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基于浮标数据的卫星雷达高度计海浪波高数据评价与校正 总被引：1，自引：1，他引：0
卫星雷达高度计是海浪有效波高（significant wave height,SWH）观测的重要手段之一,本文利用时空匹配方法对T/P、Jason-1、Envisat、Jason-2、Cryosat-2和HY-2A共6颗卫星雷达高度计SWH数据与NDBC（National Data Buoy Center,NDBC）浮标SWH数据进行对比验证,并对雷达高度计SWH数据进行校正。全部卫星雷达高度计SWH数据时间跨度为1992年9月25日到2015年9月1日,对比验证NDBC浮标共53个,包括7个大洋浮标。精度评价发现除T/P外,各卫星雷达高度计SWH的RMSE都在0.4~0.5 m之间,经过校正后,RMSE都有显著下降,下降程度最大为13.82%;对于大洋浮标,评价结果RMSE在0.20~0.28 m之间,结果明显优于全部NDBC浮标的精度评价结果;HY-2A卫星雷达高度计SWH在经过校正后数据质量与国外其他5颗卫星雷达高度计SWH数据质量差异较小。 相似文献
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HY-2A卫星海面高度数据质量评估 总被引：1，自引：0，他引：1
对HY-2A卫星雷达高度计数据进行筛选获取有效的观测点,利用HY-2A卫星第18~23周期数据和同时在轨的Jason-2数据进行交叉点选取,对两颗卫星在交叉点海面高度异常值的差值进行统计与分析,提出了基于交叉点差值统计特征的筛除HY-2A轨道数据方法,评估了HY-2A卫星雷达高度数据质量。结果显示,HY-2A卫星18~23周期阈值筛选去除的点个数占总海洋观测点约12%,HY-2A海面高度异常与Jason-2海面高度异常的标准偏差在7.0 cm,数据精度满足设计精度要求。 相似文献
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HY-2A卫星雷达高度计海面高度测量分析与评估 总被引：1，自引：0，他引：1
HY-2A卫星是我国首颗自主海洋动力环境卫星，已连续运行6年多。卫星上搭载的主载荷雷达高度计能够实现全天候、全天时全球海面高度、有效波高和海面风速的观测，这些观测数据已经广泛用于海洋防灾减灾、资源开发和海上安全等领域。为了全面了解HY-2A卫星雷达高度计多年来的整体观测性能，本文选取了2012年10月26日至2017年8月27日间的全部观测数据IGDR产品进行综合评价。通过自交叉和与Jason-2互交叉两种手段对HY-2A卫星雷达高度计测高能力进行评估。计算HY-2A升降轨自交叉点的测高不符值，发现HY-2A卫星雷达高度计在近全球海域内、升降轨高度异常差小于30cm的限制条件下，平均绝对高度误差为5.81cm，高度异常标准差为7.76cm；限制观测区域为南北纬60°范围内、海面高度异常升降轨交叉点处的差小于10cm的情况下，平均绝对误差可达3.95cm，海面高度异常标准差达4.76cm。通过和Jason-2卫星的互交叉，发现在南北纬66°范围内，交叉点高度异常差小于30cm的情况下，HY-2A和Jason-2的海面高度异常平均绝对误差为5.86cm，标准差为7.52cm，如果在该海域内将海面高度异常差限制在10cm内，平均绝对误差和标准差分别达到4.19cm和4.98cm。HY-2A卫星雷达高度计已经达到国际同类卫星雷达高度计测高水平，可以满足海洋科学研究、海洋环流反演等的需求。 相似文献
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卫星高度计海面风速的校准与验证 总被引：2，自引：1，他引：1
为了改善不同卫星高度计海面风速数据之间的一致性,以浮标数据为基准,对国内的HY-2A和国外的T/P、GFO、Jason-1、Envisat、Jason-2、CryoSat-2共7颗卫星高度计的海面风速数据进行了分析,给出了各个卫星高度计的海面风速校准公式,并对其校准效果进行了验证。验证结果表明:各个卫星高度计的海面风速在经过校准后,与浮标海面风速差异的均值和均方根都有所降低,其中HY-2A最为显著。经过校准后所有卫星高度计的海面风速与浮标海面风速差异的均值都在±0.2m/s以内。除了HY-2A、GFO和Jason-1,其余4颗卫星高度计校准后的海面风速与浮标海面风速差异的均方根都在1.6m/s以下。由此可以得出结论,利用本文的校准公式对各个卫星高度计(特别是HY-2A卫星高度计)的海面风速进行校准,可以有效减少其与浮标海面风速之间的差异。 相似文献
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国内外对海上阵风的研究并不多,且大多集中在阵风预报和应用研究方面,对于海洋阵风数据的获取技术未见文献系统论述。本文利用HY-2B卫星雷达高度计观测的后向散射系数,结合校正微波辐射计观测的亮度温度信息,提出联合反演阵风风速的方法。两个遥感载荷联合反演得到的阵风风速与2019–2021年美国国家浮标数据中心（NDBC）浮标数据进行真实性检验,结果显示:阵风风速均方根误差（RMSE）为0.98 m/s,相关系数为0.82;基于本方法利用国外同类卫星Jason-3得到的阵风风速与2016–2018年NDBC浮标数据的RMSE为0.96 m/s,相关系数为0.88。本文在HY-2B卫星雷达高度计海面风速观测的基础上,纳入同一卫星平台校正微波辐射计的同步观测信息联合实现了海面阵风的观测,数据的比对结果证明文中方法具有较高的观测精度。同时,该方法对于具有相同观测体制的国内外卫星也适用。 相似文献
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HY-2A卫星雷达高度计数据的全球统计评价及质量分析 总被引：6，自引：4，他引：2
自HY-2A卫星发射以来,针对HY-2A卫星雷达高度计产品的交叉定标、真实性检验及质量评估工作一直在持续开展。本文主要以HY-2A卫星高度计第44周期的IGDR产品数据为例,通过使用全球分布图、二维直方图和每日均值统计的方法完成了与Jason-2IGDR产品的比对验证,同时对主要环境校正参数及地球物理产品的数据质量稳定性进行了分析,结果显示高度计产品数据质量较稳定,此外利用HY-2A卫星升降轨交叉点海面高度差、与Jason-2卫星交叉点海面高度差以及沿轨海平面异常数据分析的方法进行了HY-2A卫星高度计观测系统的性能评估,结果显示,HY-2A卫星海面高度精度约为7.48cm,精度接近Jason-2,能满足海洋应用与科学研究的需要。 相似文献
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有效波高反演对于海洋工程及海洋环境安全具有重要意义.我国海洋二号(HY-2A)卫星载有散射计和高度计等获取海洋要素的仪器.散射计可获取海洋风场数据但无法直接获取有效波高数据,高度计可获取海洋有效波高数据但覆盖区域狭小.本文将散射计与高度计各自优势结合,利用支持向量回归(SVR)和长短期记忆(LSTM)智能算法反演散射计... 相似文献
