Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales
The potential of Global Navigation Satellite Systems-Reflectometry (GNSS-R) techniques to estimate land surface parameters such as soil moisture (SM) is experimentally studied using 2014⁻2017 global data from the UK TechDemoSat-1 (TDS-1) mission. The approach is based on the analysis of th...
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doaj-b7eb7b7523dc49f6a1abc31fb51740372020-11-25T00:40:27ZengMDPI AGRemote Sensing2072-42922018-11-011011185610.3390/rs10111856rs10111856Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial ScalesAdriano Camps0Mercedes Vall·llossera1Hyuk Park2Gerard Portal3Luciana Rossato4CommSensLab, Unidad de Excelencia María de Maeztu, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, E-08034 Barcelona, SpainCommSensLab, Unidad de Excelencia María de Maeztu, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, E-08034 Barcelona, SpainCommSensLab, Unidad de Excelencia María de Maeztu, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, E-08034 Barcelona, SpainCommSensLab, Unidad de Excelencia María de Maeztu, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, E-08034 Barcelona, SpainCommSensLab, Unidad de Excelencia María de Maeztu, Department of Signal Theory and Communications, Universitat Politècnica de Catalunya, E-08034 Barcelona, SpainThe potential of Global Navigation Satellite Systems-Reflectometry (GNSS-R) techniques to estimate land surface parameters such as soil moisture (SM) is experimentally studied using 2014⁻2017 global data from the UK TechDemoSat-1 (TDS-1) mission. The approach is based on the analysis of the sensitivity to SM of different observables extracted from the Delay Doppler Maps (DDM) computed by the Space GNSS Receiver⁻Remote Sensing Instrument (SGR-ReSI) instrument using the L1 (1575.42 MHz) left-hand circularly-polarized (LHCP) reflected signals emitted by the Global Positioning System (GPS) navigation satellites. The sensitivity of different GNSS-R observables to SM and its dependence on the incidence angle is analyzed. It is found that the sensitivity of the calibrated GNSS-R reflectivity to surface soil moisture is ~0.09 dB/% up to 30° incidence angle, and it decreases with increasing incidence angles, although differences are found depending on the spatial scale used for the ground-truth, and the region. The sensitivity to subsurface soil moisture has been also analyzed using a network of subsurface probes and hydrological models, apparently showing some dependence, but so far results are not conclusive.https://www.mdpi.com/2072-4292/10/11/1856soil moistureGNSS-Rsatellitehydrologymodelprobesensitivity |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Adriano Camps Mercedes Vall·llossera Hyuk Park Gerard Portal Luciana Rossato |
spellingShingle |
Adriano Camps Mercedes Vall·llossera Hyuk Park Gerard Portal Luciana Rossato Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales Remote Sensing soil moisture GNSS-R satellite hydrology model probe sensitivity |
author_facet |
Adriano Camps Mercedes Vall·llossera Hyuk Park Gerard Portal Luciana Rossato |
author_sort |
Adriano Camps |
title |
Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales |
title_short |
Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales |
title_full |
Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales |
title_fullStr |
Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales |
title_full_unstemmed |
Sensitivity of TDS-1 GNSS-R Reflectivity to Soil Moisture: Global and Regional Differences and Impact of Different Spatial Scales |
title_sort |
sensitivity of tds-1 gnss-r reflectivity to soil moisture: global and regional differences and impact of different spatial scales |
publisher |
MDPI AG |
series |
Remote Sensing |
issn |
2072-4292 |
publishDate |
2018-11-01 |
description |
The potential of Global Navigation Satellite Systems-Reflectometry (GNSS-R) techniques to estimate land surface parameters such as soil moisture (SM) is experimentally studied using 2014⁻2017 global data from the UK TechDemoSat-1 (TDS-1) mission. The approach is based on the analysis of the sensitivity to SM of different observables extracted from the Delay Doppler Maps (DDM) computed by the Space GNSS Receiver⁻Remote Sensing Instrument (SGR-ReSI) instrument using the L1 (1575.42 MHz) left-hand circularly-polarized (LHCP) reflected signals emitted by the Global Positioning System (GPS) navigation satellites. The sensitivity of different GNSS-R observables to SM and its dependence on the incidence angle is analyzed. It is found that the sensitivity of the calibrated GNSS-R reflectivity to surface soil moisture is ~0.09 dB/% up to 30° incidence angle, and it decreases with increasing incidence angles, although differences are found depending on the spatial scale used for the ground-truth, and the region. The sensitivity to subsurface soil moisture has been also analyzed using a network of subsurface probes and hydrological models, apparently showing some dependence, but so far results are not conclusive. |
topic |
soil moisture GNSS-R satellite hydrology model probe sensitivity |
url |
https://www.mdpi.com/2072-4292/10/11/1856 |
work_keys_str_mv |
AT adrianocamps sensitivityoftds1gnssrreflectivitytosoilmoistureglobalandregionaldifferencesandimpactofdifferentspatialscales AT mercedesvallllossera sensitivityoftds1gnssrreflectivitytosoilmoistureglobalandregionaldifferencesandimpactofdifferentspatialscales AT hyukpark sensitivityoftds1gnssrreflectivitytosoilmoistureglobalandregionaldifferencesandimpactofdifferentspatialscales AT gerardportal sensitivityoftds1gnssrreflectivitytosoilmoistureglobalandregionaldifferencesandimpactofdifferentspatialscales AT lucianarossato sensitivityoftds1gnssrreflectivitytosoilmoistureglobalandregionaldifferencesandimpactofdifferentspatialscales |
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1725290089962012672 |