Sea Surface Salinity Products Validation Based on Triple Match Method

Since satellites have observed the sea surface temperature (SSS) from space for years, the scientific community has devoted many efforts to the validation of satellite SSS products. Typically, this validation procedure is based on the “double match” method between the in situ a...

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Main Authors: Jin Wang, Weifu Sun, Jie Zhang
Format: Article
Language:English
Published: IEEE 2019-01-01
Series:IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Subjects:
Online Access:https://ieeexplore.ieee.org/document/8879531/
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author Jin Wang
Weifu Sun
Jie Zhang
author_facet Jin Wang
Weifu Sun
Jie Zhang
author_sort Jin Wang
collection DOAJ
description Since satellites have observed the sea surface temperature (SSS) from space for years, the scientific community has devoted many efforts to the validation of satellite SSS products. Typically, this validation procedure is based on the &#x201C;double match&#x201D; method between the in situ and remote-sensed measurements. However, this direct comparison has its limitations because it does not take into account sampling error of different SSS sources. Actually, the in situ method presents the pointwise measurements and the satellite data are the spatial average within its footprint, so the in situ data contain the true small-scale SSS signal which cannot be resolved by satellite data. Researchers introduce the representativeness error to describe the small-scale signal. However, the estimation of representativeness error remains challenging. In this study, based on the constancy of salinity variance, we develop a new method to estimate the representativeness error and apply it to the triple collocation dataset of Argo data and L3 SSS product of soil moisture active/passive (SMAP) and soil moisture and ocean salinity (SMOS). The representativeness error is estimated to be 0.093 psu<sup>2</sup> in global oceans. The random error of Argo data is better than 0.21 psu which is superior to SMAP and SMOS. Considering the different sampling resolution of SMAP and SMOS, the quality of SMAP SSS product (0.33 psu) is slightly better than SMOS (0.41 psu).
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spelling doaj.art-1b83ebb972764da1bd460eccd61972a52022-12-21T20:04:48ZengIEEEIEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing2151-15352019-01-0112114361436610.1109/JSTARS.2019.29454868879531Sea Surface Salinity Products Validation Based on Triple Match MethodJin Wang0https://orcid.org/0000-0001-5061-3532Weifu Sun1Jie Zhang2College of physics, Center for Marine observation and communications, Qingdao University, Qingdao, ChinaFirst Institute of Oceanography of the Ministry of Natural Resources of China, Qingdao, ChinaFirst Institute of Oceanography of the Ministry of Natural Resources of China, Qingdao, ChinaSince satellites have observed the sea surface temperature (SSS) from space for years, the scientific community has devoted many efforts to the validation of satellite SSS products. Typically, this validation procedure is based on the &#x201C;double match&#x201D; method between the in situ and remote-sensed measurements. However, this direct comparison has its limitations because it does not take into account sampling error of different SSS sources. Actually, the in situ method presents the pointwise measurements and the satellite data are the spatial average within its footprint, so the in situ data contain the true small-scale SSS signal which cannot be resolved by satellite data. Researchers introduce the representativeness error to describe the small-scale signal. However, the estimation of representativeness error remains challenging. In this study, based on the constancy of salinity variance, we develop a new method to estimate the representativeness error and apply it to the triple collocation dataset of Argo data and L3 SSS product of soil moisture active/passive (SMAP) and soil moisture and ocean salinity (SMOS). The representativeness error is estimated to be 0.093 psu<sup>2</sup> in global oceans. The random error of Argo data is better than 0.21 psu which is superior to SMAP and SMOS. Considering the different sampling resolution of SMAP and SMOS, the quality of SMAP SSS product (0.33 psu) is slightly better than SMOS (0.41 psu).https://ieeexplore.ieee.org/document/8879531/Representativeness errorsea surface salinitysoil moisture active/passive (SMAP)SMOStriple match
spellingShingle Jin Wang
Weifu Sun
Jie Zhang
Sea Surface Salinity Products Validation Based on Triple Match Method
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Representativeness error
sea surface salinity
soil moisture active/passive (SMAP)
SMOS
triple match
title Sea Surface Salinity Products Validation Based on Triple Match Method
title_full Sea Surface Salinity Products Validation Based on Triple Match Method
title_fullStr Sea Surface Salinity Products Validation Based on Triple Match Method
title_full_unstemmed Sea Surface Salinity Products Validation Based on Triple Match Method
title_short Sea Surface Salinity Products Validation Based on Triple Match Method
title_sort sea surface salinity products validation based on triple match method
topic Representativeness error
sea surface salinity
soil moisture active/passive (SMAP)
SMOS
triple match
url https://ieeexplore.ieee.org/document/8879531/
work_keys_str_mv AT jinwang seasurfacesalinityproductsvalidationbasedontriplematchmethod
AT weifusun seasurfacesalinityproductsvalidationbasedontriplematchmethod
AT jiezhang seasurfacesalinityproductsvalidationbasedontriplematchmethod