Design and Development of a Simulation System for GNSS Radio Occultation Satellite Constellation Design

Abstract

Space-borne global navigation satellite system (GNSS) radio occultation (RO) is a superior tool for global sounding of atmosphere and ionosphere. The amount of operated low Earth orbit (LEO) satellite equipped with GNSS RO receivers for atmospheric sounding are surging in recent years. The orbits of these RO sounding satellites are varied because of the requirement of multitask. A digital simulation system aimed at GNSS RO atmospheric sounding satellite constellation design with or without on-orbit LEO satellites is presented in this paper. The system contains two main simulation modules. One of them is a transient position and velocity generator for both LEO satellites and GNSS satellites. The other is a forward GNSS RO event simulator for GNSS-LEO atmospheric sounding. In addition, a data processing module and graphical user interface (GUI) are designed and developed for interacting the data convenient and efficient in the initiative design of LEO satellite constellation. A Walker-δ satellite constellation with 6 LEO satellites is designed based on this system with simulations of GPS RO atmospheric sounding.