The Effects of Dry Snow on the SAR Impulse Response and Feasibility for Single Channel Snow Water Equivalent Estimation
- 12 July 2021
- journal article
- research article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Geoscience and Remote Sensing
- Vol. 60 (01962892), 1-23
- https://doi.org/10.1109/tgrs.2021.3089131
Abstract
Snow water equivalent (SWE) is an important surface parameter for understanding a number of Earth system processes. Synthetic aperture radar (SAR) has considerable potential for measuring SWE of dry-snow because SAR can penetrate through the snow to the ground surface and is both amplitude- and phase-sensitive to refraction from the snow. Previous work on refraction-based SWE measurement by SAR has utilized the repeat-pass InSAR phase signal to estimate changes in SWE that occur between SAR acquisitions. These are subject to temporal decorrelation effects and consider only the refraction that occurs along the SAR beam center rather than the entire synthetic aperture. This study examines the refractive effect of dry-snow along the synthetic aperture and its impact on SAR image formation including defocusing and phase bias of the system impulse response. Snow phase compensation during time domain processing to recover the snow-free impulse response function (IRF) is described and demonstrated. The feasibility of using the mapdrift and image sharpness autofocus methods to estimate SWE is examined, and the effect of key system parameters on the estimation performance is derived. Experimental validation of the method was conducted by acquiring L-band data with the Simon Fraser University (SFU) Airborne SAR System over a pair of corner reflectors installed on the Kluane icefield in northwestern Canada. Results from both simulations and the icefield experiment are presented and compared including an analysis of errors affecting the estimation.Keywords
This publication has 50 references indexed in Scilit:
- Vertical measurement accuracy and reliability of mapping-grade GPS receiversComputers and Electronics in Agriculture, 2011
- Estimating Snow Water Equivalent Using Snow Depth Data and Climate ClassesJournal of Hydrometeorology, 2010
- Towards automated ‘Ground truth’ snow measurements—a review of operational and new measurement methods for Sweden, Norway, and FinlandHydrological Processes, 2010
- Snowpack properties for snow profile analysisCold Regions Science and Technology, 2003
- The influence of thermal, hydrologic, and snow deformation mechanisms on snow water equivalent pressure sensor accuracyHydrological Processes, 2002
- Mapping wet snowcovers with SAR interferometryInternational Journal of Remote Sensing, 1999
- Subaperture autofocus for synthetic aperture radarIEEE Transactions on Aerospace and Electronic Systems, 1994
- Applications of the interaction of microwaves with the natural snow coverRemote Sensing Reviews, 1987
- Refractive index of snow at microwave frequenciesApplied Optics, 1985
- Snow Surveying: Its Principles and PossibilitiesGeographical Review, 1933