So thetechnology has a broad application prospects, and has a great progress in the past fewyears. But the research that our country develops in this respect is relatively late, so it hasimportant theoretical and practical significance to study the technology that the inversionof sea state parameters with X-band radar.This article briefly reviews the history and recent status of the research on theinversion of sea state parameters with X-band radar and presents the principles andtechnology roadmap by X-band radar. On this basis, the key technologies of currentestimation, the design of the band pass filter, the influence of resolution on the inversionresults are deeply researched.The sea current is an important sea state parameter and the inversion algorithm isbased on the dispersion relationship equation. The inversion of the current is the key stepof the full inversion procedure. In this paper, the fundamental and the high-orderdispersion relationship and the effect of sea current on the dispersion relationship areresearched. On this basis, four kinds of sea surface current inversion algorithm areanalyzed and the effectiveness of the algorithms is tested through analog andeXperimental data. The comparative analysis of the advantages and disadvantages of eachalgorithm provide basis for the improvement of the algorithm.The image spectrum usually contains signal which do not belong to the wave fieldbecause the sea clutter images are disturbed by noise. Hence, this phenomenon is boundto have a great impact on the inversion results. In order to improve the accuracy of the inversion, a band-pass filter is applied to the image spectrum. Based on the analysis of thepresent algorithm, a new band-pass filter algorithm is proposed and proved to be feasibleby the eXperimental data in the dissertation.In addition to being influenced by the algorithms, the inversion accuracy of the seastate parameters is also influenced by the sampling data. The influence of the resolutionon the inversion accuracy is researched through the analysis of the experimental datawhich are collected in the case that the number or the temporary resolution of the radarimage sequence is different in this paper. The results show that in order to obtain accurateinversion results, the rotation speed of the radar antenna can not be too low to ensure theappropriate frequency space, the number of the radar images sequences which are used toretrieve the sea state parameters can not be too few to ensure the appropriate frequencyresolution. Thereby the retrieval efficiency is improved and the retrieval accuracy is kept.