Roll Angle Estimation of Smart Projectiles using GNSS Signal

An accurate roll angle measurement is essential for guidance of smart projectiles. Due to the extreme operational requirements, the conventional gyros are not able to provide roll angle estimation in the absence of initial values post launch phase due to sensor saturation. This paper describes two alternate methods for roll angle estimation using Global Navigation Satellite System (GNSS). A flight dynamics model and GNSS measurements based on open source simulation software are used to provide a comparative analysis of two methods based on using single and double antennas. A projectile simulation estimates the position, velocity and attitude of a projectile when it is launched with the given launch conditions. Similarly, the satellite simulation estimates the position and orbit of satellites provided the orbital parameters. These simulations are used in validation of these alternate methods. The simulation results show that single antenna method is more accurate than the double antenna method, however a choice has to be made based on the operational requirements.