3D mapping technique has functions in forensics and precision machining

According to NIST, the method may be useful in diverse fields including precision machining and assembly, plus forensics.

NIST’s 3D mapping system is said to combine a form of laser detection and ranging (LADAR), which is sensitive enough to detect weak reflected light, with the ranging accuracy made possible by frequency combs. The frequency comb, a tool for precisely measuring different frequencies of light, is used to continuously calibrate the laser in the imaging system.

Operating with laser power of nine milliwatts, NIST’s 3D mapping system scans a target object point by point across a grid, measuring the distance to each point. The system uses the distance data to make a 3D image of about one million pixels in under 8.5 minutes at the current scanning rate. Distances to points on a rough surface that reflects light in many directions can be determined to within 10 micrometres in half a millisecond, with an accuracy that is traceable to a frequency standard.