PRISM Updates: Three frequencies of radar allow more accurate analysis...

Speaker: John Paden, graduate student, EECS, University of Kansas, 2002.

Modified Transcript: Our radar is operating at three different frequencies, whereas most radars operate at one frequency. The reason we are operating at three different frequencies is because we want to know both the reflectivity at the bottom of the ice and what the basal conditions are. We are interested in whether the bedrock is wet or dry under the ice. If it is wet then we want to be able to tell how thick the water layer is. That is what we mean by basal conditions. There are a lot of unknowns that come about because this hasn't been done before. If we use only one frequency to take measurements, then we might have to guess what caused a really bright signal. For example, it might be a peak of a mountain which causes a high reflectance or it might be a water interface there causing a high reflectance back. We plan to use three different frequencies to allow us to eliminate enough of the unknowns to get a clearer understanding of the signal. In other words, if we have three unknowns and three different measurements we can find out what all of the unknowns are.