Post Hurricane Ike Emergency Call-out Clearance Surveys Various Locations, Texas

TerraSond organized a response team from field staff in Texas and staff diverted from other projects in Alaska, Washington and Louisiana, including an ongoing mapping debris project from Hurricane Katrina for NOAA. We also subcontracted five other Texas survey firms for the project. The initial response required a total of 17 survey vessels. Nine vessels were provided by TerraSond and its subcontractors, including two large offshore vessels that were chartered. The day after Hurricane Ike hit, all of the survey crews were at their assigned stations using single beam echosounders and side scan sonar systems. Survey crews conducted clearance surveys and located any obstacles to traffic. The single beam echosounders determined the depth while the side scan scanned the water to the left and right of each vessel. The vessels ran three lines down each channel in turning basins and anchorages to perform the clearance work.

Sounding data was processed by field crews using HYPACK software and transferred electronically to the processing staff in Alaska. The Alaska staff corrected the soundings using water-level data provided by the USACE, then created and managed the bathymetric surfaces generated from the soundings. XYZ files were georeferenced to soundings in the channels using the spacing specified by the USACE for clearance, then overlaid on existing nautical charts and .dxf files used for survey-channel planning. Side scan sonar data was monitored in real-time on the vessels, then transferred to TerraSond's Alaska office where obstructions to marine navigation were identified using Chesapeake Technolog's SonarWiz MAP software. These data were transferred to GIS maps, and printed in a PDF format to be uploaded to an FTP site. All work was completed overnight so that files could be accessed the following morning.

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