By Sid Perkins
Measurements of satellite signals bouncing off a calm mountain lake may pave the way for a fleet of spaceborne sensors or groups of seaside towers that can quickly and inexpensively monitor local or global changes in sea level.
Central Oregon’s scenic Crater Lake, one of America’s deepest bodies of water, sits within the caldera left behind by an ancient volcanic eruption. From an observation point on the edge of the ancient crater and 480 meters above the lake, scientists recorded the signals coming straight from Earth-orbiting Global Positioning System (GPS) satellites, as well as the signals bouncing off the water’s surface.