Examining the scale dependence of the statistical relationship between snow depth and microwave radiance (Invited)
Abstract
Interpretation and characterization of hydrologic processes and states via passive microwave (PM) remote sensing measurements of snow cover are impeded by the discrepancy in scale between remote sensing and in situ measurements. In situ measurements differ from remote sensing measurements in that the former measure only selected locations within the spatial footprint of the latter. However, the extent to which the coarse PM resolution results in loss of information about the average snow properties within the footprint is not well understood. This paper addresses the question: How does information about snow properties vary as a function of the scale of PM measurements? To that end, we address a proxy question: How does the statistical relationship between in situ and remote sensing measurements vary as a function of scale? We utilize the multi-scale CLPX 2002 - 2003 dataset. The NASA CLPX was a multi-sensor, multi-scale field campaign designed to extend knowledge of local-scale processes to regional and global scales. Airborne passive microwave data were collected using the Multiband Polarimetric Scanning Radiometer (PSR). Intensive ground measurements of snow properties were performed within the ISAs. Generally, these ground measurements consisted of snow depth transects and snow pit measurements. We compare the CLPX in situ measurements with microwave brightness temperatures at a variety of scales spanning 100 meters to tens of kilometers. We make comparisons by constructing multivariate statistical relationships between snow measurements and remote sensing measurements. Our goal is to quantify how much information about snow properties remote sensing measurements contain as a function of scale. We use the strength of the statistical relationship between the PM measurements and the SWE as a proxy for the information about SWE contained in the PM measurements. We construct multivariate statistical relationships between in situ and PM measurements at a variety of scales, and examine how the regression coefficients, correlation coefficients, etc. change as a function of the scale of the PM measurement.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.C22A..01D
- Keywords:
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- 0736 CRYOSPHERE / Snow;
- 0758 CRYOSPHERE / Remote sensing