GOALI: Accurate, High Resolution Ladar for 3D Metrology at Large Standoff Distances

Montana State University, Bozeman MT

Investigators

Abstract

The research objective of this Grant Opportunity for Academic Liaison with Industry (GOALI) project is to apply frequency modulated continuous wave laser radar, also known as ladar, to high resolution, non-contact, large-volume, three-dimensional metrology. Non-contact methods of optical three-dimensional metrology are limited at longer ranges due to optical diffraction from finite sized receiver optics. Tunable laser sources, however, can now provide sufficient optical bandwidth to achieve ranging resolution of sub 50 microns with measurement precisions to diffuse targets of less than an optical wavelength in short integration times at tens of meter distances. The approach of this project is use the ultra-high range resolution provided by tunable laser sources, and apply trilateration and synthetic aperture imaging techniques to leverage this resolution for measurements transverse to the optical propagation. The project will investigate the formation and accurate registration of ultra-high resolution three-dimensional synthetic aperture images from multiple moving and stationary apertures. For metrology applications the tuning rate of the laser source must be stable and accurately calibrated. Therefore, a sub-objective will research the fundamental and practical limits to calibrating the measurement system. If successful, the benefits of the research project will include demonstration of a novel new method for accurate, large-scale, non-contact, industrial metrology. This method could benefit industries such as aerospace and energy that manufacture very large precision machinery, improving the speed and cost of manufacturing and improve machine life through tighter tolerances. This will help strengthen the United States' manufacturing base and benefit the national economy. This project will also help educate and train students in optics and engineering at Montana State University-Spectrum Lab a unique university research environment that includes close collaboration with the local optics industry in largely rural Montana, which is an EPSCoR member state.