The Laser Range Finder
*Measures distance from GPS unit to object to be mapped. *Digital compass measures the direction. *Digital level measures the angle. *Software automatically adjusts GPS reading to account for this offset.
The GPS unit gives us the location where the GPS unit is.   That is not always the location that we really want.
 Often it is inconvenient or not good GPS practice to stand next to the object being mapped.
So, we get the location information of where we are standing and use the LASER RANGE FINDER TO:
(1)Measure the distance to what we want to map
(2)Measure the compass direction of what we want to map
(3)Measure the change in altitude of what we want to map.
Once we have this,the GPS software automatically adjusts the  GPS reading.