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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Mitnik, Leonid M. Gurvich, Irina A. Pichugin, Mikhail K. VI Ilichev Pacific Oceanol Inst FEB RAS Vladivostok 690041 Russia

ISBN: (纸本)9781457710056

Mesoscale cyclonic activity is one of the characteristics of the cold season in the Japan Sea. High winds and precipitation accompanying intense mesoscale cyclones (MCs) disturb transport and fishery operations in the sea and small sizes and fast development hinders their forecast and detection. Satellite data of visible, infrared, passive and active microwave sensors serve as a valuable source of data on MCs. They are used for their detection, tracking, evaluating of quantitative characteristics of the atmospheric and oceanic parameters during MC life cycle, getting statistical estimates as well as for checking and improving the results of modeling. Case studies demonstrate the efficiency of the multisensory approach and the leading role of microwave sensing for mesoscale cyclone investigation.

关键词： mesoscale cyclones passive microwave sensing Aqua AMSR-E retrieval algorithms Japan Sea

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Thermodynamic state retrieval from microwave occultation data and performance analysis based on end-to-end simulations

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JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 2011年第D10期116卷 1D,2D,3D,4D,5D,6D,7D,8D,9D,10D,11D,12D,13D,14D,15D,16D,17D,18D,19D页

作者： Schweitzer, S. Kirchengast, G. Schwaerz, M. Fritzer, J. Gorbunov, M. E. Graz Univ Wegener Ctr Climate & Global Change A-8010 Graz Austria Graz Univ Inst Geophys Astrophys & Meteorol Inst Phys A-8010 Graz Austria Russian Acad Sci Inst Atmospher Phys Moscow Russia

Microwave occultation using centimeter- and millimeter-wave signals between low Earth orbit (LEO) satellites (LEO microwave occultation, LMO) is an advancement of GPS radio occultation (GRO) exploiting in addition to refraction also absorption of signals. Beyond the successful GRO refractivity profiling capability, which leaves a temperature-humidity ambiguity in the troposphere where moisture cannot be neglected, LMO enables joint retrieval of pressure, temperature, and humidity profiles without auxiliary background information. Here we focus on the upper troposphere/lower stratosphere and advance the LMO method in two ways: (1) we introduce a new retrieval algorithm for processing LMO excess phase and amplitude data from multiple frequencies, complementing existing GRO retrieval algorithms, and (2) we employ the algorithm in an ensemble-based end-to-end performance analysis and assess the accuracy of pressure, temperature, and humidity profiles retrieved from the LMO data. The end-to-end simulations were carried out under quasi-realistic conditions for a day of LEO-LEO occultation events, based on a high-resolution atmospheric analysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) and accounting for scintillation noise from turbulence and instrumental errors. The new algorithm was found robust, fast, and versatile to adequately process LMO data under all conditions from dry and clear to moist and cloudy air as contained in the ECMWF analysis. The retrieved pressure, temperature, and humidity profiles were generally found unbiased and within target accuracy requirements, set by scientific objectives of atmosphere and climate research going to be supported by the data, of <0.2% (pressure), <0.5 K (temperature), and <10% (humidity). Extending a "minimum" LMO design with three frequencies near 22 GHz with two added frequencies near 183 GHz favorably provides humidity retrieval into the lower stratosphere but already the "minimum" design resolves th

关键词： atmospheric remote sensing microwave occultation thermodynamic state climate benchmarking retrieval algorithms end-to-end simulations

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Sea State Parameters Extraction from Radar Images:System Design and Implementation

Sea State Parameters Extraction from Radar Images:System Des...

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2011 CIE International Conference on Radar(RADAR 2011)

作者： Ding Hao,Huang Yong,Song Jie,Guan Jian,He You (Research Institute of Information Fusion,Naval Aeronautical and Astronautical University,Yantai,264001,China)

The main concentration of this paper is the system design and implementation of sea state parameters retrieval technique from nautical radar. The system consists of three main components:a general sea clutter data acquisition subsystem, a standard computer and a software package. The data acquisition subsystem is designed to acquire sea clutter data and then form consecutive image sequence for further analysis. The standard computer stores the acquired data and offers a hardware platform for the entire system. The software package with program language of Visual C++ fulfills the realization of the retrieval algorithms. Experimental results show the effectiveness and feasibility of the research. This work has significant values not only for ocean engineering but also for the performance of radar system in the detection of dim targets in strong sea clutter.

