A Methodology for Short Basis Velocity Measurement in Moving Objects

The velocity of various objects is currently measured within a large number of disciplines and activities. This paper presents velocity measurement in single-shot nonlinear processes, which occur only once and are thus characterized by zero repeatability. The measurement methods must therefore enable the recording, saving, and retroactive evaluation of the processes at a pre-defined accuracy; all these operations are performed to facilitate comparison of the recorded event and other similar processes. The methods commonly applied in the measurement of object velocity are based on optical and electromagnetic effects. In this context, the main disadvantage of optoelectronic methods consists in that the detector cannot be placed immediately behind the plasma source (or, generally, objects other than the projectile). Further problematic aspects can be identified in the emitted raw powder particles, muzzle flash, and shock wave, namely spurious effects leaving a track where the information from the launched projectile could be lost. However, the electromagnetic method described in the paper does not possess the disadvantages of the optical methods. We therefore present a design of an induction sensor fitted with an electronic signal processing system; this design is based on numerical evaluation of the relativistic effect occurring in the application of the electromagnetic principle of position sensing/object velocity [1]. The final part of the paper contains a discussion of the measured results.