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1. chinaXiv:201605.00289 [pdf]

AN UNFOCUSED SAR DESIGN TO IMPROVE AZIMUTH RESOLUTION OF DUALFREQUENCY FULL-POLARIZED SCATTEROMETER

Wang, Gang; Dong, Xiaolong; Bao, Qingliu; Zhu, Di; Xu, Xingou
Subjects: Geosciences >> Space Physics

In order to satisfy a high resolution for the measurement of snow water equivalent, we use the system of using the dual frequency(X-band 9.6GHz and Ku-band 17GHz) and full polarization. This paper discusses the various system options(scanning pencil-beam, high PRF, high SNR) and tradeoffs considered for improving the azimuth resolution of scatterometer are required.

submitted time 2016-05-03 Hits733Downloads439 Comment 0

2. chinaXiv:201605.00284 [pdf]

THE ALTIMETER PRECISION COMPARISON BETWEEN SAR MODE AND CONVENTIONAL MODE THROUGH AIRBORNE EXPERIMENT

Xu, Ke; Liu, Peng; Shi, Lingwei; Wang, Lei; Yu, Xiufen
Subjects: Geosciences >> Space Physics

Compared with conventional radar altimeter (CRA), synthetic aperture radar altimeter (SARAL) is a new generation radar altimeter and has better height precision and spatial resolution. As using synthetic aperture technique, SARAL data processing is very different from CRA. To verify the performance and the processing algorithm, an airborne experimental system of SARAL is developed. The experimental system was installed in Y-12 aircraft, and a lot of data was obtained in the October 2014. The echo signal with SAR mode and conventional mode are obtained at the same time, so the standard deviations of the two modes are compared. The results indicate that the height precision of SARAL is improved about 1 times. The significant wave height value extracted from the SARAL waveform is very close to that of the buoy deployed at the experiment area.

submitted time 2016-05-03 Hits388Downloads256 Comment 0

3. chinaXiv:201605.00278 [pdf]

THE LATEST ASSESSMENT FOR THE REPROCESSED GDR PRODUCT OF HY-2A ALTIMETER

Liu, Yalong; Xu, Ke; Zhang, Youguang; Wang, Lei; Xu, Xiyu; Chen, Hua
Subjects: Geosciences >> Space Physics

This paper is aimed to assess the accuracy of HY-2A altimetry system. To further improve the accuracy and performance of HY-2A observed SSHs, several new treatments including 4 parameters maximum likelihood estimation (MLE4) retracking for Ku and C band, non-parameter sea state bias (NPSSB) model, and reprocessed dual-frequency altimeter ionospheric correction are included. The evaluation from dual-crossover comparison of the fully reprocessed level-2 sensor geophysical dataset records (SGDRs) data suggests that the algorithm and model improvements mentioned above give rise to remarkable promotion to the accuracy of the forthcoming version GDRs. In this study we conclude that the standard deviation of 5.79 cm is achieved from crossover comparison between HY-2A and Jason-2 sea surface height (SSHs), suggesting a promising situation of HY-2A altimetry datasets.

submitted time 2016-05-03 Hits504Downloads270 Comment 0

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