Instrumentation of the basic finner reference projectile for attitude measurements at supersonic velocities

Attitude measurements of reference projectiles are required in order to validate numerical aerodynamic simulations as well as dedicated numerical tools for the aerodynamic coefficient determination, based on a 6 degrees of freedom (DoF) data reduction. In this context we recently performed firing campaigns with a well-known reference projectile called “basic finner” (BF) [1], [2]. In comparison to the previous work [1], [2] in which shadow graphs were taken in firing tunnels, the BF is now instrumented with onboard attitude sensors and free-flight data is transmitted in real time to a receiving station. Telemetry for projectiles has been an issue for a long time [3], and progress has been made continuously throughout the years, with wider bandwidth and higher frequencies [4]–[14] in specialized centers of many countries (mainly, but not exclusively by the Army Research Laboratory (ARL) in the USA, and the French-German Research Institute of Saint- Louis (ISL) in France). D-fuze [10] is a patented measurement system integrating attitude sensors, acquisition electronics, and transmitter in a fuze (NATO-compatible shape), for large caliber projectiles and firing ranges; many U.S. development programs benefited from this advance in technology during the last decade. In [11], a miniaturized electronic of diameter 18 mm was used onboard a kinetic projectile in combination with specific equipment dedicated to telemetry reception.