共查询到19条相似文献，搜索用时 125 毫秒
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本文利用2016年的AMSR2、GMI、WindSat和HY-2A RM等星载微波辐射计海表温度（SST）数据，分析了北极卫星遥感SST数据的时空覆盖和产品精度情况。结果表明:北极星载微波辐射计SST冬季覆盖率和有效覆盖天数要低于夏季，GMI的SST有效覆盖率较低，AMSR2较高，联合使用AMSR2、GMI、WindSat和HY-2A RM星载微波辐射计SST数据，2月份覆盖率在12%~15%之间，有效观测天数优于26 d，8月份覆盖率全月高于26%，有效观测天数优于29 d。北极地区星载微波辐射计SST数据的误差均要大于全球平均水平，AMSR2数据精度较好，WindSat与AMSR2的精度相当，GMI的均方根误差约是AMSR2的2倍，HY-2A RM数据精度低于其他星载微波辐射计水平。 相似文献
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HY-2微波辐射计降雨条件下海面风速反演算法研究 总被引：1，自引：0，他引：1
由于降雨改变了海洋-大气的辐射/散射特性，长期以来星载遥感器在降雨条件下进行海面风速信息提取存在困难。本文针对自主海洋动力环境卫星海洋2号（HY-2）搭载的扫描微波辐射计，分析了不同频段亮温对降雨和海面风速敏感性，自此基础上获得了一种对降雨不敏感的亮温通道组合，该亮温通道组合对海面风速的敏感性甚至高于原有亮温通道。本文利用该亮温通道组合建立了降雨条件下的风速反演算法，并将反演结果与WindSat全天候风速产品、HY-2微波辐射计原有风速产品以及浮标实测数据进行了比较。结果表明本文算法在降雨条件下的反演误差小于2m/s，明显优于原有HY-2微波辐射计风速产品，验证了本文发展的算法在降雨条件下的风速反演能力。 相似文献
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星载微波辐射计空间分辨率增强算法研究 总被引：1，自引：0，他引：1
由于天线尺寸和重量受到限制,星载微波辐射计的空间分辨率通常都比较低.同时在测量地理参数时往往要用到辐射计的多个频率通道测量值,这就需要把不同通道的空间分辨率统一成某个较高空间分辨率.因此,出于应用的目的,利用微波辐射计空间分辨率增强算法来得到较高分辨率的图像很有必要.简单介绍了增强星载微波辐射计图像空间分辨率的几种算法,详细叙述了Backus-Gilbert反演算法的原理.设计了带有一些地物特征的人工合成图像,并使用BG反演算法对一模拟辐射计的生成图像进行了增强处理.从处理前后的图像对比可知,无论辐射计测量是否含有噪声,BG反演算法都很好地提高了辐射计生成图像的空间分辨率.在考虑噪声时,通过分析增强处理后图像与人工合成图像之间的相关性,仔细挑选协调参数,对分辨率和噪声进行了较好的折中处理. 相似文献
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微波辐射传输方程是海洋-大气微波遥感的理论基础,本文基于晴空条件下AMSR-E 10.7GHz水平与垂直极化亮温数据,将平静海面的亮温观测结果与4种海水相对电容率模型和2种大气水汽吸收模型的计算结果进行比较,确定了海水相对电容率模型与水汽吸收模型,基于上述模型和实测亮温数据反演了风致各项同性海面发射率,其与已有的经验模型结果基本一致,由此建立了星载微波辐射传输模型;利用建立的辐射传输模型计算亮温与AMSR-E观测亮温分别反演了海表面温度与海表面风速,验证了所建微波传输模型的有效性。本文的研究结果可为星载微波辐射计亮温定标、海洋地球物理参数提取奠定基础。 相似文献
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红外和微波辐射计反演海表面温度的比较 总被引：1，自引：0，他引：1
介绍了红外辐射计和微波辐射计测量海表面温度的原理,分析了它们各自在反演海表面温度时的差异。在全球范围的海表面温度的遥感监测中,红外辐射计和微波辐射计的遥感精度受到多种因素影响。传感器本身的噪音、算法反演精度、传感器分辨率、搭载卫星的全球覆盖率等自身因素使辐射计的探测资料产生差别;大气状况、海面风速、测量海洋不同深度海水的表征温度等外界因子也同时影响着红外辐射计和微波辐射计的遥感精度。了解红外波段和微波波段的辐射计在各方面的优劣,有助于发挥各自特长,有效提高卫星监测海表面温度的精度。 相似文献
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介绍了红外辐射计和微波辐射计测量海表面温度的原理，分析了它们各自在反演海表面温度时的差异。在全球范围的海表面温度的遥感蛉测中，红外辐射计和微波辐射计的遥感精度受到多种因素影响。传感器本身的噪音、算法反演精度、传感器分辨率、搭载卫星的全球覆盖率等自身因素使辐射计的探测资料产生差别：大气状况、海面风速、测量海洋不同深度海水的表征温度等外界因子也同时影响着红外辐射计和微波辐射计的遥感精度。了解红外波段和微波波段的辐射计在各方面的优劣，有助于发挥各自特长，有效提高卫星监测海表面温度的精度。 相似文献
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本文利用Ｓｅａｓａｔ－Ａ卫星辐射计实测的大气中的水气含量、云中液态水含量及降雨强度等参数计算大气对微波的衰减，从而实现对１４．５９ＧＨｚ微波散射计衰减进行补偿之目的。 相似文献
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一维综合孔径微波辐射计能够有效提高观测的空间分辨率，其观测入射角通常在0°~55°范围内变化。为了开发适用于一维综合孔径微波辐射计的海面温度反演算法，需要评估其观测亮温对海洋大气环境要素的敏感性。利用海面发射率模型和大气辐射传输模型，构建了适用于一维综合孔径微波辐射计的微波海洋大气辐射传输模式，研究了C波段垂直和水平极化微波辐射亮温在不同入射角下对海洋大气环境要素的敏感性变化情况，并定量计算了相应的敏感系数。结果表明:垂直和水平极化亮温对海洋大气环境要素的敏感性表现出不同的特性。随着入射角的增大，垂直极化亮温对海面温度的敏感性增强，对海面风场的敏感性相对减弱；水平极化亮温则相反。由大气水汽含量和云液态水含量误差引入的垂直和水平极化亮温误差随入射角增大而增大，但是，即使在55°的大入射角下垂直和水平极化亮温误差仍小于0.12 K。对于海面温度反演精度优于1 K的要求，一维综合孔径微波辐射计的测温精度需优于0.6 K。研究结果对于一维综合孔径微波辐射计海面温度反演算法的研究和载荷设计具有一定的理论指导意义。 相似文献
