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Retrieval of soil moisture from passive and active L/S band sensor (PALS) observations during the soil moisture experiment in 2002 (SMEX) / U. Narayan in Remote sensing of environment, vol 92 n° 4 (30 September 2004)
[article]
Titre : Retrieval of soil moisture from passive and active L/S band sensor (PALS) observations during the soil moisture experiment in 2002 (SMEX) Type de document : Article/Communication Auteurs : U. Narayan, Auteur ; V. Lakshmi, Auteur ; E. Njoku, Auteur Année de publication : 2004 Article en page(s) : pp 483 - 496 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande L
[Termes IGN] bande S
[Termes IGN] bande spectrale
[Termes IGN] capteur actif
[Termes IGN] capteur passif
[Termes IGN] Glycine max
[Termes IGN] humidité du sol
[Termes IGN] Iowa (Etats-Unis)
[Termes IGN] maïs (céréale)
[Termes IGN] Passive and Active L and S band Sensor
[Termes IGN] régression
[Termes IGN] Soil Moisture Experiment
[Termes IGN] teneur en eau de la végétation
[Termes IGN] transfert radiatifRésumé : (Auteur) The Soil Moisture Experiments in 2002 (SMEX02) were conducted in Iowa between June 25th and July 12th, 2002. A major aim of the experiments was examination of existing algorithms for soil moisture retrieval from active and passive microwave remote sensors under high vegetation water content conditions. The data obtained from the passive and active L and S band sensor (PALS) along with physical variables measured by in situ sampling have been used in this study to demonstrate the sensitivity of the instrument to soil moisture and perform soil moisture retrieval using statistical regression and physical modeling techniques. The land cover conditions in the region studied were predominantly soybean and corn crops with average vegetation water contents ranging from 0 to ~ 5 kg/m2. The PALS microwave sensitivity to soil moisture under these vegetation conditions was investigated for both passive and active measurements. The performance of the PALS instrument and retrieval algorithms has been analyzed, indicating soil moisture retrieval errors of approximately 0.04 g/g gravimetric soil moisture. Statistical regression techniques have been shown to perform satisfactorily with soil moisture retrieval error of around 0.05 g/g gravimetric soil moisture. The retrieval errors were higher for the corn than for the soybean fields due to the higher vegetation water content of the corn crops. However, the algorithms performed satisfactorily over the full range of vegetation conditions. Numéro de notice : A2004-414 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.05.018 En ligne : https://doi.org/10.1016/j.rse.2004.05.018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26941
in Remote sensing of environment > vol 92 n° 4 (30 September 2004) . - pp 483 - 496[article]SMEX02: field scale variability, time stability and similarity of soil moisture / J.M. Jacobs in Remote sensing of environment, vol 92 n° 4 (30 September 2004)
[article]
Titre : SMEX02: field scale variability, time stability and similarity of soil moisture Type de document : Article/Communication Auteurs : J.M. Jacobs, Auteur ; B.P. Mohanty, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 436 - 446 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse diachronique
[Termes IGN] Argile
[Termes IGN] bassin hydrographique
[Termes IGN] flore locale
[Termes IGN] humidité du sol
[Termes IGN] Iowa (Etats-Unis)
[Termes IGN] pente
[Termes IGN] point de vérification
[Termes IGN] précision
[Termes IGN] Soil Moisture Experiment
[Termes IGN] stabilité dans le tempsRésumé : (Auteur) Evaluation of air- or space-bome remote sensors measuring soil moisture requires strategic ground-based sampling. As part of the Soil Moisture Experiment 2002 (SMEX02), daily surface soil moisture sampling at 90-140 locations were conducted in four fields in Walnut Creek watershed, Iowa. Various combinations of soils, vegetation, and topography characterize the fields. Depending on the field's characteristics and soil moisture content, 3 - 32 independent measurements were necessary to capture the field mean volumetric soil moisture with a + 2% bias and 95% confidence interval. Validation of the retrieved soil moisture products from the aircraft microwave instruments using the average of 14 samples per field is more appropriate for dry (25% volumetric soil moisture) range than for intermediate soil moisture range. Time stability analysis showed that an appropriately selected single sampling point could provide similar accuracy across a range of soil moisture conditions. Analyses based on landscape position (depression, hilltop, steep slope, and mild slope) showed that locations with mild slopes consistently exhibit time stable features. Hilltop and steep slope locations consistently underestimated mean field soil moisture. Soils parameters could not be used to identify time stable features as sampling locations with relatively high sand content consistently underestimated the field mean while those locations with relatively high clay content consistently overestimated the field mean. However, the slope position characterization of time stable features was enhanced using soils properties. The mild slope locations having the best time-stable features are those with moderate to moderately high clay content as compare to the field average (28-30% clay). Numéro de notice : A2004-413 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.02.017 En ligne : https://doi.org/10.1016/j.rse.2004.02.017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26940
