166 Hits in 3.4 sec

Rain-flagging of the Envisat altimeter

G.D. Quartly, M.A. Srokosz
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477)  
A dual-frequency rain detection technique developed for the K u -and C-band TOPEX altimeter, is adapted for the K u -and S-band RA-2 altimeter on Envisat.  ...  As the goals for altimetric measurements become ever more precise, there is concern about the reliable detection and discarding of rain contaminated data.  ...  ACKNOWLEDGMENTS This study used data provided to the RA2/MWR Cross-Calibration Validation Team by CLS, with additional waveform data disseminated by Jerome Benveniste (ESA).  ... 
doi:10.1109/igarss.2003.1294655 fatcat:j3kypiqctfh63hzwpgm2pn2p24

Validation of Jason and Envisat Altimeter Dual Frequency Rain Flags

2004 Marine Geodesy  
New rain flags based on the dual frequency capabilities of the new Jason Poseidon-2 and Envisat RA2 altimeters have been tested, developed and adopted for the operational processing of the altimeter data  ...  The results show a very good agreement between the two sensors and the two rain flags The Envisat flag is validated by comparison with both Jason and TOPEX using global and collocated data sets.  ...  Envisat A direct comparison of the rain flagging between Envisat and Topex/Jason is not possible because of the limited size of the collocated data sets.  ... 
doi:10.1080/01490410490465616 fatcat:nb42oxsvy5d6lcms3655du4t3y

Validation of Envisat Rain Detection and Rain Rate Estimates by Comparing With TRMM Data

Ngan Tran, Jean Tournadre, Pierre Femenias
2008 IEEE Geoscience and Remote Sensing Letters  
This letter provides validation results on both Envisat altimeter rain detection flag and rain rate estimates.  ...  This assessment was performed based on 18-month collocated data sets between Envisat with two sensor measurements from the Tropical Rainfall Measuring Mission, i.e., the microwave imager and the precipitation  ...  ACKNOWLEDGMENT The authors would like to thank the Goddard Space Flight Center Distributed Active Archive Center for the straightforward and rapid access via ftp to the TRMM data.  ... 
doi:10.1109/lgrs.2008.2002043 fatcat:jmd7zqvgafdztmocas5f2zr2nu

Validation of AltiKa Matching Pursuit Rain Flag

J. Tournadre, J. C. Poisson, N. Steunou, B. Picard
2015 Marine Geodesy  
A new rain flag based on the analysis of the altimeter measurement alone has thus been developed for AltiKa.  ...  AltiKa being a single frequency altimeter and this kind of simple and efficient flag could obviously not be utilized.  ...  The DWT can be regarded as an approximation of the CWT over a so-called dyadic grid of scales.  ... 
doi:10.1080/01490419.2014.1001048 fatcat:lvpo354ws5bw7cjmwncouscqf4

Monitoring Level Fluctuations of the Lakes in the Yangtze River Basin from Radar Altimetry

Yonghai Chu, Jiancheng Li, Weiping Jiang, Xiancai Zou, Chunbo Fan, Xinyu Xu, Isaac Dadzie
2008 Terrestrial, Atmospheric and Oceanic Sciences  
The results of this study, which is the first of its kind in using data from ENVISAT missions over the Yangtze River basin in China, reveal that the water level changes in these four lakes directly reflect  ...  the water level of the Yangtze River and contribute to the floods and their associated disasters that usually occur in the middle and lower reaches of the Yangtze River.  ...  The authors are also grateful to the ENVISAT data provided by ESA.  ... 
doi:10.3319/tao.2008.19.1-2.63(sa) fatcat:pxw3e6kto5apnkkdpkjjl7xrhu

Observing and Studying Extreme Low Pressure Events with Altimetry

Loren Carrère, Françoise Mertz, Joel Dorandeu, Yves Quilfen, Jerome Patoux
2009 Sensors  
In the case of Extra-Tropical Depressions, the classical altimeter processing can be used. Ocean signal not related to atmospheric pressure is along-track filtered.  ...  The S-and C-band measurements are used because they are less impacted by rain than the Ku-band, and new sea state bias (SSB) and wet troposphere corrections are proposed.  ...  The points with the ice flag, the land flag and the S-band anomaly set on are still eliminated.  ... 
doi:10.3390/s90301306 pmid:22573955 pmcid:PMC3345817 fatcat:hrmoauqlu5d2nid6htuxvuxpaq

Envisat Ocean Altimetry Performance Assessment and Cross-calibration

Yannice Faugere, Joël Dorandeu, Fabien Lefevre, Nicolas Picot, Pierre Femenias
2006 Sensors  
, assessment of the Envisat altimeter system performances.  ...  This paper presents the main results in terms of Envisat data quality: verification of data availability and validity, monitoring of the most relevant altimeter (ocean1 retracking) and radiometer parameters  ...  Acknowledgements This work has been funded by ESA through ENVISAT F-PAC activities. The quality assessment activities described in this paper are embedded in the CNES SSALTO.  ... 
doi:10.3390/s6030100 fatcat:exzi7el6j5ehbh54hfqpjwl5vi

A satellite altimeter model for ocean slick detection

J. Tournadre, B. Chapron, N. Reul, D. C. Vandemark
2006 Journal of Geophysical Research  
On the basis of the experience gained through the analysis of highresolution altimeter waveforms in the presence of rain cell, a model is developed to analyze the altimeter response to phenomena whose  ...  The analysis of high data rate altimeter waveforms during bloom events reveals the presence of V-shaped patterns similar to the ones observed during rain events.  ...  The Sensor Data Records encessary for the study were provided by the AVISO Centre.  ... 
doi:10.1029/2005jc003109 fatcat:t7kljliqtjepva3ninmasw5dgq

