Researchers at the University of Colorado have teased from what most engineers think of as unwanted "noise" received by antennas of the Global Positioning System a signal that allows them to measure the depth of snow and the level of moisture in soil and vegetation.
A recent study published in Geophysical Research Letters, a journal of the American Geophysical Union, confirms the ability of their method to measure snow depth that is "in good agreement" with on-site readings after two snowstorms last spring at a particular winter weather research site near Boulder, CO.
The method combines signals received by the antenna directly from a GPS satellite with other, noisy "multipath signals" that reach the antenna after bouncing off the ground.
(Click on the image and watch a University of Colorado video of the researchers explaining how they accomplished the feat.)
Leader of the study, CU-Boulder Professor Kristine Larson, an aerospace engineering sciences specialist who helped pioneer the use of GPS to measure tectonic movements, said the team hopes to apply the technique to data collected from an existing network known as the Plate Boundary Observatory of more than 1,000 GPS receivers arrayed around the West.
"By using the Plate Boundary Observatory for double duty, so to speak, we hope this will be a relatively inexpensive and accurate method that can benefit climate modelers, atmospheric researchers and farmers throughout the West," said Larson.