On-Orbit Performance Verification of the ICESat-2/ATLAS Onboard Receiver Algorithms

NASA's Advanced Topographic Laser Altimeter System (ATLAS) is the single instrument on the ICESat-2 spacecraft which launches in September 2018 with a 3 year mission lifetime. The ICESat-2 planned orbital altitude is 500 km with a 92 degree inclination and 91-day repeat tracks. ATLAS is a single-photon detection system transmitting at 532nm with a laser repetition rate of 10 kHz and a 6 spot pattern on the Earth's surface.

Without some method of reducing the received data, the volume of ATLAS telemetry would far exceed the normal X-band downlink capability. To reduce the data volume to an acceptable level a set of onboard Receiver Algorithms has been developed. These Algorithms limit the daily data volume by distinguishing surface echoes from the background noise and allowing the instrument to telemeter data from only a small vertical region about the surface location. This is accomplished through the use of an onboard Digital Elevation Model (DEM), signal processing techniques, and onboard relief and surface type reference maps.

The ATLAS Receiver Algorithms have been tested and verified to the extent possible during the ICESat-2 / ATLAS instrument ground testing. While the performance of the Receiver Algorithms will be monitored and assessed throughout the first year of on-orbit data collection, post launch commissioning during October and November involves extensive testing and calibration. This poster will present the results of this preliminary on-orbit performance assessment of the ATLAS Receiver Algorithms. See the companion poster (Carabajal, et al) in this session.