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HY-2卫星雷达高度计时标偏差估算 总被引：2，自引：0，他引：2
卫星雷达高度计是海洋遥感监测的重要传感器之一,测高系统和定轨系统是高度计重要的组成部分。若两系统使用不同的系统时钟,则获得的轨道高度和卫星测距值之间可能会存在一个时标偏差,该时标偏差会降低卫星雷达高度计的海面高度测量精度。针对HY-2卫星雷达高度计的时标偏差问题,本文分析了时标偏差对测高精度的影响,介绍了一种使用自交叉点数据估算时标偏差值的方法,并基于HY-2卫星雷达高度计第21个周期数据开展了时标偏差修正实验。时标偏差修正后HY-2自交叉点的海面高度差值(也称"不符值")分布收敛程度有了明显的提高,其RMS均方根值从24.7 cm减小到了7.0 cm,HY-2与Jason-2互交叉点的不符值的RMS也从16.6 cm减小到了7.3 cm。这表明本文介绍的时标偏差修正方法可有效地提高HY-2卫星雷达高度计的测高精度。 相似文献
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The validation of the significant wave height product of HY-2 altimeter-primary results 总被引：6，自引：5，他引：1
CHEN Chuntao ZHU Jianhu LIN Mingsen ZHAO Yili HUANG Xiaoqi WANG He ZHANG Youguang PENG Hailong 《海洋学报(英文版)》2013,32(11):82-86
The HY-2 satellite was successfully launched on 16 August 2011. The HY-2 significant wave height （SWH） is validated by the data from the South China Sea （SCS） field experiment, National Data Buoy Center （NDBC/ buoys and Jason-1/2 altimeters, and is corrected using a linear regression with in-situ measurements. Com- pared with NDBC SWH, the HY-2 SWH show a RMS of 0.36 m, which is similar to Jason- 1 and Jason-2 SWH with the RMS of 0.35 m and 0.37 m respectively; the RMS of corrected HY-2 SWH is 0.27 m, similar to 0.27 m and 0.23 m of corrected Jason-1 and Jason-2 SWH. Therefore the accuracy of HY-2 SWH products is close to that of Jason-1/2 SWH, and the linear regression function derived can improve the accuracy of HY-2 SWH products. 相似文献
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HY-2 has been launched by China on August 16, 2011 which assembles multi-microwave remote sensing payloads in a body and has the ability of monitoring ocean dynamic environments. The HY-2 satellite data need to be calibrated and validated before being put into use. Based on the in-situ buoys from the Nation- al Data Buoy Center （NDBC）, Ku-band significant wave heights （SWH, hs） of HY-2 altimeter are validated. Eleven months of HY-2 altimeter Level 2 products data are chose from October 1, 2011 to August 29, 2012. Using NDBC 60 buoys yield 902 collocations for HY-2 by adopting collocation criteria of 30 min for tempo- ral window and 50 km for a spatial window. An overall RMS difference of the SWH between HY-2 and buoy data is 0.297 m. A correlation coefficient between these is 0.964. An ordinary least squares （OLS） regression is performed with the buoy data as an independent variable and the altimeter data as a dependent vari- able. The regression equation of hs is hs （HY-2）=0.891 × hs （NDBC）＋0.022. In addition, 2016 collocations are matched with temporal window of 30 rain at the crossing points of HY-2 and Jason-2 orbits. RMS difference of Ku-band SWH between the two data sets is 0.452 m. 相似文献
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中国HY-2卫星雷达高度计有效波高真实性检验 总被引：9，自引：5，他引：4
