Simulation of GPS-based Launch Vehicle
Trajectory Estimation using UNSW Kea
GPS Receiver
Sanat Biswas
Australian Centre for Space Engineering Research,
UNSW Australia, s.biswas@unsw.edu.au
Li Qiao
School of Engineering and Information Technology,
UNSW Australia, L.qiao@adfa.edu.au
Andrew Dempster
Australian Centre for Space Engineering Research,
UNSW Australia, a.dempster@unsw.edu.au
Abstract
The simulation procedure for GNSS-based position estimation of a launch
vehicle in a gravity turn trajectory is presented. A detailed mathematical
model of the dynamics of a multi-stage launch vehicle is developed. In the
mathematical model, the aerodynamic drag force and the jerk produced dur-
ing the stage separation are considered, specifically for the SpaceX Falcon 9
V1.1 launch vehicle in the Commercial Resupply Service (CRS)-5 mission.
The trajectory of the launch vehicle is simulated by using the vehicle and
mission-specific parameters in the developed model. The SPIRENT GNSS
simulator is used to generate the received GPS signals for the launch vehicle
trajectory. The signals are acquired by the UNSW Kea GPS receiver which is
optimized for acquiring GPS signals under high dynamics. The pseudo-range
measurements received by the Kea receiver are used to test the performance
of various estimation algorithms. This simulation procedure is convenient and
efficient for testing new GNSS receivers and new navigation algorithms for
launch vehicle applications.
1 Introduction
In recent years, innovative mission designs have enabled numerous possibilities of reduc-
ing the cost of accessing the space. For example, SpaceX has designed a reusable first
1