关键词： Sea state parameters sea clutter data acquisition system retrieval algorithms dim targets detection

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The development of new algorithms for remote sensing of snow conditions based on data from the catchment of vre Heimdalsvatn and the vicinity

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HYDROBIOLOGIA 2010年第1期642卷 35-46页

作者： Solberg, Rune Koren, Hans Amlien, Jostein Malnes, Eirik Schuler, Dagrun Vikhamar Orthe, Nils Kristian Norwegian Comp Ctr NR N-0314 Oslo Norway No Res Inst Norut N-9294 Tromso Norway Norwegian Meteorol Inst N-0313 Oslo Norway Norwegian Water Resources & Energy Directorate NVE N-0301 Oslo Norway

The catchment of vre Heimdalsvatn and the surrounding area was established as a site for snow remote sensing algorithm development, calibration and validation in 1997. Information on snow cover and snowmelt are important for understanding the timing and scale of many lake ecosystem processes. Field campaigns combined with data from airborne sensors and spaceborne high-resolution sensors have been used as reference data in experiments over many years. Several satellite sensors have been utilised in the development of new algorithms, including Terra MODIS and Envisat ASAR. The experiments have been motivated by operational prospects for snow hydrology, meteorology and climate monitoring by satellite-based remote sensing techniques. This has resulted in new time-series multi-sensor approaches for monitoring of snow cover area (SCA) and snow surface wetness (SSW). The idea was to analyse, on a daily basis, a time series of optical and radar satellite data in multi-sensor models. The SCA algorithm analyses each optical and synthetic aperture radar (SAR) image individually and combines them into a day product based on a set of confidence functions. The SSW algorithm combines information about the development of the snow surface temperature and the snow grain size (SGS) in a time-series analysis. The snow cover algorithm is being evaluated for application in a global climate monitoring system for snow variables. The successful development of these algorithms has led to operational applications of snow monitoring in Norway and Sweden, as well as enabling the prediction of the spring snowmelt flood and thus the initiation of many lake production processes.

关键词： Remote sensing retrieval algorithms Fractional snow cover Snow surface wetness Snow surface temperature

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Estimation of the polarized water leaving radiance from above water measurements

Estimation of the polarized water leaving radiance from abov...

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Conference on Ocean Sensing and Monitoring II

作者： Tonizzo, A. Ibrahim, A. Zhou, J. Gilerson, A. Twardowski, M. Gross, B. Moshary, F. Ahmed, S. The City College of New York (United States) WET Labs. Inc. (United States)

ISBN: (纸本)9780819481429

An acquisition system was developed to measure the above water polarized radiance. This system consists of one irradiance sensor for downwelling irradiance, one radiance sensor oriented at 40 degrees from the zenith to measure sky radiance and three radiance sensors looking down at 40 degrees from the nadir to measure above water radiance. In order to obtain the polarized radiance, polarizers with orientation of 0 degrees, 90 degrees and 45 degrees respectively were placed in front of the three radiance sensors. The whole system was installed on the bow of the boat for continuous observations of above water polarized radiance along the ship's track during a recent cruise in the NY Bight area. Water optical properties were measured by an optical package towed from a small R/V. In order to obtain the degree of polarization (DOP) of the water body, the contribution of the sky radiance must be first removed and this process has to be done for all components of the Stokes vector. Using a model employing the polarized Fresnel coefficients of the interface the polarized component of reflection is estimated from the direct measurement of sky radiance and downwelling irradiance data. These components are then subtracted from the measured values to obtain the water contribution. The DOP of the ocean body is then related to the in - water IOPs.

关键词： Remote sensing ocean water optical properties polarization retrieval algorithms

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Hydros Soil Moisture retrieval algorithms: Status and Relevance to Future Missions

Hydros Soil Moisture Retrieval Algorithms: Status and Releva...

