Point of Beginning - October 2009 - (Page 24)

BY CRAIG R. DYLAN hen record storm surges hit New Orleans and breached the 17th Street Canal levee in the wake of Hurricane Katrina at the end of August 2005, experts knew the situation was bad. “I was watching it on TV from where I’d evacuated, and I couldn’t believe it at first,” says Mark W. Huber with the U.S. Army Corps of Engineers (USACE). “‘Life’s not going to be the same now,’ I thought.” W Louisiana’s GULFNet provides reliable elevations when it really matters. Huber and others in the USACE immediately began organizing emergency survey operations that would continue for months. Jimmy Chustz, PLS, president of Chustz Surveying Inc. in New Roads, La., a private survey firm under contract to the USACE, may have been the first surveyor to get to New Orleans following the disaster. “It was devastating to watch it all happen,” he says. “The first thing I thought was that we needed to get in there immediately.” Prior to Katrina, Chustz had stored boats and other equipment in a flood-proof location away from trees, which allowed his crew to deploy rapidly. “The levee broke on Monday, and we were there Tuesday morning,” he says. 24 OCTOBER 2009 | Point of Beginning | www.pobonline.com However, once the surveyors arrived, they faced another challenge. The entire city was under water, including key bench marks, and most of the region’s monumentation was known to be off vertically by nearly a foot due to subsidence. What’s more, Louisiana State University’s (LSU) GULFNet, a network of continuously operating reference stations (CORS), had been hit hard by the storm conditions. “Some stations were blown down; others had lost power. And just getting to them was difficult because roads had been washed out,” says Roy Dokka, PhD, the LSU civil and environmental engineering professor who originally conceived GULFNet. A team from LSU headed by Tony Cavell, PLS, and other volunteers scrambled behind the scenes to re-establish the network. Receivers were repaired and replaced; solar panels were installed to provide emergency power, and satellite uplinks were established. Within one to two days, individual reference stations were once again operational, and the entire network was functioning within two weeks. One important post-Katrina adjustment was relatively easy. Critical early survey tasks included damage assessment and the location of navigational hazards, and airborne surveying was the quickest way to get this work done. To improve the accuracy of airborne LiDAR, photogrammetric surveys and aerial photography, the USACE asked Dokka if he could increase the sampling rate of GULFNet’s reference http://www.pobonline.com

Table of Contents for the Digital Edition of Point of Beginning - October 2009

Point of Beginning - October 2009
Web Site/Digital Edition Contents
Editor’s Points
Control on the Edge
Hurricane Watch
The Need for Speed
A Digital Desert
31 Degrees of Latitude
Taming the Wild GIS
The Magic Bullet
From the Ground Up
Professional Topography
Safety Sense
The Business Side
New & Notable
Classified Ads
Fun & Games
Ad Index

Point of Beginning - October 2009