The Surface Imaging System (SIS) records road pavement surface when travelling on a pavement at traffic speed. A light system is included. The line scan camera technology is used for continuous undistorted images. Surface Imaging Systems can operate as a separate system or be a subsystem to a Greenwood Profiler.
To obtain sharp images an array of high power flashing LEDís is used. For every 1mm the vehicle moves (depending on the resolution), the LED light makes a flash with a strength many times stronger than the sunlight, which removes shadows cast due to the sun. By using this technology the power consumption is proportional to the vehicle speed, and power can therefore be generated by the engine of the vehicle. Light Emitting Diodes (LED) lighting are used for low power consumption and high reliability. Multidirectional strobed illumination enhancing pavement damages and ease automatic analysis. The images can be synchronized with other measurement systems like GPS and profiles from the Profiler.
The resulting image is one long image in the total traveled distance. This eliminates the overlap algorithms that combines standard single frames. All images are stored in raw format with time and distance information of all pixels.