Chinese Haiyang-2(HY-2) satellite is the first Chinese marine dynamic environment satellite. The dual-frequency(Ku and C band) radar altimeter onboard HY-2 has been working effective to provide operational significant wave height(SWH) for more than three years(October 1, 2011 to present).We validated along-track Ku-band SWH data of HY-2 satellite against National Data Buoy Center(NDBC) in-situ measurements over a time period of three years from October 1, 2011 to September 30, 2014, the root mean square error(RMSE) and mean bias of HY-2SWH is 0.38 m and(–0.13±0.35) m, respectively. We also did cross validation against Jason-2 altimeter SWH data,the RMSE and the mean bias is 0.36 m and(–0.22±0.28) m, respectively. In order to compare the statistical results between HY-2 and Jason-2 satellite SWH data, we validated the Jason-2 satellite radar altimeter along-track Ku-band SWH data against NDBC measurements using the same method. The results demonstrate the validation method in this study is scientific and the RMSE and mean bias of Jason-2 SWH data is 0.26 m and(0.00±0.26) m,respectively. We also validated both HY-2 and Jason-2 SWH data every month, the mean bias of Jason-2 SWH data almost equaled to zero all the time, while the mean bias of HY-2 SWH data was no less than –0.31 m before April2013 and dropped to zero after that time. These results indicate that the statistical results for HY-2 altimeter SWH are reliable and HY-2 altimeter along-track SWH data were steady and of high quality in the last three years. The results also indicate that HY-2 SWH data have greatly been improved and have the same accuracy with Jason-2SWH data after April, 2013. SWH data provided by HY-2 satellite radar altimeter are useful and acceptable for ocean operational applications. 相似文献
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Significant wave height(SWH) can be computed from the returning waveform of radar altimeter, this parameter is only raw estimates if it does not calibrate. But accurate calibration is important for all applications, especially for climate studies. HY-2a altimeter has been operational since April 2012 and its products are available to the scientific community. In this work, SWH data from HY-2A altimeters are calibrated against in situ buoy data from the National Data Buoy Center(NDBC), Distinguished from previous calibration studies which generally regarded buoy data as "truth", the work of calibration for HY-2A altimeter wave data against in situ buoys was applied a more sophisticated statistical technique—the total least squares(TLS) method which can take into account errors in both variables. We present calibration results for HY-2A radar altimeter measurement of wave height against NDBC buoys. In addition, cross-calibration for HY-2A and Jason-2 wave data are talked over and the result is given. 相似文献
