Comprehensive analysis of alternative downscaled soil moisture products

REMOTE SENSING OF ENVIRONMENT

卷:239

Article

Sabaghy, Sabah¹  Walker, Jeffrey P.¹  Renzullo, Luigi J.²  Akbar, Ruzbeh⁵  Chan, Steven³  Chaubell, Julian³  Das, Narendra³  Dunbar, R. Scott³  Entekhabi, Dara⁵  Gevaert, Anouk⁴  Jackson, Thomas J.⁶  Loew, Alexander¹¹  Merlin, Olivier⁷  Moghaddam, Mahta⁸  Peng, Jian^11,12,13  Peng, Jinzheng^9,10  Piepmeier, Jeffrey⁹  Rudiger, Christoph¹  Stefan, Vivien⁷  Wu, Xiaoling¹  Ye, Nan¹  Yueh, Simon³ 

[1] Monash Univ, Dept Civil Engn, Clayton, Vic 3800, Australia

[2] Australian Natl Univ, Fenner Sch Environm & Soc, Canberra, ACT, Australia

[3] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA

[4] Vrije Univ Amsterdam, Dept Earth Sci, Earth & Climate Cluster, Amsterdam, Netherlands

[5] MIT, Dept Civil & Environm Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA

[6] ARS, USDA, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA

[7] Ctr Etud Spatiales Biosphere CESBIO, 18 Ave,Bpi 2801, F-31401 Toulouse, France

[8] Univ Southern Calif, Dept Elect Engn, Los Angeles, CA 90089 USA

[9] Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA

[10] Univ Space Res Assoc, Columbia, MD USA

[11] Univ Munich LMU, Dept Geog, D-80333 Munich, Germany

[12] Univ Oxford, Sch Geog & Environm, Oxford OX1 3QY, England

[13] Max Planck Inst Meteorol, D-20146 Hamburg, Germany

关键词: Downscaling;    Disaggregation;    Inter-comparison;    High resolution;    Soil moisture;    SMAP;    SMOS;    SMAPEx;   

DOI  :  10.1016/j.rse.2019.111586

来源: Elsevier

【 摘 要 】

Recent advances in L-band passive microwave remote sensing provide an unprecedented opportunity to monitor soil moisture at similar to 40 km spatial resolution around the globe. Nevertheless, retrieval of the accurate high spatial resolution soil moisture maps that are required to satisfy hydro-meteorological and agricultural applications remains a challenge. Currently, a variety of downscaling, otherwise known as disaggregation techniques have been proposed as the solution to disaggregate the coarse passive microwave soil moisture into high-to-medium resolutions. These techniques take advantage of the strengths of both the passive microwave observations of soil moisture having low spatial resolution and the spatially detailed information on land surface features that either influence or represent soil moisture variability. However, such techniques have typically been developed and tested individually under differing weather and climate conditions, meaning that there is no clear guidance on which technique performs the best. Consequently, this paper presents a quantitative assessment of the existing radar-, optical-, radiometer-, and oversampling-based downscaling techniques using a singular extensive data set collected specifically for that purpose, being the Soil Moisture Active Passive Experiment (SMAPEx)-4 and -5 airborne field campaigns, and the OzNet in situ stations, to determine the relative strengths and weaknesses of their performances. The oversampling-based soil moisture product best captured the temporal and spatial variability of the reference soil moisture overall, though the radar-based products had a better temporal agreement with airborne soil moisture during the short SMAPEx-4 period. Moreover, the difference between temporal analysis of products against in situ and airborne soil moisture reference data sets pointed to the fact that relying on in situ measurements alone is not appropriate for validation of spatially enhanced soil moisture maps.

【 授权许可】

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