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Satellite air temperature estimation for monitoring the canopy layer heat island of Milan

REMOTE SENSING OF ENVIRONMENT 2012年 127卷 130-138页

作者： Pichierri, Manuele Bonafoni, Stefania Biondi, Riccardo Univ Perugia Dept Elect & Informat Engn I-06125 Perugia Italy Natl Space Inst DTU Space DK-2100 Copenhagen O Denmark

In this work, satellite maps of the urban heat island of Milan are produced using satellite-based infrared sensor data. For this aim, we developed suitable algorithms employing satellite brightness temperatures for the direct air temperature estimation 2 m above the surface (canopy layer), showing accuracies below 2 K. The air temperatures measured by ground-based weather stations were properly matched with brightness temperatures observed by the Moderate-resolution Imaging Spectroradiometer (MODIS) on board of both Terra and Aqua satellites. In total, 931 daytime and nighttime scenes taken between 2007 and 2010 were processed. Analysis of the canopy layer heat island (CLHI) maps during summer months reveals an average heat island effect of 3-4 K during nighttime (with some peaks around 5 K) and a weak CLHI intensity during daytime. In addition, the satellite maps reveal a well defined island shape across the city center from June to September confirming that, in Milan, urban heating is not an occasional phenomenon. Furthermore, this study shows the utility of space missions to monitor the metropolis heat islands if they are able to provide nighttime observations when CLHI peaks are generally significant. (c) 2012 Elsevier Inc. All rights reserved.

关键词： Canopy layer heat island Satellite-based sensor Air temperature retrieval algorithm

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Assessment of total suspended sediment concentrations in Poyang Lake using HJ-1A/1B CCD imagery

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Chinese Journal of Oceanology and Limnology 2012年第2期30卷 295-304页

作者：于之锋陈晓玲周斌田礼乔袁小红冯炼 State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing(LIESMARS)Wuhan University Institute of Remote Sensing and Earth Sciences Hangzhou Normal University Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of EducationJiangxi Normal University

We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m, revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake, the largest freshwater lake in China, as an example. Field surveys conducted during October 17-26, 2009 showed a wide range of TSS concentration (3-524 mg/L). Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys, which worked well at the CCD bands with relatively high reflectance. A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration. The retrieved results for the whole water area matched the in-situ data well at most stations. The retrieval errors may be related to the problem of scale matching and mixed pixel. In three selected subregions of Poyang Lake, the distribution trend of retrieved TSS was consistent with that of the field investigation. It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm.

关键词： total suspended sediment HJ-1A/1B CCD atmospheric correction retrieval algorithm Poyang Lake

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Ku-Band Radar Altimeter Surface Wind Speed algorithm

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MARINE GEODESY 2012年第sup1期35卷 276-298页

作者： Abdalla, S. European Ctr Medium Range Weather Forecasts Reading RG2 9AX Berks England

A surface wind speed retrieval algorithm from Ku-band radar altimeter backscatter coefficients is presented. It was derived using two-months of ENVISAT altimeter backscatter data collocated with ECMWF model and in situ wind speeds and was extensively verified for ENVISAT, ERS-2, and Jason-1/2 against model and in situ wind data. The algorithm performs better than the two-parameter (backscatter and significant wave height, SWH) algorithms of Jason-1/2. The success of the current algorithm raises a question regarding the usefulness of SWH alone as a second parameter for retrievals. It is argued that SWH alone is not the proper choice to represent the sea-state conditions.

关键词： Atmospheric model backscatter ECMWF Envisat ERS-2 Jason radar altimeter retrieval algorithm significant wave height verification wind speed

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Parametric representation of soil isoline equation and its accuracy estimation in red-NIR reflectance space

Parametric representation of soil isoline equation and its a...

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Conference on Land Surface Remote Sensing

作者： Taniguchi, Kenta Ikuta, Yasuhiro Obata, Kenta Matsuoka, Masayuki Yoshioka, Hiroki Aichi Prefectural Univ Dept Informat Sci & Technol 1522-3 Ibara Nagakute Aichi 4801198 Japan Univ Hawaii Dept Nat Resources & Environm Management Honolulu HI 96822 USA Kochi Univ Nat Sci Cluster Nanko Ku Kochi 7838502 Japan

ISBN: (纸本)9780819492630

retrieval of biophysical parameters from remotely sensed reflectance spectra often involves algebraic manipulations, e. g. spectral vegetation index, to enhance pure signals from a target of one's interest. An underlying assumption of those processes is an existence of high correlation between an obtained value from the manipulations and amount of the target object. These correlations can be seen in scatter plots of reflectance spectra as isolines that represent a relationship between two reflectances of different wavelengths (bands) under constant values of physical parameters. Therefore, modeling the isolines would contribute to better understanding of retrieval algorithms and eventually to improve their accuracies. The objective of this study is to derive one such relationship observed under a constant spectrum of soil surfaces, known as soil isolines, in red-NIR reflectance space. This work introduces a parametric representation of the soil isolines (soil isoline equation) with the parameter obtained by rotating the red-NIR reflectance space by approximately a quarter of pi radian counter clockwise. The accuracy in the soil isoline equation depends on the order of polynomials used for the representations: It was investigated numerically by conducting experiments with radiative transfer models for vegetation canopy. The results showed that when the first-order approximation were employed for both bands, the accuracy of the parametric representations/approximations of the soil isolines is approximately 0.02 in terms of mean absolute difference from the simulated spectra (with no approximation). The accuracies improved dramatically when one retains the polynomial terms up to the second-order or higher for both bands.

