We have two different products in our long distance measurement range of products. The range includes API laser trackers as well as the 3D Disto product from Leica Geosystems.
Laser trackers measure X,Y, Z coordinates of points in space and distances between points up to 80 metres away from the measuring instrument at incredibly high accuracy – less than 0.4 mm at this distance, using laser interferometers and time of flight systems.
The 3D Disto is a different instrument in that it is using laser beams to determine the distance from the instrument to a laser point on a surface or wall with millimetre accuracy over a 50 metre range.