Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements
Soil moisture products acquired from passive satellite missions have been widely applied in environmental processes. A primary challenge for the use of soil moisture products from passive sensors is their reliability. It is crucial to evaluate the reliability of those products before they can be rou...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2017-01-01
|
| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2072-4292/9/2/104 |
| _version_ | 1828437345192378368 |
|---|---|
| author | Xuefei Zhang Tingting Zhang Ping Zhou Yun Shao Shan Gao |
| author_facet | Xuefei Zhang Tingting Zhang Ping Zhou Yun Shao Shan Gao |
| author_sort | Xuefei Zhang |
| collection | DOAJ |
| description | Soil moisture products acquired from passive satellite missions have been widely applied in environmental processes. A primary challenge for the use of soil moisture products from passive sensors is their reliability. It is crucial to evaluate the reliability of those products before they can be routinely used at a global scale. In this paper, we evaluated the Soil Moisture Active/Passive (SMAP) and the Advanced Microwave Scanning Radiometer (AMSR2) radiometer soil moisture products against in situ measurements collected from American networks with four statistics, including the mean difference (MD), the root mean squared difference (RMSD), the unbiased root mean square error (ubRMSE) and the correlation coefficient (R). The evaluation results of SMAP and AMSR2 soil moisture products were compared. Moreover, the triple collocation (TC) error model was used to assess the error among AMSR2, SMAP and in situ data. The monthly average and daily AMSR2 and SMAP soil moisture data were analyzed. Different spatial series, temporal series and combined spatial-temporal analysis were carried out. The results reveal that SMAP soil moisture retrievals are generally better than AMSR2 soil moisture data. The remotely sensed retrievals show the best agreement with in situ measurements over the central Great Plains and cultivated crops throughout the year. In particular, SMAP soil moisture data shows a stable pattern for capturing the spatial distribution of surface soil moisture. Further studies are required for better understanding the SMAP soil moisture product. |
| first_indexed | 2024-12-10T19:43:48Z |
| format | Article |
| id | doaj.art-e607d033b55d463cb5b7334a09a2eeb9 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-10T19:43:48Z |
| publishDate | 2017-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-e607d033b55d463cb5b7334a09a2eeb92022-12-22T01:35:57ZengMDPI AGRemote Sensing2072-42922017-01-019210410.3390/rs9020104rs9020104Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based MeasurementsXuefei Zhang0Tingting Zhang1Ping Zhou2Yun Shao3Shan Gao4Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, ChinaInstitute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, ChinaSchool of Earth Science and Resource, China University of Geosciences, Beijing 100083, ChinaInstitute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, ChinaSchool of Land Science and Technology, China University of Geosciences, Beijing 100083, ChinaSoil moisture products acquired from passive satellite missions have been widely applied in environmental processes. A primary challenge for the use of soil moisture products from passive sensors is their reliability. It is crucial to evaluate the reliability of those products before they can be routinely used at a global scale. In this paper, we evaluated the Soil Moisture Active/Passive (SMAP) and the Advanced Microwave Scanning Radiometer (AMSR2) radiometer soil moisture products against in situ measurements collected from American networks with four statistics, including the mean difference (MD), the root mean squared difference (RMSD), the unbiased root mean square error (ubRMSE) and the correlation coefficient (R). The evaluation results of SMAP and AMSR2 soil moisture products were compared. Moreover, the triple collocation (TC) error model was used to assess the error among AMSR2, SMAP and in situ data. The monthly average and daily AMSR2 and SMAP soil moisture data were analyzed. Different spatial series, temporal series and combined spatial-temporal analysis were carried out. The results reveal that SMAP soil moisture retrievals are generally better than AMSR2 soil moisture data. The remotely sensed retrievals show the best agreement with in situ measurements over the central Great Plains and cultivated crops throughout the year. In particular, SMAP soil moisture data shows a stable pattern for capturing the spatial distribution of surface soil moisture. Further studies are required for better understanding the SMAP soil moisture product.http://www.mdpi.com/2072-4292/9/2/104soil moistureSMAPin situAMSR2triple collocation (TC)statistics |
| spellingShingle | Xuefei Zhang Tingting Zhang Ping Zhou Yun Shao Shan Gao Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements Remote Sensing soil moisture SMAP in situ AMSR2 triple collocation (TC) statistics |
| title | Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements |
| title_full | Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements |
| title_fullStr | Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements |
| title_full_unstemmed | Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements |
| title_short | Validation Analysis of SMAP and AMSR2 Soil Moisture Products over the United States Using Ground-Based Measurements |
| title_sort | validation analysis of smap and amsr2 soil moisture products over the united states using ground based measurements |
| topic | soil moisture SMAP in situ AMSR2 triple collocation (TC) statistics |
| url | http://www.mdpi.com/2072-4292/9/2/104 |
| work_keys_str_mv | AT xuefeizhang validationanalysisofsmapandamsr2soilmoistureproductsovertheunitedstatesusinggroundbasedmeasurements AT tingtingzhang validationanalysisofsmapandamsr2soilmoistureproductsovertheunitedstatesusinggroundbasedmeasurements AT pingzhou validationanalysisofsmapandamsr2soilmoistureproductsovertheunitedstatesusinggroundbasedmeasurements AT yunshao validationanalysisofsmapandamsr2soilmoistureproductsovertheunitedstatesusinggroundbasedmeasurements AT shangao validationanalysisofsmapandamsr2soilmoistureproductsovertheunitedstatesusinggroundbasedmeasurements |