Validation of Significant Wave Height from Satellite Altimeter in the Seas around Korea and Error Characteristics

Kyung-Ae Park, Hye-Jin Woo, Eun-Young Lee, Sungwook Hong, Kum-Lan Kim
2013 Korean Journal of Remote Sensing  
Therefore, the waves at local coastal stations Abstract : Significant Wave Height (SWH) data measured by satellite altimeters (Topex/Poseidon, Jason-1, Envisat, and Jason-2) were validated in the seas  ...  A total of 1,070 collocation matchups between Ku-band satellite altimeter data and buoy data were obtained for the periods of the four satellites from 1992 to the present.  ...  This study was also supported in part by EAST-I project of the Ministry of Oceans and Fisheries, Korea. We are very grateful to the unknown reviewers for their helpful comments.  ... 
doi:10.7780/kjrs.2013.29.6.6 fatcat:aphvtonl2neihpfgbqebt45leq

Cloud and Rain Effects on AltiKa/SARAL Ka-Band Radar Altimeter—Part II: Definition of a Rain/Cloud Flag

J. Tournadre, J. Lambin-Artru, N. Steunou
2009 IEEE Transactions on Geoscience and Remote Sensing  
The use of a single channel for Altika prevents the use of the classical dual-frequency rain flag used for Topex or Jason altimeters, and requires the definition of a new flag based on the altimeter signal  ...  Index Terms-Ka-band altimeter, rain and cloud impact, rain/cloud flag.  ...  For these dual frequency altimeters rain flags, based on the differential attenuation of the main (Ku-band) and secondary channels (C-band for Topex and Jason-1 and S-band for Envisat) by rain droplets  ... 
doi:10.1109/tgrs.2008.2010127 fatcat:lcbieonlmrbxfjjowodwbf5geq

Introduction to the Special Issue on "Satellite Altimetry: New Sensors and New Applications"

Graham Quartly, Ge Chen
2006 Sensors  
[16] provide a thorough assessment of the first three years of Envisat data, showing that the proportions of data flagged and the r.m.s. uncertainties remained roughly constant over that period, and  ...  Finally, Zhang and Chen [17] consider maps of sea surface height anomaly produced separately for the four altimeters (Envisat, GFO, Jason-1 and TOPEX) flying during March 2004 to Feb 2005.  ... 
doi:10.3390/s6060616 fatcat:ngzef35pj5b5dgammiy62jrgfe

A coastally improved global dataset of wet tropospheric corrections for satellite altimetry

Clara Lázaro, Maria Joana Fernandes, Telmo Vieira, Eliana Vieira
2020 Earth System Science Data  
Additionally, GPD+ recovers the WTC for a significant number of along-track altimeter points with missing or invalid MWR-derived WTCs, due to land, rain and ice contamination and instrument malfunctioning  ...  The most accurate WPDs for RA are derived from the on-board microwave radiometer (MWR) radiance measurements, acquired simultaneously as the altimeter ranges.  ...  The authors thank the Radar Altimeter Database System (RADS) for providing the GPD+ input altimeter data for all missions except Envisat and SARAL up to cycle 30, Aviso+ (  ... 
doi:10.5194/essd-12-3205-2020 fatcat:el6z2otjbzd2nmx3535iwgs2qi

Overview of the ICESat Mission

B. E. Schutz, H. J. Zwally, C. A. Shuman, D. Hancock, J. P. DiMarzio
2005 Geophysical Research Letters  
[16] provide a thorough assessment of the first three years of Envisat data, showing that the proportions of data flagged and the r.m.s. uncertainties remained roughly constant over that period, and  ...  the disadvantages (greater sensitivity to clouds and rain).  ... 
doi:10.1029/2005gl024009 fatcat:itynrsycp5ae3jagomzqzk3sda

Altimeter dual-frequency observations of surface winds, waves, and rain rate in tropical cyclone Isabel

Y. Quilfen, J. Tournadre, B. Chapron
2006 Journal of Geophysical Research  
The most recent altimeters (Topex/Poseidon, Envisat, Jason-1) are dual-frequency altimeters to correct for ionospheric effects, but the dualfrequency capability has also been used to detect and flag measurements  ...  Section 4 presents the methodology to retrieve, along the altimeter track, the rain rate and the wind speed corrected for rain effects.  ...  This study was supported by the European Space Agency in the frame of the "Retrieval of extreme low surface pressure using altimeters" and "Extreme Weather Events" projects.  ... 
doi:10.1029/2005jc003068 fatcat:wn33ozcnarg43ikgyblc5gdhzi

Effect of Long Waves on Ku-Band Ocean Radar Backscatter at Low Incidence Angles Using TRMM and Altimeter Data

Ngan Tran, B. Chapron, D. Vandemark
2007 IEEE Geoscience and Remote Sensing Letters  
The observations come from satellite crossovers 8 of the Tropical Rainfall Mapping Mission (TRMM) precipita-9 tion radar (PR) and two satellite altimeters, namely: 1) Ja-10 son-1 and 2) Environmental Satellite  ...  impact 20 changes with incidence angle, and that it will affect the retrieval of 21 wind speed from σ 0 .  ...  The 427 authors would also like to thank two anonymous reviewers 428 whose comments helped improve the clarity of the document. 429  ... 
doi:10.1109/lgrs.2007.896329 fatcat:2o4nrsawtzdanl4a43eqwph5qq
« Previous Showing results 1 — 15 out of 166 results