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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： O'Neill, Peggy Owe, Manfred Gouweleeuw, Ben Njoku, Eni Shi, J. C. Wood, Eric NASA Goddard Space Flight Ctr Hydrol Sci Branch Code 614-3 Greenbelt MD 20771 USA NASA Jet Prop Lab Pasadena CA 91109 USA Univ Calif Santa Barbara Santa Barbara CA 93106 USA Princeton Univ Dept Civil & Environm Engn Princeton NJ 08854 USA

ISBN: (纸本)9780780395091

In 2002 the Hydrosphere State Mission (Hydros) was selected by NASA as the alternate mission for a flight opportunity under its Earth System Science Pathfinder program. The Hydros mission objective was to collect the first global scale measurements of the Earth's soil moisture and land surface freeze/thaw conditions, using a combined L band radiometer and radar system operating at 1.41 and 1.26 GHz, respectively. Although NASA cancelled the Hydros mission in December 2005 due to insufficient funding and its reversion back to alternate mission status, the development of accurate soil moisture retrieval algorithms and associated error analyses begun under the Hydros project are still relevant to SMOS and to other potential future soil moisture missions.

关键词： soil moisture Hydros retrieval algorithms microwave radiometry error budget

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MICROWAVE SOIL MOISTURE retrieval UNDER TREES USING A MODIFIED TAU-OMEGA MODEL

MICROWAVE SOIL MOISTURE RETRIEVAL UNDER TREES USING A MODIFI...

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IEEE International Geoscience and Remote Sensing Symposium

作者： O'Neill, Peggy Lang, Roger Kurum, Mehmet Joseph, Alicia Cosh, Michael Jackson, Thomas NASA Goddard Space Flight Ctr Hydrol Sci Branch Code 614-3 Greenbelt MD 20771 USA George Washington Univ Dept Elect & Comp Engn Washington DC 20052 USA USDA ARS Hydrol & Remote Sensing Lab Beltsville MD 20705 USA

ISBN: (纸本)9781424433940

During 2007-2009 field experiments have been conducted using the ComRAD microwave truck instrument system with a goal of optimizing microwave soil moisture retrieval algorithms for small to medium deciduous and coniferous trees. A joint effort of NASA / GSFC and George Washington University, ComRAD consists of a quad-polarized 1.25 GHz radar and a dual-polarized 1.4 GHz radiometer sharing the same antenna. In the current study, ComRAD microwave data and ground truth measurements of soil moisture, temperature, soil texture, and vegetation water content and geometry statistics have been used to assess whether the zero-order tau-omega model can be employed successfully to retrieve soil moisture under tree canopies using effective values for tau (the vegetation opacity) and omega (the single scattering albedo). In addition, the tau-omega model has been modified to include a first-order scattering term, which will be discussed in a companion paper [1].

关键词： soil moisture retrieval algorithms microwave radiometry trees tau-omega model

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A VEGETATION CORRECTION METHODOLOGY APPLIED FOR SOIL MOISTURE retrieval FROM C-BAND RADAR OBSERVATIONS

A VEGETATION CORRECTION METHODOLOGY APPLIED FOR SOIL MOISTUR...

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IEEE International Geoscience and Remote Sensing Symposium

作者： Joseph, A. T. van der Velde, R. O'Neill, P. E. Lang, R. Gish, T. NASA Goddard Space Flight Ctr Hydrol Sci Branch 614 3 Hydrospher & Biospher Sci Lab Greenbelt MD 20771 USA Int Inst Geo Informat Sci & Earth & Observat ITC Enschede Netherlands George Washington Univ Dept Elect & Comp Sci Washington DC 20052 USA USDA ARS Hydrol & Remote Sensing Lab Beltsville MD 20705 USA

