Subcycle Analysis for ICESat's Repeat Groundtrack Orbits and Application to Phasing Maneuvers

The concept of repeat groundtrack orbit subcycles is presented in a general definition. The subcycles of ICESat's 91-day repeat groundtrack orbit and their track offsets are mapped out on a chart of subcycles, which are used to decompose the repeat cycle into three main subcycles. The influence of the synchronicity parameters of the repeat groundtrack orbit is discussed using the Bezout equation. In a second part, a fuel efficient maneuver, called phasing maneuver, which enables the repositioning of the ICESat satellite into a different part of its repeat cycle is presented. A correlation between the properties of the transition orbit used to accomplish this phasing and the properties of ICESat subcycles are described. Results from on-orbit experience are given.