Figure 15:  a)To calibrate 3D LIDAR scans, on Tuesday January, 20, 2004, a Naik Prasad GPS team set datum control points to 1/100th ft. Accuracy;  b), Close-up of one of two GPS receivers  and field computers receiving coordinates from satellite signals.  Temperature at 14-17 degrees F.; c&d) LIDAR team scans historic Furnace Falls channel from first scan position on roof of Singer Building Wednesday, January 21, 2004 in 3D color at 12,000 , 6 mm, xyz coordinate points per second (Temperature at 17-27 degrees F.).