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Compared with traditional real aperture microwave radiometers, one-dimensional synthetic aperture microwave radiometers have higher spatial resolution. In this paper, we proposed to retrieve sea surface temperature using a one-dimensional synthetic aperture microwave radiometer that operates at frequencies of 6.9 GHz, 10.65 GHz,18.7 GHz and 23.8 GHz at multiple incidence angles. We used the ERA5 reanalysis data provided by the European Centre for Medium-Range Weather Forecasts and a radiation transmission forward model to calculate the model brightness temperature. The brightness temperature measured by the spaceborne one-dimensional synthetic aperture microwave radiometer was simulated by adding Gaussian noise to the model brightness temperature.Then, a backpropagation(BP) neural network algorithm, a random forest(RF) algorithm and two multiple linear regression algorithms(RE1 and RE2) were developed to retrieve sea surface temperature from the measured brightness temperature within the incidence angle range of 0°–65°. The results show that the retrieval errors of the four algorithms increase with the increasing Gaussian noise. The BP achieves the lowest retrieval errors at all incidence angles. The retrieval error of the RE1 and RE2 decrease first and then increase with the incidence angle and the retrieval error of the RF is contrary to that of RE1 and RE2. 相似文献
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Assessment of the initial sea surface temperature product of the scanning microwave radiometer aboard on HY-2 satellite 总被引：4，自引：3，他引：1
ZHAO Yili ZHU Jianhu LIN Mingsen CHEN Chuntao HUANG Xiaoqi WANG He ZHANG Youguang PENG Hailong 《海洋学报(英文版)》2014,33(1):109-113
HY-2 satellite is the first satellite for dynamic environmental parameters measurement of China,which was launched on 16th August 2011.A scanning microwave radiometer（RM） is carried for sea surface temperature（SST）,sea surface wind speed,columnar water vapor and columnar cloud liquid water detection.In this paper,the initial SST product of RM was validated with in-situ data of National Data of Buoy Center（NDBC） mooring and Argo buoy.The validation results indicate the accuracy of RM SST is better than 1.7 C.The comparison of RM SST and WindSat SST shows the former is warmer than the latter at high sea surface wind speed and the difference between these SSTs is depend on the sea surface wind speed.Then,the relationship between the errors of RM SST and sea surface wind speed was analyzed using NDBC mooring measurements.Based on the results of assessment and errors analysis,the suggestions of taking account of the affection of sea surface wind speed and using sea surface wind speed and direction derived from the microwave scatteromter aboard on HY-2 for SST product calibration were given for retrieval algorithm improvement. 相似文献
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星载微波辐射计外定标的关键问题是通过辐射传输方程计算天线入瞳处亮温。根据辐射传输方程,海面成份对亮温的影响包括海面的微波辐射和对下行大气辐射的反射,其中的关键参数分别为海面发射率ep和海表面反射率R。文中对平静海面Fresnel反射率模式和粗糙海面反射率模式进行了研究分析,在此基础上着重研究了海面温度TS、海面盐度SS、海面风速W、以及观测角度θ等物理参数对海面发射率ep的影响,进而分析了这些物理参数的测量误差对亮温的计算精度的影响。 相似文献
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相比于实孔径微波辐射计,一维综合孔径微波辐射计具有高空间分辨率和多入射角观测特点。本文提出采用观测频率为6.9,10.65,18.7,23.8和36.5 GHz,且入射角范围为0°~65°的一维综合孔径微波辐射计遥感大气海洋环境要素。基于构建的微波大气海洋辐射传输正演模型,分析了辐射计亮温对大气海洋环境要素的敏感性,为辐射计关键指标确定和大气海洋环境要素反演算法设计提供技术支撑。结果表明：一维综合孔径微波辐射计的垂直和水平极化亮温对大气海洋环境要素的敏感性表现出不同特性,且敏感性随入射角的改变而变化显著;6.9和10.65 GHz对海面温度的敏感性较大,且随着入射角的增大,垂直极化亮温的敏感性增大,水平极化亮温的敏感性减小;10.65和18.7 GHz对海面风速的敏感性相对较大,且敏感性最大的风速区间位于10~20 m/s;23.8 GHz对大气水汽含量最敏感,且水汽含量较低、入射角较大时,敏感性越大;36.5 GHz对云液态水含量最敏感,随着入射角的增大,垂直极化亮温的敏感性减小,水平极化的敏感性增大,但两者均在液态水含量较小时表现出较大的敏感性。 相似文献
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基于一维综合孔径微波辐射计的海面温度反演研究 总被引：1，自引：0，他引：1
