U.S. Army Funds Stevens' Laser-Mapping Robots
At the 2009 IEEE International Conference on Technologies for Practical Robot Applications, a vehicle called ROAMS demonstrated a cheap approach to mobile mapmaking
ROAMS (Remotely Operated and Autonomous Mapping System) was created by researchers at Stevens Institute of Technology in Hoboken, New Jersey, with funding from the U.S. Army.
The system uses several existing mapping technologies to build 3-D color maps of its surroundings. It uses a 2-D LiDAR sensor on a pivoting rotation frame. While the system has a lower resolution than a regular 3-D LiDAR, it could still be used for low-cost architectural surveying and mapmaking in military situations, the researchers say. The prototype system's cost is around $15,000 to $20,000.
The system takes about 30 seconds to scan a 160-meter-wide area. A color camera, also on the rotating frame, provides color information that is added to the map later on. The Stevens researchers developed a way to maintain the same resolution by automatically adjusting the scanning process depending on the proximity of objects. A human operator rides in a larger vehicle that follows the robotic one from up to a mile away.
AEP Embraces LiDAR
American Electric Power (AEP) has more than 5 million customers in 11 states, with more than 39,000 miles of transmission lines. In 2007, AEP began the undertaking of the North American Electric Reliability Corporation (NERC ) compliance regarding vegetation management. AEP was seeking a more accurate, consistent and timely solution for complying with NERC rules, while gaining demonstrative operational benefits that would allow the enterprise to better understand and protect its infrastructure.
AEP selected Utility Risk Management Corp. (URMC) and its partner ArborMetrics Solutions to undertake an extensive proof-of-concept to substantiate the accuracy, speed and costs of URMC's LiDAR-enabled asset inventory system.
“The LiDAR-based vegetation database allows the utility to set the criteria for vegetation management, query and manage all events accordingly,” said Vesa Leppanen, URMC's CTO. “There are millions of trees along and under the rights-of-way. Of that number, there might be several thousand that need more intensive analysis. From those thousands, perhaps several hundred need the attention of the tree crews. Database-driven management — based on accurate measurements covering the full census of vegetation — is truly the most cost-efficient method of utilizing limited resources.
“Utilities using LiDAR technology combined with sophisticated risk management software proved remarkably more accurate and faster than traditional labor-intensive methods of data gathering and work management,” stated Leppanen.
U.S. Geological Survey Shares LiDAR Report
U.S. Geological Survey Open-File Report 2009-1078 provides a comprehensive background into handling airborne LiDAR data. This document reviews procedures for the post-processing of Experimental Advanced Airborne Research LiDAR (EAARL) data using the Airborne LiDAR Processing System (ALPS), which was developed in an open-source programming environment operated on a Linux platform. ALPS also includes modules for the creation of bare earth, canopy-top and submerged topography digital elevation models. The EAARL system can be mounted in an array of small twin-engine aircraft that operate at 300 meters above ground level at a speed of 60 meters per second.
Transmission Line As-Builts
Surveying and Mapping Inc. (SAM Inc.) recently completed a low-altitude high-density LiDAR data, digital orthophotography and ground survey for 260 miles of transmission lines in north and east Texas.
LiDAR data was collected using a helicopter-mounted LiDAR system capable of collecting 150,000 to 250,000 ranges per second at an altitude of 100 meters above the terrain. LiDAR point density on the ground was typically in excess of 70 points per square meter. LiDAR data was controlled using two onboard ABGPS receivers to measure XYZ, and a position orientation system to measure inertial measurement units.
SAM Inc. processed the data using Flip7 LiDAR processing software and provided PLS-CADD-compatible files using X, Y, Z and H code, and time coordinates for ground points, vegetation, obstructions, structures and conductor/wires in accordance with the client's standard survey feature code descriptions.
