0000000000118093

AUTHOR

Patrick J. Starks

showing 4 related works from this author

Assessment of the SMAP Level-4 Surface and Root-Zone Soil Moisture Product Using In Situ Measurements

2017

International audience; The Soil Moisture Active Passive (SMAP) mission Level-4 Surface and Root-Zone Soil Moisture (L4_SM) data product is generated by assimilating SMAP L-band brightness temperature observations into the NASA Catchment land surface model. The L4_SM product is available from 31 March 2015 to present (within 3 days from real time) and provides 3-hourly, global, 9-km resolution estimates of surface (0-5 cm) and root-zone (0-100 cm) soil moisture and land surface conditions. This study presents an overview of the L4_SM algorithm, validation approach, and product assessment versus in situ measurements. Core validation sites provide spatially averaged surface (root zone) soil m…

Atmospheric Science010504 meteorology & atmospheric sciences0208 environmental biotechnologyDrainage basin[SDU.STU]Sciences of the Universe [physics]/Earth SciencesSoil science02 engineering and technologyLand cover01 natural sciencesStandard deviationITC-HYBRIDData assimilationSoil temperatureWater content0105 earth and related environmental sciencesgeographygeography.geographical_feature_category020801 environmental engineeringSatellite observations[SDU]Sciences of the Universe [physics]Brightness temperatureITC-ISI-JOURNAL-ARTICLEData assimilationDNS root zoneEnvironmental scienceSoil moistureLand surface modelScale (map)Kalman filtersJournal of hydrometeorology
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An assessment of the differences between spatial resolution and grid size for the SMAP enhanced soil moisture product over homogeneous sites

2018

Abstract Satellite-based passive microwave remote sensing typically involves a scanning antenna that makes measurements at irregularly spaced locations. These locations can change on a day to day basis. Soil moisture products derived from satellite-based passive microwave remote sensing are usually resampled to a fixed Earth grid that facilitates their use in applications. In many cases the grid size is finer than the actual spatial resolution of the observation, and often this difference is not well understood by the user. Here, this issue was examined for the Soil Moisture Active Passive (SMAP) enhanced version of the passive-based soil moisture product, which has a grid size of 9-km and …

In situSpatial resolution010504 meteorology & atmospheric sciencesResolution (electron density)0211 other engineering and technologiesSoil ScienceGeology02 engineering and technologySMAPGrid01 natural sciencesIn situITC-ISI-JOURNAL-ARTICLE2023 OA procedureEnvironmental scienceSatelliteSoil moistureComputers in Earth SciencesAntenna (radio)Water contentImage resolutionScaling021101 geological & geomatics engineering0105 earth and related environmental sciencesRemote sensingRemote sensing of environment
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Validation of SMAP surface soil moisture products with core validation sites

2017

Abstract The NASA Soil Moisture Active Passive (SMAP) mission has utilized a set of core validation sites as the primary methodology in assessing the soil moisture retrieval algorithm performance. Those sites provide well-calibrated in situ soil moisture measurements within SMAP product grid pixels for diverse conditions and locations. The estimation of the average soil moisture within the SMAP product grid pixels based on in situ measurements is more reliable when location specific calibration of the sensors has been performed and there is adequate replication over the spatial domain, with an up-scaling function based on analysis using independent estimates of the soil moisture distributio…

010504 meteorology & atmospheric sciencesMean squared error0211 other engineering and technologiesSoil Science02 engineering and technology01 natural scienceslaw.inventionlawValidationCalibrationComputers in Earth SciencesRadarSpatial domainWater content021101 geological & geomatics engineering0105 earth and related environmental sciencesRemote sensingRadiometerPixelGeologySMAP22/4 OA procedureITC-ISI-JOURNAL-ARTICLEEnvironmental scienceSatelliteSoil moisture
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The SMAP mission combined active-passive soil moisture product at 9 km and 3 km spatial resolutions

2018

Abstract The NASA Soil Moisture Active Passive (SMAP) mission was launched on January 31st, 2015. The spacecraft was to provide high-resolution (3 km and 9 km) global soil moisture estimates at regular intervals by combining for the first time L-band radiometer and radar observations. On July 7th, 2015, a component of the SMAP radar failed and the radar ceased operation. However, before this occurred the mission was able to collect and process ~2.5 months of the SMAP high-resolution active-passive soil moisture data (L2SMAP) that coincided with the Northern Hemisphere's vegetation green-up and crop growth season. In this study, we evaluate the SMAP high-resolution soil moisture product deri…

National Snow and Ice Data CenterRadiometer010504 meteorology & atmospheric sciences0211 other engineering and technologiesNorthern HemisphereSoil ScienceGeology02 engineering and technologyVegetation01 natural sciencesActive passivelaw.inventionlawEnvironmental scienceProduct (category theory)Computers in Earth SciencesRadarWater content021101 geological & geomatics engineering0105 earth and related environmental sciencesRemote sensingRemote Sensing of Environment
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