|2009 National Renewable Energy Labratory/Boston Redevelopment Authority Topographic
LiDAR: Boston, Massachusetts
||The Alliance for Sustainable Energy, LLC contracted with Sanborn to provide LiDAR
mapping services for the Boston area. Utilizing multi-return systems, Light Detection
and Ranging (LiDAR) data in the form of 3-dimensional positions of a dense set of
mass points was collected for approximately 90 square miles. All systems consist of
geodetic GPS positioning, orientation derived from high-end inertial sensors and high-accurate
lasers. The sensor is attached to the aircraft?s underside and emits rapid pulses
of light that are used to determine distances between the plane and terrain below.
Specifically, the Leica ALS-50 LiDAR system was used to collect data for the survey
campaign. The LiDAR system is calibrated by conducting flight passes over a known
ground surface before and after each LiDAR mission. During final data processing,
the calibration parameters are inserted into post-processing software. Lidar Acquisition
Parameters: Instrument: Leica ALS50 Flight Altitude: ~ 1500m AGL Airspeed: ~ 120 Knots
Scan Frequency: 46 Hertz Pulse Rate: 74,400 Hertz Scan Width Half Angle: 25 Degrees
Sidelap: 30% This Lidar survey acheived a point spacing of 1.0 meter.