Using PROPAC also time varying surface motions can be measured, since the measurement signal from the complete surface is captured at once by the CCD camera at a specific instance of time. Image blur can be eliminated by reducing the camera shutter-time or by using a pulsed light source for the projection of the patterns. Pulse lasers can be used to achieve pulse durations of only a few nanoseconds. High-Speed cameras and lasers recording rates of some kHz can be used to enable time-resolved deformation measurements of short duration. A typical application of PROPAC for periodic movements is the modal analysis of complex vibrating structures.
This example shows that PROPAC can be applied also to larger surface areas as that of aircraft wings and flaps for example. The advantages of PROPAC are short set-up times and a fast data acquisition, whereas no modifications of the structure and its surfaces are necessary. Using a CCD camera with increased number of pixels the achievable measurement precision can be improved accordingly for a specific size of measurement area. The application of PROPAC is also suitable for smaller measurement areas to get quickly quantitative information of the vibration of complex parts, especially if larger amplitudes occur, e.g. circuit boards with electrical components.