A method and system for scanning and measuring an environment is provided. The method includes acquiring a first group of 3D coordinates of the area with a first 3D measurement device. The first 3D measurement device determines a distance to a surface in the area based at least in part on the speed of light. A second group of coordinates is acquired with a second measurement device while the first 3D measurement device is moved through the environment. The second measurement device being in a fixed relationship to the first 3D measurement device. The second measurement device determining a position of the second measurement device based on one or more points on the surface in the area based at least in part on a projected light. The first group of 3D coordinates is registered based at least in part the second group of coordinates.