Abstract:The orbits of altimetry satellites should be repeat groundtrack and frozen. We derive an algorithm of the orbit design based on zonal geopotential field and develop the software by ourselves. This paper takes ICESat and HY-2A as examples, computing their mean orbit elements and osculation orbit elements. The orbit generation results show that the satellites can get a nice closure after a full cycle and there is no secular and long period change for the semi-major, eccentricity, inclination and the argument of perigee. The orbit can meet the requirement of altimetry satellites and can be taken as a reference orbit.