ISBN: (纸本)9781424433940

This research presents a methodology to correct backscatter (sigma(0)) observations for vegetation effects. The proposed methodology is based on the concept that the ratio between the surface scattering over the total amount of scattering (sigma(0)(surface)/sigma(0)(soil)) is affected only by the vegetation and can be described as a function of the vegetation water content. The data set used in this study was collected at USDA's Optimizing Production Inputs for Economic and Environmental Enhancement (OPE3) experimental site in Beltsville, Maryland (USA) over a corn growth cycle in 2002 and includes C-band (4 75 GHz) HH- and VV-polarized observations acquired at incidence angles of 15, 35 and 55 degrees During this period the corn crops reached peak biomass of 6.6 kg m(-2) and a soil moisture range varying from 0.02 to 0.26 cm(3)cm(-3) The results show that through application of the proposed vegetation correction methodology the soil moisture retrieval accuracy can be improved from 0.033 to 0 032 cm(3)cm(-3), 0.049 to 0 033 cm(3)cm(-3), and 0.079 to 0 047 cm(3)cm(-3) at incidence angles of 15, 35 and 55 degrees, respectively

关键词： Vegetation correction soil moisture radar retrieval algorithms

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Systems engineering analysis of a TRMM PR-like rainfall retrieval algorithm

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2007年第2期45卷 426-434页

作者： Rose, C. R. Chandrasekar, V. Los Alamos Natl Lab Los Alamos NM 87545 USA Colorado State Univ Ft Collins CO 80523 USA

Systems engineering constitutes a group of processes and methods to design and implement a system for optimal performance given limited time, technology, or resources. As with any system, it is important to understand which subcomponents are most important and which are less important so that appropriate resource allocations may be made. An example of a complex system is the Tropical Rainfall Measuring Mission (TRMM). Its subsystems include the satellite vehicle, the precipitation radar (YR), the ground validation system, and the retrieval algorithms. Each of these subsystems contributes to the overall success of the mission. Sensitivity analysis (SA) is a method whereby the output response from a model can be linked back to the variability in the input parameters. This paper describes a method of performing SA on a TRMM PR-like (TL) rainfall retrieval algorithm (based on the TRMM 2A25 algorithm) to better describe how the uncertainty in the model output can be apportioned to the uncertainty in the input factors and gain greater understanding as to the relative importance of each factor. For example, assuming a model with several input factors, if one factor is found to be the dominating cause of model error, and the others contribute relatively little, then resources can be devoted to improving the accuracy of one factor, thereby improving the overall model accuracy. This paper is based on global SA using a variance decomposition technique. Analyses are done and results are presented for factor importance for cases over both ocean and land. Results for the simple TL algorithm considered in this paper show that at low rain rate, the a and b coefficients in the R = aZ(e)(b) relationship contribute the greatest amount to the output variance. At higher rain rates, above about 8 mm/h, the error from Delta sigma degrees is the greatest contributor to error in algorithm output.

关键词： drop size distribution (DSD) retrieval retrieval algorithms sensitivity analysis spaceborne retrieval systems engineering Tropical Rainfall Measuring Mission (TRMM)

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Radiative transfer model MCC plus plus with evaluation of weighting functions in spherical atmosphere for use in retrieval algorithms

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TRACE CONSTITUENTS IN THE TROPOSPHERE AND LOWER STRATOSPHERE 2004年第4期34卷 721-+页

作者： Postylyakov, OV RAS AM Obukhov Inst Atmospher Res Moscow 119017 Russia

A linearized radiative transfer model MCC++ designed for use in retrieval algorithms was developed. It calculates the weighting functions with respect to the absorption in all atmospheric layers and the layer air mass factors simultaneously with the intensities. Multiple scattering radiance is calculated by the Monte Carlo methods for spherical atmosphere taking into account the polarization of light, aerosol loading of atmosphere and the Lambertian surface albedo. A validation of the MCC++ model against other radiative transfer models is presented. It includes a comparison of weighting function calculations, a comparison for the scattering limb geometry, a comparison for twilight ground-based observations. As an example, additional errors of Brewer Umkehr retrieval algorithms, when they use the weighting functions calculated for approximation of single-scattering, are evaluated. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

关键词： radiative transfer model for spherical atmosphere multiple scattering weighting functions air mass factors inverse problems retrieval algorithms

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