Poplar Point 1m LiDAR Grid

LiDAR Acquisition

LiDAR acquisition for this project was performed by Fugro Horizons  in a Twin Cessna 310 equipped with a Flimap Fx LiDAR system including an inertial measuring unit (IMU) and a dual frequency GPS receiver.  Acquisition was accomplished between October 2nd 2012 and October 11th 2012. The LiDAR flight specifications follow:
Field of View: 60 Degrees
Altitude:2100 feet AMT
Scan Rate:50 rps 
Pulse Rate:200 kHz
Airspeed:130 knots
Average Post Spacing: 4pts/m^2 
Average Swath Width: 650 Meters
Total Flight Lines: 47
Number of Lifts: 4

GPS Data Collection

A GPS receiver was in constant operation over a control point during flight acquisition.  The base station identification and location are listed in the following table. 
Base S1:49 48 46.10892, 97 58 57.04743, 220.363
Base S1a: 49 48 46.15541, 97 58 53.93487, 220.260
Base S2: 49 42 52.08990, 98 11 14.27833 , 265.333
Base S2a: 49 42 55.97045, 98 11 14.13693, 265.965


GPS Data Processing

All GPS phase data was post processed with continuous kinematic survey techniques using “On the Fly” (OTF) integer ambiguity resolution.  The GPS data was processed with forward and reverse processing algorithms.  The results from each process, using the data collected at the airport, were combined to yield a single fixed integer phase differential solution of the aircraft trajectory.   The differences between the forward to reverse solution within the project area were within project specifications (<10cm) in both the horizontal and vertical components, indicating a valid and accurate solution.

IMU Data Processing

An IMU (inertial measurement unit) was used to record precise changes in position and orientation of the LIDAR scanner at a rate of 200 Hz.  All IMU data was processed post flight with a filter to integrate inertial measurements and precise phase differential GPS positions.  The resulting solution contains geodetic position, omega, phi, kappa, and time for subsequent merging with the laser ranging information.