Optical
velocity-measurement techniques for supersonic surfaces
Interferometric
techniques have been used routinely for more than 20 years to measure
velocities of explosive shock-fronts. Recently, structured-light measurements
have been used for the same purpose. Explosions accelerate surfaces to as much
as 15 km/sec in a nanosecond or less, often generating much light, large
changes in reflectivity, and ejecting particles or layers at different speeds.
I will describe the current performance of fiber-optic
displacement-interferometers, Fabret-Perot inteferometers, velocity
interferometers (VISAR), and structured light, in this interesting physical
space.