Investigating a Radio Data Link to a Railgun Projectile—The Active Projectile

In railguns, projectiles can be accelerated to velocities of up to several kilometers per second. In many respects, a railgun represents a harsh environment for the projectile. To obtain large muzzle velocities, it has to withstand extreme acceleration, friction, and heat. The large currents being involved give rise to strong magnetic fields and field gradients. All these effects might affect any electronic circuitry that the projectile is being equipped with. To be able to monitor parameters like current, magnetic field strength, temperature, instantaneous acceleration, etc., by sensors being mounted on the projectile would be beneficial for the understanding of the extreme conditions being associated with the acceleration process. This investigation uses commercial 433-MHz transmission systems to establish a one-way link from the projectile to the laboratory. Results from proof-of-principle experiments are reported.