| Synthetic Aperture Radar is an active microwave sensor which canobserve the earth by all time and condition. SAR has the advantages ofthe full earth coverage and high spatial resolution. So it can be usedin ocean observation, environment and disaster monitoring. SAR has beenan major measurement of earth. By now, many kinds of SAR sensors appearwith different bands, polarizations and work mode. They have the differentaccuracy to the object. To develop the technique of sea applications ofSAR, it is important to evaluate the effect of radar parameter and thework mode on the accuracy of retrieved parameters of the observed object.In this study, we develop a model for SAR image simulation andretrieval. This model can be used for the investigation radar parameterand work mode selection. Combined with SAR wave retrieval model, thesuggestion of selection for SAR work mode, incident angle, resolution,swath, radiometric accuracy is listed below:Incident angle of20o and30o is preferable for SAR wave retrieval,40o and50o is middle and the low and high incident angle will bring themuch error. The higher spatial resolution can not give the higher accuracy.It will not be the best result from the SAR image with the spatialresolution of higher as3m. On the contrary, the resolution of25m canbring a good result. It is recommended that dual or pol-polarization ispreferable for wave retrieval with high accuracy. SAR images with VVpolarization are better than that with HH polarization. The effect ofradiometric accuracy is mostly on the retrieval of significant wave height.From the analysis of SAR simulation data, the radiometric accuracy shouldbe confined to2dB if we ensure the retrieved error within20%. |
