Colorado scientists put stray satellite signals to work measuring snow - key data in arid West

DENVER – Climate scientists are gleaning valuable information about snowfall and droughts from errant satellite signals once considered a nuisance.

The data comes from GPS receivers that earthquake scientists use to detect motion in the Earth’s surface.

The receivers use signals from GPS satellites to measure movement. But there’s a problem: In addition to picking up signals directly from the satellites, the receivers also pick up satellite signals that bounce off the ground first, providing false readings.

Colorado scientists discovered they can use those nuisance signals to measure snow depth and soil moisture around the receivers.

That’s valuable information in the arid West, where snow depth in the mountains determines how much water will be available to cities and farms when runoff starts in the spring.