TY - JOUR
T1 - Evaluation and inter-comparison of satellite soil moisture products using in situ observations over Texas, U.S.
AU - Ray, Ram L.
AU - Fares, Ali
AU - He, Yiping
AU - Temimi, Marouane
N1 - Publisher Copyright:
© 2017 by the authors.
PY - 2017/5/25
Y1 - 2017/5/25
N2 - The main goal of this study was to evaluate four major remote sensing soil moisture (SM) products over the state of Texas. These remote sensing products are: (i) the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) (2002-September 2011); (ii) the Soil Moisture Ocean Salinity system (SMOS, 2010-present); (iii) AMSR2 (2012-present); and (iv) the Soil Moisture Active Passive system (SMAP, 2015-present). The quality of the generated SM data is influenced by the accuracy and precision of the sensors and the retrieval algorithms used in processing raw data. Therefore, it is important to evaluate the quality of these satellite SM products using in situ measurements and/or by inter-comparing their data during overlapping periods. In this study, these two approaches were used where we compared each satellite SM product to in situ soil moisture measurements and we also conducted an inter-comparison of the four satellite SM products at 15 different locations in Texas over six major land cover types (cropland, shrub, grassland, forest, pasture and developed) and eight climate zones along with in situ SM data from 15 Mesonet, USCRN and USDA-NRCS Scan stations. Results show that SM data from SMAP had the best correlation coefficients range from 0.37 to 0.92 with in situ measurements among the four tested satellite surface SM products. On the other hand, SM data from SMOS, AMSR2 and AMSR-E had moderate to low correlation coefficients ranges with in situ data, respectively, from 0.24-0.78, 0.07-0.62 and 0.05-0.52. During the overlapping periods, average root mean square errors (RMSEs) of the correlations between in situ and each satellite data were 0.13 (AMSR-E) and 0.13 (SMOS) cm3/cm3 (2010-2011), 0.16 (AMSR2) and 0.14 (SMOS) cm3/cm3 (2012-2016) and 0.13, 0.16, 0.14 (SMAP, AMSR2, SMOS) cm3/cm3 (2015-2016), respectively. Despite the coarser spatial resolution of all four satellite products (25-36 km), their SM measurements are considered reasonable and can be effectively used for different applications, e.g., flood forecasting, and drought prediction; however, further evaluation of each satellite product is recommended prior to its use in practical applications.
AB - The main goal of this study was to evaluate four major remote sensing soil moisture (SM) products over the state of Texas. These remote sensing products are: (i) the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) (2002-September 2011); (ii) the Soil Moisture Ocean Salinity system (SMOS, 2010-present); (iii) AMSR2 (2012-present); and (iv) the Soil Moisture Active Passive system (SMAP, 2015-present). The quality of the generated SM data is influenced by the accuracy and precision of the sensors and the retrieval algorithms used in processing raw data. Therefore, it is important to evaluate the quality of these satellite SM products using in situ measurements and/or by inter-comparing their data during overlapping periods. In this study, these two approaches were used where we compared each satellite SM product to in situ soil moisture measurements and we also conducted an inter-comparison of the four satellite SM products at 15 different locations in Texas over six major land cover types (cropland, shrub, grassland, forest, pasture and developed) and eight climate zones along with in situ SM data from 15 Mesonet, USCRN and USDA-NRCS Scan stations. Results show that SM data from SMAP had the best correlation coefficients range from 0.37 to 0.92 with in situ measurements among the four tested satellite surface SM products. On the other hand, SM data from SMOS, AMSR2 and AMSR-E had moderate to low correlation coefficients ranges with in situ data, respectively, from 0.24-0.78, 0.07-0.62 and 0.05-0.52. During the overlapping periods, average root mean square errors (RMSEs) of the correlations between in situ and each satellite data were 0.13 (AMSR-E) and 0.13 (SMOS) cm3/cm3 (2010-2011), 0.16 (AMSR2) and 0.14 (SMOS) cm3/cm3 (2012-2016) and 0.13, 0.16, 0.14 (SMAP, AMSR2, SMOS) cm3/cm3 (2015-2016), respectively. Despite the coarser spatial resolution of all four satellite products (25-36 km), their SM measurements are considered reasonable and can be effectively used for different applications, e.g., flood forecasting, and drought prediction; however, further evaluation of each satellite product is recommended prior to its use in practical applications.
KW - AMSR-E
KW - AMSR2
KW - Agriculture
KW - Hydrology
KW - Meteorology
KW - SMAP
KW - SMOS
KW - Soil moisture
UR - http://www.scopus.com/inward/record.url?scp=85020402967&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020402967&partnerID=8YFLogxK
U2 - 10.3390/w9060372
DO - 10.3390/w9060372
M3 - Article
AN - SCOPUS:85020402967
VL - 9
JO - Water (Switzerland)
JF - Water (Switzerland)
IS - 6
M1 - 372
ER -