From The Sheet (Katie Vane):
The ASO is a repurposed de Havilland Twin Otter plane, equipped with LiDAR (a remote sensing method that uses light in the form of a pulsed laser to generate three-dimensional information on surface characteristics), spectrometer, GPS, and an inertial measurement unit that tracks the pitch and yaw of the aircraft.
Together, the LiDAR and spectrometer, which measure both topography and reflected sunlight, create a three-dimensional map of the snowpack.
Incredibly, LiDAR data gathered from 20,000 feet in the air can measure snowpack topography to within 10 centimeters, Painter said.
The purpose of this data is to represent snowpack, particularly its water equivalent, “in a more meaningful way.”
Until now, snowpack data was typically measured using snow courses or snow pillows. Both snow courses and pillows offer limited information, as neither one covers a large amount of terrain. “The greater purpose of them is as an indicator of percentage [of average],” Painter said. “But water isn’t allocated in percentages; it’s allocated in acre-feet.”
“Remote sensing is key to understanding the whole of the mountain snowpack,” he concluded.
Considering about 75 percent of the freshwater supply for the Western U.S. comes from snowmelt, understanding mountain snowpack and calculating the snow water equivalent with greater precision is crucial for more refined water management.
More Colorado River Basin coverage here.