학술논문
Comparison of downscaling techniques for high resolution soil moisture mapping
Document Type
Conference
Author
Sabaghy, Sabah; Walker, Jeffrey; Renzullo, Luigi; Akbar, Ruzbeh; Chan, Steven; Chaubell, Julian; Das, Narendra; Dunbar, R. Scott; Entekhabi, Dara; Gevaert, Anouk; Jackson, Thomas; Merlin, Olivier; Moghaddam, Mahta; Peng, Jinzheng; Piepmeier, Jeffrey; Piles, Maria; Portal, Gerard; Rudiger, Christoph; Stefan, Vivien; Wu, Xiaoling; Ye, Nan; Yueh, Simon
Source
2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS) Geoscience and Remote Sensing Symposium (IGARSS), 2017 IEEE International. :2523-2526 Jul, 2017
Subject
Language
ISSN
2153-7003
Abstract
Soil moisture impacts exchanges of water, energy and carbon fluxes between the land surface and the atmosphere. Passive microwave remote sensing at L-band can capture spatial and temporal patterns of soil moisture in the landscape. Both ESA and NASA have launched L-band radiometers, in the form of the SMOS and SMAP satellites respectively, to monitor soil moisture globally, every 3-day at about 40 km resolution. However, their coarse scale restricts the range of applications. While SMAP included an L-band radar to downscale the radiometer soil moisture to 9 km, the radar failed after 3 months and this initial approach is not applicable to developing a consistent long term soil moisture product across the two missions anymore. Existing optical-, radiometer-, and oversampling-based downscaling methods could be an alternative to the radar-based approach for delivering such data. Nevertheless, retrieval of a consistent high resolution soil moisture product remains a challenge, and there has been no comprehensive intercomparison of the alternate approaches. This research undertakes an assessment of the different downscaling approaches using the SMAPEx-4 field campaign data.