Remote Sensing using Coherent Multipath Interference of Wideband Planck Radiation

A novel microwave radiometric technique, known as wideband autocorrelation radiometry (WiBAR), is introduced as a direct method to remotely measure the layer thickness of low-loss terrain covers such as snow and ice. This is done by measuring the propagation time tau(delay) from the autocorrelation function (ACF) of multipath microwave emission. We report measurements of the snowpack thickness using WiBAR at the University of Michigan Biological Station (UMBS) in winter 2015. The observations are done at frequencies from 1 to 3 GHz. At these frequencies, the volume and surface scattering are small in the snowpacks. This technique is inherently low-power since there is no transmitter as opposed to active remote sensing techniques.