2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad)最新文献

Comparison of retrieval algorithms for the wet tropospheric path delay 湿对流层路径延迟检索算法的比较

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878919

S. Thao, E. Obligis, B. Picard, M. Frery, L. Eymard

{"title":"Comparison of retrieval algorithms for the wet tropospheric path delay","authors":"S. Thao, E. Obligis, B. Picard, M. Frery, L. Eymard","doi":"10.1109/MICRORAD.2014.6878919","DOIUrl":"https://doi.org/10.1109/MICRORAD.2014.6878919","url":null,"abstract":"This paper provides a comparative analysis of statistical algorithms for the retrieval of the wet tropospheric correction from microwave radiometers in the context of altimetry missions. The algorithms are based on the algorithms used in Envisat and Jason-1 missions. The objective of this comparison is two-folds: 1) To find which regression method is better suited for the retrieval between the neural network algorithm and the log linear regression. 2) To tackle the problem of variable selection, i.e. to find the best set of variables to include as inputs in order to reduce the retrieval error. In particular, we want to determine whether the lack of a radiometer third channel at 18GHz can be compensated by the altimeter backscattering coefficient. Several configurations of algorithms, including those used in the operational processing of altimetry missions such as JASON-1 or ENVISAT, are built and compared on the same learning and test databases to determine which retrieval strategy is more appropriate. The database is composed of atmospheric and oceanographic conditions taken from the European Centre for Medium-Range Weather Forecasts (ECMWF) analyses and the brightness temperatures are simulated using a radiative transfer model. The importance of each input for the different algorithms is analyzed and the performances of the different algorithms are assessed in terms of error (bias and standard deviation) but also in terms of geographical distribution of the errors and correlation with other environmental variables. The results are then validated on Jason-2 radiometer measurements. Our results show that, in terms of variable selection, better results were obtained when the brightness temperature at 18 GHz was used instead of the backscattering coefficient. Moreover, better estimations of the wet tropospheric path delay were obtained with neural networks.","PeriodicalId":309298,"journal":{"name":"2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123709571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microwave Imager instrument for MetOp Second Generation MetOp第二代微波成像仪

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878948

S. D'addio, V. Kangas, U. Klein, M. Loiselet, G. Mason, A. Sacchetti, T. Lupi, C. Tabart, C. Bredin, F. Bayle, E. Vetrano, N. Sidiropoulos

引用次数: 5

Calibration efforts for MWR on-board SAC-D/Aquarius mission MWR星载SAC-D/Aquarius任务的校准工作

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878935

C. Bruscantini, M. Maas, F. Grings, H. Karszenbaum

{"title":"Calibration efforts for MWR on-board SAC-D/Aquarius mission","authors":"C. Bruscantini, M. Maas, F. Grings, H. Karszenbaum","doi":"10.1109/MICRORAD.2014.6878935","DOIUrl":"https://doi.org/10.1109/MICRORAD.2014.6878935","url":null,"abstract":"The Microwave Radiometer (MWR) on board the SACD/Aquarius mission, launched on June 2011, is a Dicke radiometer operating at 23.8 GHz (H-Pol) and 36.5 GHz (H/V/+45/-45-Pol). MWR channels are useful to provide ancillary data for the various retrievals to be performed with Aquarius regarding ocean and land applications. In this study we report the calibration results obtained by a land cross-calibration between Windsat and MWR. Results were generated for the 2011-2012 period and using the version V5.0S of the MWR data. Radiometer inter-comparison over selected homogeneous targets is widely used for calibration assessment and data quality evaluation. The methodology lays on the temporal stability of the selected targets and their homogeneity in terms of brightness temperature (Tb), so that radiometers with similar characteristics (frequency, polarization, incidence angle) should observe the same Tb when passing over the target within a short temporal window. Differences on observed Tbs are associated to a poor calibration of the instrument under study. The cross-calibration is an adjustment of the Tb data of the radiometer under study to match the Tb data of the already calibrated radiometer. In this study, linear adjustments are applied for each MWR beams of its three channels to match Windsat observations. In order to examine the entire dynamic range of land observations, 19 homogeneous targets were selected for cross-calibration. These targets have been previously selected for quality assessment of AMSR-E data [1]. Targets include tropical and boreal forests, desert, grassland and Sahel. Overall, it was found that the instrument compares favorably toWindsat over land targets. Nevertheless, certain issues to be resolved are identified and corrections are proposed.","PeriodicalId":309298,"journal":{"name":"2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128325907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Aquarius salinity retrieval algorithm recent progress and remaining challenges Aquarius盐度检索算法的最新进展和存在的挑战

