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21.
中国近岸海域高度计JASON-1测量数据的波形重构算法研究 总被引：3，自引：1，他引：2
卫星雷达高度计的测量数据目前已被广泛应用于各个领域,但高度计在近海的测量数据却一直不可用,一方面是因为高度计在近岸海域的回波波形测量受陆地回波的影响,另一方面是因为一些校正量对近海不准确,如大气湿对流层校正、海洋潮汐校正以及大气高频因数校正等。通过对高度计在近海测量的回波波形进行重构处理,可以缩短近海数据不可用的距离,提高数据的数量和质量。以我国海域及邻近海域(14°~45°N,105°~130°E)为研究区域,采用四种波形重构算法(海洋算法、重力中心偏离算法、冰层算法二和阈值算法)对JASON-1高度计1 a共31个周期的测量波形重新进行了计算,比较了轨道交叉点处升轨和降轨的海面高度异常值以及海面高度值与验潮站的实测水位,结果表明重力中心偏离法比其他三种算法更适合我国近海的测高波形重构:计算结果精度最高,有效数目最多。 相似文献
22.
雷达高度计是测量海洋动力参数的重要传感器,为解决雷达高度计在近海测量数据不可用的问题,基于大量波形的分析及已有波形重构算法的比较,本文提出了一种基于波形分类和子波形提取的近海波形重构算法（OceanCS）.采用了验潮站的实测水位以及浮标的实测有效波高数据对算法的结果进行了验证.结果表明,本文提出的算法在近海的回波波形处理方面要优于其他五种算法（海洋算法、OCOG算法、Ice-2算法、Beta5算法和阈值算法）,并且不仅可反演海面高度、还可反演有效波高.通过对高度计的近海回波波形进行重构处理,可以提高近海测高数据的数量和质量. 相似文献
23.
本文研究最冷目标地物替代法计算Jason-2微波辐射计JMR年度漂移。针对Jason-2卫星微波辐射计(JMR),利用微波辐射计传输模型,建立JMR 3个通道的全球最低亮温观测值的理论计算模型,模拟其3通道全球地物观测最冷亮温;基于2008年—2012年Jason-2地球物理数据(GDR)产品中全球对地观测亮温序列和模型计算的最冷亮温,建立亮温序列的最小观测亮温统计模型,查找全球地物观测最冷亮温序列;根据地物年度变化特性,建立光谱分析模型,去除最冷亮温序列的年度谐波;去除年度谐波后,采用线性拟合的方法外推最冷亮温序列的理论最小值,并据此计算Jason-2微波辐射计仪器的年度漂移量。 相似文献
24.
One of the most important parameters for oceanic internal waves (IWs) is their amplitude. We have developed a method to retrieve the IW amplitude from nautical X-Band radar images based on the KdV equation for continuous stratified finite depth system. We have also tested the method of measuring the amplitude of IWs from X-Band radar backscatter image sequences acquired on June 2009 in the northeastern South China Sea. The method was applied in several radar images. Experiments show that the retrieval amplitudes are consistent with the in-situ observational amplitudes of IWs by using the towed thermistor chain and conductivity-temperature-depth (CTD) profile. The uncertainty of the method is also discussed. 相似文献
25.
利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测 总被引：4，自引：0，他引：4
<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is 相似文献
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黄海、东海上空春季气溶胶光学特性观测分析 总被引：11，自引：5，他引：11
2003年春季国家卫星海洋应用中心等几家单位在黄海和东海海区进行了为期40 d的二类水体信息测量试验,试验中使用手持太阳辐射计对海区上空大气光学特性进行了观测,并获得了大量晴空天气条件下的大气光学数据.利用本次试验获取的测量数据得到了黄海、东海海区春季的大气气溶胶光学特性,其中包括气溶胶光学厚度和气溶胶粒子谱分布.采用Langley方法对测量得到的太阳直射辐射量进行处理得到了海区上空气溶胶光学厚度,利用得到的气溶胶光学厚度来反演气溶胶粒子谱分布.反演结果表明无云情况下黄海、东海上空的气溶胶光学厚度在0.2~0.4左右,且气溶胶粒子谱分布的变化趋势也很接近;海区上空霾层较厚时测量得到的气溶胶光学厚度明显增大,最大接近0.8;气溶胶粒子谱分布的变化趋势发生了明显的变化. 相似文献
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随着航天技术的发展和新型微波载荷的发射(如3维成像高度计),越来越多的小入射角海洋观测雷达将投入运行,如何有效地利用这些小入射角的后向散射数据成为研究的热点课题。利用TRMM(Tropical Rainfall Measuring Mission)的PR(Precipitation Radar)后向散射系数NRCS(Normalized Radar Cross Section)数据对小入射角情况下的海面风速反演方法和风速反演精度进行研究,并对风速反演性能进行统计分析。基于无雨条件下的PR海面后向散射数据,建立小入射角情况下的风速反演算法和经验的GMF模型。风速反演结果分别与浮标、ASCAT进行交叉比对。结果表明:反演风速的偏差小于0.28 m/s,标准差小于1.51 m/s;在中等风速条件下,反演风速的偏差和标准差均小于低风速条件和高风速条件;0°—8°入射角范围内的风速反演精度明显优于8°—12°入射角范围的风速反演精度。 相似文献
28.
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
29.
On the basis of the satellite maps of sea level anomaly(MSLA) data and in situ tidal gauge sea level data,correlation analysis and empirical mode decomposition(EMD) are employed to investigate the applicability of MSLA data,sea level correlation,long-term sea level variability(SLV) trend,sea level rise(SLR) rate and its geographic distribution in the South China Sea(SCS).The findings show that for Dongfang Station,Haikou Station,Shanwei Station and Zhapo Station,the minimum correlation coefficient between the closest MSLA grid point and tidal station is 0.61.This suggests that the satellite altimeter MSLA data are effective to observe the coastal SLV in the SCS.On the monthly scale,coastal SLV in the western and northern part of SCS are highly associated with coastal currents.On the seasonal scale,SLV of the coastal area in the western part of the SCS is still strongly influenced by the coastal current system in summer and winter.The Pacific change can affect the SCS mainly in winter rather than summer and the affected area mostly concentrated in the northeastern and eastern parts of the SCS.Overall,the average SLR in the SCS is 90.8 mm with a rising rate of(5.0±0.4) mm/a during1993–2010.The SLR rate from the southern Luzon Strait through the Huangyan Seamount area to the Xisha Islands area is higher than that of other areas of the SCS. 相似文献
30.
