This summarizes the laboratory experiments using current 5 RF sensors. During the second year, reliability testing of 5 RF sensors was conducted using 20 dB attenuators. Next, a second set of experiments was designed to simulate the snowpack under laboratory conditions. For this purpose, SWE was simulated as a depth of liquid water in Regicell Foam layers with different depths an different porosities. Results from this system level test were presented at the 2007 Fall Meeting of the American Geophysical Union in San Francisco, CA in December 2007.
Currently, we are working on developing the algorithm to extract amplitude change and phase shift as a function of time. The challenge is to quantity the phase shift accurately given that to keep the sensor costs down, the sensors to not have a reference clock. After quantifying the phase shift and amplitude, the complex permittivity of a variety of simulated “snowpacks” corresponding to varying liquid water depths, and foam thickness and porosity combinations will be characterized in the lab before going to actual field work with the snow sensor. I plan to perform field work in the upcoming 2008-2009 winter season in Finland via the GPM GV agreement and in the US.