关键词： Soil Isoline Equation Biophysical Parameter retrieval algorithm Vegetation Isoline Equation

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RETRIEVING ATMOSPHERIC TEMPERATURE AND MOISTURE PROFILES FROM SUOMI NPP CRIS/ATMS SENSORS USING CRIMSS EDR algorithm

RETRIEVING ATMOSPHERIC TEMPERATURE AND MOISTURE PROFILES FRO...

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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Liu, X. Kizer, S. Barnet, C. Divakarla, M. Gu, D. Zhou, D. K. Larar, A. M. Xiong, X. Guo, G. Nalli, N. R. Gambacorta, A. Wilson, M. Blackwell, W. Zhou, L. Ma, X. Goldberg, M. Tobin, D. NASA Langley Res Ctr Hampton VA 23681 USA

ISBN: (纸本)9781467311595

As a part of the Joint Polar Satellite System (JPSS) and the Suomi National Polar-orbiting Partnership (NPP), the Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments make up the Cross-track Infrared and Microwave Sounder Suite (CrIMSS). CrIMSS primarily provides globally-referenced calibrated radiances and vertical profiles of temperature, moisture, and pressure.. The CrIMSS operational code has been ported to various LINUX systems and retrievals are performed using both proxy and real ATMS/CrIS data. The high quality proxy data generated from the IASI instrument provided useful testing for the CrIMSS EDR algorithm prior to the launch of the SUOMI NPP satellite. The experience learned from processing the proxy data helped us to handle the SUOMI NPP CrIS/ATMS data as soon as they became available to the CAL/VAL team. In this paper, encouraging preliminary results of applying the ported CrIMSS EDR algorithm to the SUOMI NPP CrIS/ATMS data are presented.

关键词： retrieval algorithm EDR CrIS ATMS IASI CrIMSS NPP atmospheric sounding

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An inversion algorithm for retrieval of aerosol optical and physical properties from ground-based solar and sky radiance

An inversion algorithm for retrieval of aerosol optical and ...

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4th International Symposium on Photoelectronic Detection and Imaging (ISPDI) - Advances in Infrared Imaging and Applications

作者： Qie Lili Xu Qingshan Wei Heli Chinese Acad Sci Key Lab Atmospher Composit & Opt Radiat Anhui Inst Opt & Fine Mech Hefei 230031 Anhui Peoples R China

ISBN: (纸本)9780819488343

An inversion algorithm has been developed for retrieving a set of parameters of aerosol scattering and microphysical properties from POM02 sky-radiometer measurements. POM01/02 is the main observation instrument of Skynet. It's designed to measure solar and sky irradiance with waveband ranging from visible to infrared, as well as the measurement of polarization sky radiance at 870nm wavelength. Teruyuki Nakajima developed a software package to analyze its observation data named SKYRAD. pack. SKYRAD. pack code can retrieve the columnar aerosol features, such as optical depth, single-scattering albedo, phase function and size distribution, provided the input parameters, such as complex refractive index and ground albedo, are correctly given. In our algorithm, most of aerosol key characteristics, including single-scattering albedo, phase function, polarized phase function at 870nm, complex refractive index, and size distribution, are retrieved from direct and scattered solar irradiance as well as polarized sky radiance at 870nm, by using a polarized radiative transfer code RT3. This method requires only measurement of the aerosol's optical thickness and an estimate of the ground's reflectance and does not need any specific assumption about properties of the aerosol. The preliminary results are reported in the paper.

关键词： Aerosol property Polarization retrieval algorithm

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A Retrieving algorithm for Unfolded Sheet Metal Parts Based on the Features Relationship

A Retrieving Algorithm for Unfolded Sheet Metal Parts Based ...

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Asia Simulation Conference/International Conference on System Simulation and Scientific Computing (AsiaSim and ICSC 2012)

作者： Wang, Dawei Ge, Dongyun COMAC Beijing Aeronaut Sci & Technol Res Inst BASTR Beijing 102211 Peoples R China

ISBN: (纸本)9783642343957

This paper presents a new retrieval algorithm for unfolded sheet metal parts. The primary idea of this novel algorithm is based on the relative position relationships of features in sheet metal parts. After analyzing the data structure of sheet metal parts, some kinds of key features are abstracted and the relative position model is described to express the difference of features' relative position. Further, detailed information about the position model and the formula of similarity developed for difficult sheet metal parts is given and described. Also an example is given at the last of paper to verify the validity of our algorithm. Obviously, our new algorithm meets the requirements of searching unfolded sheet metal parts.

