APPENDIX 1
The high-speed photographic camera used at by R.F. Kinsler at the Army Research Laboratory is frequently operated with a repetition rate of 25 microseconds, a pulse duration of 1 microsecond, and a recording array of 304 by 192 pixels. This would yield a spatial resolution at a moving deformation front of 0.26 mm.1 For a BFD displacement rate of 100 m/s, the surface will move by only 0.1 mm during the 1 microsecond that the “shutter” is open, producing a small smear of the 0.26 mm spatial resolution.
A BFD of 40 mm would occur over approximately 1 millisecond. A repetition rate of 25 microseconds would therefore enable about 40 discrete contours of deformation to be recorded during a given shot with a spatial resolution of 0.26 mm and a velocity resolution of about 1 m/s.