The Study On Retrieval Method Of Significant Wave Height Of HY-2 Satellite Altimeter

Satellite altimeter has progressed over 30 years, With the development of satellite altimetry technology, satellite altimeter such as TOPEX|POSEIDON, Jason-1 and ERS-1/2, ENVISAT etc. has become an important tool for the study of ocean dynamic environment .The Chinese ocean dynamic environment satellite, namely HY-2(Haiyang-2 satellite), will be launched in 2011. The altimeter is an important remote sensing instrument on HY-2 satellite. This thesis is supported by the construction of HY-2 ground application system, which main objective is focus on the significant wave height (SWH) retrieval method of HY-2 satellite Altimeter. The result of this study will be applied to HY-2 data processing system of satellite altimeter. In this thesis, firstly, introduce the data classification and preprocessing method of HY-2 satellite altimeter; Secondly, study on the retrieval method of SWH from the simulation data of HY-2 satellite altimeter, and then show the steps of retrieval processing and result. Thirdly, study on the retrieval method of antenna mispointing angle form SZ-4 altimeter data, and then show the SZ-4 antenna mispointing angle information.Main study results as follows:1. To analyze the data classification of satellite altimeter and the procedure of data processing, then discuss the main steps in the data processing of satellite altimeter. From above study, to determine the data classification method of HY-2 satellite altimeter. HY-2 satellite altimeter data are divided into level 0, level 1 and level2, then the data processing method of level 1B and level 2 are introduced.2. To study the retrieval method of SWH of HY-2 satellite altimeter. Because HY-2 satellite has not been launched, So, SZ-4 altimeter data are used as simulation data for retrieving SWH. In this thesis, the retrieval model of SWH is discussed in detail. The thesis uses 6 steps to retrieve SWH, which include waveforms'1s average, thermal noise elimination, normalization, half power point calculation, waveform integration and significant wave height calculation. This thesis use of least square with iterative weight window fitting method, this method different weight coefficients are used in different position of waveform. The above method plan for applying to the SWH retrieval method of HY-2 satellite altimeter.3. To study the retrieval method of antenna mispointing angle. Antenna mispointing angle show the attitude stability of altimeter. The trailing edge of the sea surface return waveforms is fitted to calculate the mispointing angle of altimeter antenna. Using Hayne model and SZ-4 space-borne altimeter waveforms data, the altimeter antenna mispointing angle are calculated. The results of the calculation shows that SZ-4 space-borne altimeter antenna mispointing angle of altimeter antenna is almost wholly less than 0.025o, antenna mispointing angle is stable during computing time series.