New technology from NASA'S MABEL program will allow researchers to track the melt or growth of icy regions on Earth.
The laser-based technology counts photons, allowing researchers to observe changes in ice cover, a NASA news release reported.
MABEL and ICESat-2's ATLAS instrument send out pulses of green laser light and count how long it takes each pulse to bounce off Earth's surface and return to the device.
"Using the individual photons to measure surface elevation is a really new thing," Ron Kwok, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif, said in a news release. "It's never been done from orbiting satellites, and it hasn't really been done much with airborne instruments, either."
ICESat-2 measures the "elevation across Earth's entire surface" such as oceans and vegetation but focuses on icy regions. MABEL delivers individual photon data.
"We wanted to get a wide variety of target types, so that the science team would have a lot of data to develop algorithms," Bill Cook, MABEL's lead scientist at NASA's Goddard Space Flight Center. "This was our first real dedicated science mission."
The MABEL mission first mapped out Greenland in 2012; the team used this initial test to determine what methods worked best to interpret the data.
"Part of what we're doing with MABEL is to demonstrate ICESat-2's instrument is going to have the right sensitivity to do the measurements," Cook said. "You can do this photon counting if you have enough photons."
ICESat-1 only used one laser, often making it difficult to measure elevation. In one case an area required 10 flybys to confirm its elevation.
"ICESat-1 was fantastic, but it was a single beam instrument," Kelly Brunt, a research scientist at NASA Goddard said in the news release. "We're more interested in repeating tracks to monitor change - that's hard to do."
ICESat-2 split the laser into six beams which proved to be much more efficient.
"The precision is great," Brunt said. "We're very confident that with ICESat-2's beam pair, we can see slope."
