Airborne Coastal Current Evaluation Survey System
Abstract
PURPOSE: This Technical Note introduces a new method for collecting current measurements at multiple locations in a localized region over a short period of time. This new method can provide qualitative spatial resolution of bottom current patterns and can be operated near structures, in high energy regimes, and in shallow or quickly changing bathymetry. BACKGROUND: In order to better understand coastal 'processes and evaluate or predict the effect of placing a structure in the nearshore, current patterns need to be examined. Dye studies are valuable in delineating only surface or nearsurface currents. Prior to development of the Airborne Coastal Current Evaluation Survey System (ACCESS) , spatial resolution of bottom current patterns required placement of an entire suite of instruments to blanket an area and collect data simultaneously. Often this stationary bottom current acquisition technique was ruled out because of the enormous expense associated with placement and maintenance of the large array of meters. Another option is to use several boats and instruments to collect this data, but boats are often limited by bathymetry, wave and current conditions, or inability to navigate about structures. The ACCESS technique may be applicable to many situations where these limitations have previously prevented collection of current information. Initial deployments of ACCESS used an S-4 InterOcean Inc. electromagnetic current meter, suspended by cable from a helicopter to measure currents at several locations within a short period of time. to create a qualitative mosaic of local current patterns. This technique was developed at the Coastal Engineering Research Center (CERC) as part of the Monitoring of Completed Coastal Projects (MCCP) research program's Siuslaw River, Oregon project. The helicopter was selected as the work platform because of its ability to quickly transit between measurement sites and to operate in high energy, nearshore zones and around structures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1992
- Accession Number
- ADA609826
Entities
Organizations
- Coastal Engineering Research Center