in Remote sensing of environment > vol 92 n° 4 (30 September 2004) . - pp 436 - 446[article]Watershed scale temporal and spatial stability of soil moisture and its role in validating satellite estimates / M.H. Cosh in Remote sensing of environment, vol 92 n° 4 (30 September 2004)
[article]
Titre : Watershed scale temporal and spatial stability of soil moisture and its role in validating satellite estimates Type de document : Article/Communication Auteurs : M.H. Cosh, Auteur ; Thomas J. Jackson, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 427 - 435 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Advanced Microwave Scanning Radiometer
[Termes IGN] analyse comparative
[Termes IGN] bassin hydrographique
[Termes IGN] étalonnage des données
[Termes IGN] humidité du sol
[Termes IGN] Iowa (Etats-Unis)
[Termes IGN] ligne de partage des eaux
[Termes IGN] limite de résolution géométrique
[Termes IGN] Soil Moisture ExperimentRésumé : (Auteur) Watershed scale soil moisture estimates are necessary to validate current remote sensing products, such as those from the Advanced Microwave Scanning Radiometer (AMSR). Unfortunately, remote sensing technology does not currently resolve the land surface at a scale that is easily observed with ground measurements. One approach to validation is to use existing soil moisture measurement networks and scale these point observations up to the resolution of remote sensing footprints. As part of the Soil Moisture Experiment 2002 (SMEX02), one such soil moisture gaging system in the Walnut Creek Watershed, Iowa, provided robust estimates of the soil moisture average for a watershed throughout the summer of 2002. Twelve in situ soil moisture probes were installed across the watershed. These probes recorded soil moisture at a depth of 5 cm from June 29, 2002 to August 19, 2002. The sampling sites were analyzed for temporal and spatial stability by several measures including mean relative difference, Spearman rank, and correlation coefficient analysis. Representative point measurements were used to estimate the watershed scale (3 25 km) soil moisture average and shown to be accurate indicators with low variance and bias of the watershed scale soil moisture distribution. This work establishes the validity of this approach to provide watershed scale soil moisture estimates in this study region for the purposes of satellite validation with estimation errors as small as 3%. Also, the potential sources of error in this type of analysis are explored. This study is a first step in the implementation of large-scale soil moisture validation using existing networks such as the Soil Climate Analysis Network (SCAN) and several Agricultural Research Service watersheds as a basis for calibrating satellite soil moisture products, for networks design, and designing field experiments. Numéro de notice : A2004-412 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.02.016 En ligne : https://doi.org/10.1016/j.rse.2004.02.016 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26939
in Remote sensing of environment > vol 92 n° 4 (30 September 2004) . - pp 427 - 435[article]Monitoring surface soil moisture in post-harvest rice areas using C-band radar imagery in NorthEast Thailand / S. Kaojarern in Geocarto international, vol 19 n° 3 (September - November 2004)
[article]
Titre : Monitoring surface soil moisture in post-harvest rice areas using C-band radar imagery in NorthEast Thailand Type de document : Article/Communication Auteurs : S. Kaojarern, Auteur ; Thuy Le Toan, Auteur ; M.W. Davidson, Auteur Année de publication : 2004 Article en page(s) : pp 61 - 71 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] agriculture
[Termes IGN] bande C
[Termes IGN] humidité du sol
[Termes IGN] image ERS-SAR
[Termes IGN] image radar
[Termes IGN] image Radarsat
[Termes IGN] rizière
[Termes IGN] seuillage d'image
[Termes IGN] surveillance agricole
[Termes IGN] surveillance météorologique
[Termes IGN] ThaïlandeRésumé : (Auteur) The objective of this study is to estimate the residual surface soil moisture of rice fields after harvesting, in Northeast Thailand, using Cband SAR images. Such information is use 1 to determine possibilities of cultivating additional shortcycle crops after the harvesting of the main rice crop. To accomplish this objective this study exploits three Cband SAR images acquired over the test area along with simultaneous ground measurements collected in support of analysis of the SAR images. The main parameters measured on the ground were: the volumetric moisture content of the soil using time domain reflectrometry (TDR), the surface roughness, using profile data, and residue cover. Other field environmental factors that might affect radar backscattering, including the topography of rice terraces (elevation, slope, and aspect), bund height between rice fields, soil types, and density of