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878906

T. Meissner, F. Wentz, L. Ricciardulli, K. Hilburn, J. Scott

引用次数: 8

Efficient deconvolution and spatial resolution enhancement from continuous and oversampled observations in microwave imagery 微波图像连续和过采样观测的有效反褶积和空间分辨率增强

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878929

I. Yanovsky, A. Tanner, B. Lambrigtsen

引用次数: 8

Inter-comparison of SMOS and aquarius Sea Surface Salinity: Effects of the dielectric constant and vicarious calibration SMOS与aquarius海水表面盐度的比较:介电常数和替代校准的影响

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878907

E. Dinnat, J. Boutin, X. Yin, D. L. Le Vine

{"title":"Inter-comparison of SMOS and aquarius Sea Surface Salinity: Effects of the dielectric constant and vicarious calibration","authors":"E. Dinnat, J. Boutin, X. Yin, D. L. Le Vine","doi":"10.1109/MICRORAD.2014.6878907","DOIUrl":"https://doi.org/10.1109/MICRORAD.2014.6878907","url":null,"abstract":"Two spaceborne instruments share the scientific objective of mapping the global Sea Surface Salinity (SSS). ESA's Soil Moisture and Ocean Salinity (SMOS) and NASA's Aquarius use L-band (1.4 GHz) radiometry to retrieve SSS. We find that SSS retrieved by SMOS is generally lower than SSS retrieved by Aquarius, except for very cold waters where SMOS SSS is higher overall. The spatial distribution of the differences in SSS is similar to the distribution of sea surface temperature. There are several differences in the retrieval algorithm that could explain the observed SSS differences. We assess the impact of the dielectric constant model and the ancillary sea surface salinity used by both missions for calibrating the radiometers and retrieving SSS. The differences in dielectric constant model produce differences in SSS of the order of 0.3 psu and exhibit a dependence on latitude and temperature. We use comparisons with the Argo in situ data to assess the performances of the model in various regions of the globe. Finally, the differences in the ancillary sea surface salinity products used to perform the vicarious calibration of both instruments are relatively small (0.1 psu), but not negligible considering the requirements for spaceborne remote sensing of SSS.","PeriodicalId":309298,"journal":{"name":"2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124076166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Radiometer based measurements of slant-path attenuation in the V/W bands 基于辐射计的V/W波段倾斜路径衰减测量

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878921

G. Brost, K. Magde, W. Cook

引用次数: 5

Microwave Sounder instrument for MetOp Second Generation MetOp第二代微波测深仪

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878947

V. Kangas, S. D'addio, M. Loiselet, G. Mason, M. Buckley, G. Tennant, P. Campbell

引用次数: 7

Radiometric inter-calibration of SAPHIR using the Microwave Humidity Sounders 利用微波湿度测深仪对sapir进行辐射互定

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878942

H. Ebrahimi, S. Datta, A. Santos-Garcia, L. Jones

引用次数: 9

Land surface microwave emissivity dynamics: Observations, analysis and modeling 陆地表面微波发射率动力学:观测、分析和模拟

2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad) Pub Date : 2014-03-24 DOI: 10.1109/MICRORAD.2014.6878917

Yudong Tian, C. Peters-Lidard, K. Harrison, Sujay V. Kumar, S. Ringerud

{"title":"Land surface microwave emissivity dynamics: Observations, analysis and modeling","authors":"Yudong Tian, C. Peters-Lidard, K. Harrison, Sujay V. Kumar, S. Ringerud","doi":"10.1109/MICRORAD.2014.6878917","DOIUrl":"https://doi.org/10.1109/MICRORAD.2014.6878917","url":null,"abstract":"Land surface microwave emissivity affects remote sensing of both the atmosphere and the land surface. The dynamical behavior of microwave emissivity over a very diverse sample of land surface types is studied. With seven years of satellite measurements from AMSR-E, we identified various dynamical regimes of the land surface emission. In addition, we used two radiative transfer models (RTMs), the Community Radiative Transfer Model (CRTM) and the Community Microwave Emission Modeling Platform (CMEM), to simulate land surface emissivity dynamics. With both CRTM and CMEM coupled to NASA's Land Information System, global-scale land surface microwave emissivities were simulated for five years, and evaluated against AMSR-E observations. It is found that both models have successes and failures over various types of land surfaces. Among them, the desert shows the most consistent underestimates (by ~70-80%), due to limitations of the physical models used, and requires a revision in both systems. Other snow-free surface types exhibit various degrees of success and it is expected that parameter tuning can improve their performances.","PeriodicalId":309298,"journal":{"name":"2014 13th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment (MicroRad)","volume":"974 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123078598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0