ICESat-2 By the Numbers

300 trillones.Música: Fred Dubois, Killer TracksTranscripción completa disponible.Watch this video on the NASA Goddard YouTube channel.

ICESat-2 orbiting Earth: starting with global view building up ground track, then riding the satellite view, then back to a global view with full ground track || ICESat-2 is a spacecraft designed to accurately measure land and ice elevations on Earth. By comparing observations from different times, scientists will be able to study changes in elevations. ICESat-2 will be in a polar orbit which will provide high coverage near the poles where ice elevations are changing relatively quickly. This visualization shows ICESat-2 s global coverage which repeats about once every 90 days.The ATLAS lidar on ICESat-2 uses 3 pairs of laser beams to measure the earth’s elevation and elevation change. As a global mission, ICESat-2 will collect data over the entire globe, however the ATLAS instrument is optimized to measure land ice and sea ice elevation in the polar regions.For more information on ICESat-2 click here. || ICESat-2 orbit with ground track (short version)

ICESat-2 has 3 pairs of lasers that will measure the heights of ice and snow at very high resolution || The ATLAS lidar on ICESat-2 uses 6 laser beams to measure the earth’s elevation and elevation change. As a global mission, ICESat-2 will collect data over the entire globe, however the ATLAS instrument is optimized to measure land ice and sea ice elevation in the polar regions. ICESat-2 reports elevations with respect to a reference surface, called an ellipsoid. In this measurement system, shared by GPS devices, an elevation of zero meters indicates the notional sea level, although tides, wind, and waves can make the actual sea level either greater than or less than zero. The Antarctic ice sheet, shown here, ranges up to 4000m above sea level. Over the course of 91 days, ATLAS will generate 1387 ground tracks across Antarctica for each of it’s 6 beams.

Side view of the beam pairs. || The ATLAS lidar on ICESat-2 uses 6 laser beams to measure the earth’s elevation and elevation change. By arranging the beams in three pairs of two, scientists can also determine the slope between the two beams, a key component of determining elevation change along the Reference Ground Track. Each time ATLAS collects data along a particular track, onboard software aims the laser beams so that the Reference Ground Track is always between the two beams, as shown in the animation. This allows scientists to combine the elevation and slope information from two different passes to determine elevation change along the Reference Ground Track. || Top-down view of the beam pairs.

Animation showing the deployment of the spacecraft and a beauty pass with the beams on. || The Ice, Cloud and land Elevation Satellite-2, or ICESat-2, is a laser altimeter that will measure the heights of Earth’s surfaces. With ICESat-2’s high-resolution data, scientists will track changes to Earth’s ice-covered poles, which is witnessing dramatic temperature increases. The mission will also take stock of forests, map ocean surfaces, characterize clouds and more.ICESat-2 carries a single instrument called the Advanced Topographic Laser Altimeter System (ATLAS), equipped with a multiple-beam laser, which sends 10,000 pulses of light to the ground each second. A small fraction of the light photons bounce off Earth’s surface and return to the instrument, where a photon-counting detector times their flight. Knowing this time, and the satellite’s position and orientation in space, scientists can calculate Earth’s elevation below.ICESat-2 continues key elevation observations begun by the original ICESat satellite (2003 to 2009) and Operation IceBridge (2009 through present), to provide a portrait of change in the beginning of the 21st century. || High resolution print graphic of the spacecraft above the Earth.