sparse tree stands were also acquired and registered to the image data. Before the analysis, the SAR images were calibrated, registered, and then filtered using multitemporal and spatial filters to reduce variability of the radar backscattering coefficient due to speckle. The measured soil moisture values were then correlated with the radar backscattering coefficients of the experimental plots and the results interpreted in terms of the main environmental factors. Varying residue cover and field aspect angles were found to significantly affect the relationship between radar backscatter and soil moisture content and therefore had to be taken into account before inverting the image data into soil moisture maps. Overall it was found that two soil moisture classes could reliably be separated using the SAR images, and that soil moisture maps could be obtained through a simple inversion technique based on applying a threshold to the SAR images. Analyses of these resulting moisture maps indicate that SAR data is useful to monitor and map surface soil moisture in rice fields after harvest. Numéro de notice : A2004-479 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040408542319 Date de publication en ligne : 02/01/2008 En ligne : https://doi.org/10.1080/10106040408542319 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26997
in Geocarto international > vol 19 n° 3 (September - November 2004) . - pp 61 - 71[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-04031 RAB Revue Centre de documentation En réserve L003 Disponible Design and test of the ground-based L-band radiometer for estimating water in soils (LEWIS) / F. LemaÎtre in IEEE Transactions on geoscience and remote sensing, vol 42 n° 8 (August 2004)
[article]
Titre : Design and test of the ground-based L-band radiometer for estimating water in soils (LEWIS) Type de document : Article/Communication Auteurs : F. LemaÎtre, Auteur ; J.C. Poussiere, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 1666 - 1676 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] étalonnage d'instrument
[Termes IGN] humidité du sol
[Termes IGN] L-band radiometer for Estimating Water In Soils
[Termes IGN] performance
[Termes IGN] radiomètre
[Termes IGN] Soil Moisture and Ocean Salinity Mission
[Termes IGN] température de luminanceRésumé : (Auteur) In the framework of the preparation of the Soil Moisture and Ocean Salinity (SMOS) mission, several field experiments are required so as to address specific modeling issues. The goal is to improve current models and to test retrieval algorithms. However, adequate ground instrumentation is scarce and not readily available "off the shelf": In this context, a high-accuracy L-band radiometer was required for a specific long-term campaign for the preparation of the SMOS mission. For this purpose, a dual-polarized radiometer was designed and built to check algorithms for surface soil moisture retrieval from multiangular dual-polarized brightness temperatures. This radiometer has been tested in the field for 20 months and is operational since end of January 2003. The aim of this paper is to give details of the system architecture, calibration procedures, together with the performances obtained and some preliminary results. Numéro de notice : A2004-427 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.831230 En ligne : https://doi.org/10.1109/TGRS.2004.831230 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26954
in IEEE Transactions on geoscience and remote sensing > vol 42 n° 8 (August 2004) . - pp 1666 - 1676[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-04081 RAB Revue Centre de documentation En réserve L003 Disponible A phase signature for detecting wet subsurface structures using polarimetric L-band SAR / Y. Lasne in IEEE Transactions on geoscience and remote sensing, vol 42 n° 8 (August 2004)PermalinkMapping groundwater level and depth in the Azraq Basin in Jordan using GIS / R.A. Al-Adamat in Surveying and land information science, vol 64 n° 2 (01/06/2004)PermalinkAssessing the potential of space-borne C-band SAR data for spatial soil moisture information over a large area / S.A. Romshoo in Geocarto international, vol 19 n° 1 (March - May 2004)PermalinkLooking after water in Africa / J. Achache in ESA bulletin, n° 117 (February 2004)PermalinkEffectiveness of spectroscopy in identification of swelling indicator clay minerals / P.C. Kariuki in International Journal of Remote Sensing IJRS, vol 25 n° 2 (January 2004)PermalinkImpacts of hydrologic soil properties on drought detection with MODIS thermal data / S. Park in Remote sensing of environment, vol 89 n° 1 (15/01/2004)PermalinkThe EuroSTARRS airborne campaign in support of the SMOS mission: first results over land surfaces / K. Saleh in International Journal of Remote Sensing IJRS, vol 25 n° 1 (January 2004)PermalinkVisualisation graphique WinMarthe / V. Hussenet (2004)PermalinkVegetation canopy anisotropy at 1.4 GHz / B.K. Hornbuckle in IEEE Transactions on geoscience and remote sensing, vol 41 n° 10 (October 2003)PermalinkIntegrating interferometric SAR data with levelling measurements of land subsidence using geostatistic / Y. Zhou in International Journal of Remote Sensing IJRS, vol 24 n° 18 (September 2003)Permalink