Summary

Description

Terrapoint, on behalf of multiple agencies, collected topographic lidar of the Lower Columbia River area. Field data collection took place between the dates of January 10th and February 20th, 2005. The control network and checkpoint surveys were performed from January 4th to February 12th, 2005. The project area covers approximately 890 square miles along the Columbia River, from the Bonneville Dam to the Pacific Ocean. A total of 431 flightlines were required to cover the project area flightlines. Terrapoint used a 40 kHz Airborne Laser Terrain Mapping System ALTMS sensor attached to a Navajo Twin-engin aircraft (C-FVZM). The mission was flown at 3500 feet above ground level at an average speed of 140 knots. The system consists of a 36 degree full scan angle laser, a Trimble 4700 GPS receiver and a Honeywell H764 IMU unit. The nominal flightline spacing was 1070 feet with 30 to 50% sidelap. The surveyed and processed data was received divided by funding agency. The agency responsible for funding each tile is represented as a number (0:COE, 1:DNR, 2:DOGAMI, 3:DOI) in the "User Data" field of each LAS file.