PROJECTILE DETECTION
FIG2 is a plan view of a sensor plate of a sensor of the illustrated embodiment
The acoustic sensor 20 is of known type, as described in European Patent Application EP2884762A1. The acoustic sensor 20 includes a circular sensor plate 40, as illustrated in FIG2. The sensor plate 40 has five through holes 42 defined therein. The through holes 42 are arranged in a cruciform formation, centred with the sensor plate 40. Each through-hole 42 has a microphone 44 mounted therein, oriented so as to be directed to detect sound emanating from the exterior of the acoustic sensor 20.
plan view
42
through holes
44
microphone microphones
40
sensor plate
['1. A method of detecting trajectory information for a subsonic projectile, comprising: collecting detection signals from an array of detection microphones, the detection microphones being established in a non co-linear spatial relationship with respect to each other; determining from at least one of the detection signals the existence of an acoustic waveform, a wake contribution, characteristic of the wake of a subsonic projectile passing on a trajectory nearby; obtaining a plurality of time samples of the wake contribution over a time period; processing the plurality of time samples to determine geometric characteristics of the trajectory of the projectile.']