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HY-2 A (Haiyang-2 A) satellite was launched on August 16, 2011 and radar altimeter is one of its main payloads. We reprocessed two years of HY-2 A altimeter sensor geophysical dataset records (SGDR) data. This paper presents the main results in terms of reprocessed HY-2 A altimeter data quality: verification of data availability and validity, monitoring several relevant altimeter parameters, and assessment of the HY-2 A altimeter system performances. A cross-calibration analysis of reprocessed HY-2 A altimeter data with Jason-2 was conducted. The reprocessed HY-2 A altimeter data show good quality and have a low level of noise with respect to Jason-2. The same geophysical correction methods were used to calculate the sea surface height (SSH) for the two missions. The mean standard deviations of the crossover differences for HY-2 A and Jason-2 are 5.24 cm and 5.34 cm, respectively. The mean standard deviation of the crossover differences between HY-2 A and Jason-2 is 5.37 cm. These show that HY-2 A can provide SSH measurements at almost the same level of accuracy as Jason-2. The relative SSH bias between HY-2 A and Jason-2 due to the Ultra Stable Oscillator (USO) drift is obviously observed, and it can affect the calculation of mean sea level and should be further studied and corrected. 相似文献
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SARAL/AltiKa GDR-T are analyzed to assess the quality of the significant wave height (SWH) measurements. SARAL along-track SWH plots reveal cases of erroneous data, more or less isolated, not detected by the quality flags. The anomalies are often correlated with strong attenuation of the Ka-band backscatter coefficient, sensitive to clouds and rain. A quality test based on the 1 Hz standard deviation is proposed to detect such anomalies. From buoy comparison, it is shown that SARAL SWH is more accurate than Jason-2, particularly at low SWH, and globally does not require any correction. Results are better with open ocean than with coastal buoys. The scatter and the number of outliers are much larger for coastal buoys. SARAL is then compared with Jason-2 and Cryosat-2. The altimeter data are extracted from the global altimeter SWH Ifremer data base, including specific corrections to calibrate the various altimeters. The comparison confirms the high quality of SARAL SWH. The 1 Hz standard deviation is much less than for Jason-2 and Cryosat-2, particularly at low SWH. Furthermore, results show that the corrections applied to Jason-2 and to Cryosat-2, in the data base, are efficient, improving the global agreement between the three altimeters. 相似文献
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卫星海面高度数据对于监测全球海面高度具有重要的意义,所以卫星高度数据的定标和检验变得至关重要。海洋二号C（HY-2C）卫星是继海洋二号B卫星后的第二颗业务卫星,于2020年成功发射升空。然而,目前对HY-2C卫星高度计的数据质量了解甚少,所以对HY-2C卫星的海面高度数据进行质量分析具有重要的意义。本文以同期观测的HY-2B卫星和Jason-3卫星的地球物理数据（GDR）为参考,对HY-2C卫星遥感地球物理数据（SGDR）中的海面高度数据进行质量分析。结果显示,在星星交叉定标中使用3种常见的交叉定标插值方法对HY-2C卫星的海面高度异常数据进行自交叉点分析时,HY-2C卫星海面高度异常数据质量分析的结果不同。其中使用三次样条插值方法进行质量分析的结果最优,得到海平面高度异常差的平均值为0.03 cm,标准差为6.17 cm。此外,对HY-2C卫星和HY-2B卫星互交叉点海面高度异常差异的平均值为?0.47 cm,标准差为5.32 cm;HY-2C卫星SGDR与Jason-3卫星GDR的海面高度异常数据进行互交叉点分析,得到海平面高度异常差的平均值为?0.3 cm,标准差为5.32 cm,这些数据表明HY-2C卫星的测高精度与HY-2B卫星、Jason-3卫星一致。因此HY-2C高度计产品数据质量稳定,能满足海洋应用和科学研究的需要。 相似文献