ICESat-2 ATLAS PMT after-pulsing effects

The Advanced Topographic Laser Altimeter System (ATLAS) instrument aboard the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) has made measurements since October 2018. The ATLAS uses photomultiplier Tubes (PMTs) as detectors in photon counting mode where single photon reflected from the surface triggers a detection within the ICESat-2 receiver. However, one characteristic of PMT is after-pulses, which are pulses with small amplitudes appearing after the primary signal pulse. The disadvantage of PMT after-pulses is that they often disturb accurate measurements of low level signals following a large amplitude of signal, degrade energy resolution, and causes errors in pulse counting applications. This paper discusses and summarizes the ICESat-2 ATLAS PMTs after-pulsing effects from the on-orbit measurements over different regions with different surface types. The impact of the ICESat-2 detector's artifact on altimetry and ocean subsurface retrievals is discussed.