关键词： feature retrieval algorithm sheet metal CAD

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Toward a robust retrieval of snow accumulation over the Antarctic ice sheet using satellite radar

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JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 2012年第D9期117卷

作者： Dierking, W. Linow, S. Rack, W. Alfred Wegener Inst Polar & Marine Res Climate Sci Div D-27570 Bremerhaven Germany Univ Canterbury Ctr Antarctic Studies & Res Christchurch 1 New Zealand

The sensitivity of radar measurements to snow accumulation rate is determined by the firn volume characteristics of the ice sheets. Here we present a new approach for calculating the volume backscattering of dry firn, which is combined with recently developed empirical parameterizations of firn grain size and density as functions of depth, surface temperature, and accumulation rate. To this end, dense medium radiative transfer theory is applied to calculate the volume scattering and absorption coefficients. The coefficients for the density transition between snow and dense firn are evaluated using polynomial interpolation. For testing the method, we used measured accumulation rates, Envisat ASAR C-band wide-swath mode images, and QuikSCAT Ku-band backscattering data from Dronning Maud Land, Antarctica. The comparison between measured and simulated backscattering coefficients shows that no tuning parameter is necessary to obtain the correct absolute level of scattering intensity. The robustness of accumulation rate retrievals depends on the consideration of technical and environmental factors. Due to the presence of sastrugi on the ice sheet surface the measured intensities are sensitive to the radar look direction. Wind compaction of snow and depth hoar formation change the depth-dependent snow density and grain size profiles. Theoretical simulations revealed that the backscattering coefficient at C-band is more sensitive to changes of accumulation rates than at Ku-band. Penetration depths can vary significantly, dependent on radar frequency and firn characteristics. This has to be taken into account when comparing accumulation rates from different locations.

关键词： dense medium ice sheets radar backscattering remote sensing retrieval algorithm snow accumulation

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RETRIEVING ATMOSPHERIC TEMPERATURE AND MOISTURE PROFILES FROM SUOMI NPP CRIS/ATMS SENSORS USING CRIMSS EDR algorithm

RETRIEVING ATMOSPHERIC TEMPERATURE AND MOISTURE PROFILES FRO...

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IEEE International Geoscience and Remote Sensing Symposium

作者： X. Liu S. Kizer C. Barnet M. Divakarla D. Gu D. K. Zhou A. M. Larar X. Xiong G. Guo N. R. Nalli A. Gambacorta M. Wilson W. Blackwell L. Zhou X. Ma M. Goldberg D. Tobin NASA Langley Research Center Science Systems and Applications Inc. NOAA Center for Satellite Applications and Research IM Systems Group Inc. Northrop Grumman Aerospace Systems Riverside Technology inc. MIT Lincoln Laboratory University of Wisconsin-Madison

ISBN: (纸本)9781467311601

As a part of the Joint Polar Satellite System (JPSS) and the Suomi National Polar-orbiting Partnership (NPP), the Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instruments make up the Cross-track Infrared and Microwave Sounder Suite (CrIMSS). CrIMSS primarily provides globally-referenced calibrated radiances and vertical profiles of temperature, moisture, and pressure. The CrIMSS operational code has been ported to various LINUX systems and retrievals are performed using both proxy and real ATMS/CrIS data. The high quality proxy data generated from the IASI instrument provided useful testing for the CrIMSS EDR algorithm prior to the launch of the SUOMI NPP satellite. The experience learned from processing the proxy data helped us to handle the SUOMI NPP CrIS/ATMS data as soon as they became available to the CAL/VAL team. In this paper, encouraging preliminary results of applying the ported CrIMSS EDR algorithm to the SUOMI NPP CrIS/ATMS data are presented.

关键词： retrieval algorithm EDR CrIS ATMS IASI CrIMSS NPP Atmospheric sounding Nuclear powerplants POMC Gene Proxy Vertical profiles atmospheric temperature Acoustic generators Moisture LAUNCHING preliminary data retrieval Sensors

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SOIL MOISTURE retrieval FROM DENSE TEMPORAL SERIES OF C-BAND SAR DATA OVER AGRICULTURAL SITES

SOIL MOISTURE RETRIEVAL FROM DENSE TEMPORAL SERIES OF C-BAND...

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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Balenzano, Anna Satalino, Giuseppe Pauwels, Valentijn Mattia, Francesco CNR ISSIA I-70126 Bari Italy Univ Ghent LHWM Ghent Belgium

ISBN: (纸本)9781457710056

This paper investigates the use of dense time series of C-band SAR data (i.e. acquired with revisit time within 1-2 weeks) for the retrieval of volumetric soil moisture content (m(nu)) underneath agricultural crops. Its final aim is to contribute at assessing retrieval strategies for monitoring agricultural areas using near future frequent-revisit SAR missions, such as the forthcoming European Sentinel-1. A recently developed m(nu) retrieval algorithm is firstly presented and then applied to a time series of ASAR HH and HV data collected in 2006 over the agricultural DEMMIN site (Germany). The assessment of the algorithm is provided by comparing the SAR-derived m(nu) maps over the DEMMIN site with hydrologically modelled m(nu) maps. Results indicate that m(nu) can be retrieved with accuracy ranging between 5% and 6%.

关键词： Sentinel-1 soil moisture retrieval algorithm Synthetic Aperture Radar (SAR) hydrology

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