Due to the low spatial resolution of sea surface temperature(T_S) retrieval by real aperture microwave radiometers,in this study, an iterative retrieval method that minimizes the differences between brightness temperature(T_B)measured and modeled was used to retrieve sea surface temperature with a one-dimensional synthetic aperture microwave radiometer, temporarily named 1 D-SAMR. Regarding the configuration of the radiometer, an angular resolution of 0.43° was reached by theoretical calculation. Experiments on sea surface temperature retrieval were carried out with ideal parameters; the results show that the main factors affecting the retrieval accuracy of sea surface temperature are the accuracy of radiometer calibration and the precision of auxiliary geophysical parameters. In the case of no auxiliary parameter errors, the greatest error in retrieved sea surface temperature is obtained at low T_S scene(i.e., 0.710 6 K for the incidence angle of 35° under the radiometer calibration accuracy of0.5 K). While errors on auxiliary parameters are assumed to follow a Gaussian distribution, the greatest error on retrieved sea surface temperature was 1.330 5 K at an incidence angle of 65° in poorly known sea surface wind speed(W)(the error on W of 1.0 m/s) over high W scene, for the radiometer calibration accuracy of 0.5 K. 相似文献
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SARAL carried onboard a radar altimeter that provides very precise measurements of the sea surface height (SSH). Like other altimetric missions, SARAL carries a passive microwave radiometer (PMR) for wet tropospheric correction to SSH. In the present study, new algorithms are developed for the retrieval of cloud liquid water (CLW) and total precipitable water vapor (TPW) over the global oceans from PMR measurements of the brightness temperatures. A radiative transfer and genetic algorithm based retrieval scheme is proposed for the estimation of CLW and TPW from SARAL PMR. The comparisons of CLW from PMR with independent measurements from GPM-GMI and SSMIS within and outside ±40° latitudes show correlation (R) of 0.86 and 0.83, bias of 0.7 and ?3.61?mg/cm2, and root mean square error (RMSE) of 8.42 and 8.07?mg/cm2, respectively. Similarly, TPW from PMR with GPM-GMI and SSMIS show R of 0.99 and 0.98, bias of ?0.04 and ?0.03?g/cm2 and RMSE of 0.17 and 0.17?g/cm2, respectively. The retrieval accuracy of CLW and TPW from the new algorithms is compared with these parameters provided in the SARAL geophysical data records as finished products, which showed substantial improvement in the quality of the parameters from the new algorithm. 相似文献
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L. M. Mitnik M. L. Mitnik G. M. Chernyavsky I. V. Cherny A. V. Vykochko M. K. Pichugin E. V. Zabolotskikh 《Izvestiya Atmospheric and Oceanic Physics》2016,52(9):1041-1050
Application of satellite passive microwave sensing for the retrieval of key climatic parameters in the Barents Sea is considered. Fields of surface wind, atmosphere water vapor content and cloud liquid water content were found from MTVZA-GY radiometer onboard the Meteor-M N1 satellite and AMSR2 onboard the GCOM-W1 satellite with the use of original algorithms. The fields are in a good agreement with the ancillary remote and in situ measurements, which follows from the analysis of the evolution of the extra tropical and polar cyclones and cold air outbreaks with storm winds leading to intense air-sea interaction, and the formation and drift of sea ice. 相似文献