sentences:  The LIDAR memory could save up to six return detections per laser firing, with a threshold set for the best compromise between missed detections and false alarms.The returns were stored in 39.972 m range bins, equal to the resolution of the 14-bit clock counter.The LIDAR has a nominal range of 500 km, but altimetric data was gathered for altitudes up to 640 km, which allowed coverage from 60 degrees south to 60 degrees north by the end of the lunar phase of the mission.