Initial Results in Developing Free Flight Testing Techniques for Artillery Shells

As part of a programme to develop methods for studying the exterior ballistics of shells, an initial series of four shells was fired at Woomera. Two shells carried yawsondes designed and manufactured at the Ballistic Research Laboratories in the United States of America and two carried preliminary designs of a locally developed yawsonde. Trajectory of the shells was obtained from radar tracking. Both the trajectory and the yawsonde data were analysed using parameter estimation algorithms and the results of the data analysis are reported here. Roll damping, axial force and normal force derivatives were determined for subsonic speeds up to Mach 0.8. Conclusions on the efficacy of the trials technique have been reached and these lead to recommendations for future trials. (Author)