Argus video

11. ARGUS VIDEO

Using digital imaging technology, shore-based video systems now provide the additional capability of automated data collection, encompassing a much greater range of time and spatial scales than were previously possible. An ARGUS monitoring system typically consists of four to five video cameras, spanning a 180º view, and allowing full coverage of about four to six kilometers of beach. The cameras are mounted on a high location along the coast and connected to an ordinary PC on site, which in turn communicates to the outside world using conventional techniques such as analog modems, ISDN, DSL, or a wireless LAN. Data sampling is usually hourly (although any schedule can be specified) and continues during rough weather conditions. As the process of data collection is fully automated, the marginal operating costs are virtually zero. Each standard hourly collection usually consists of three types of images: 1) snapshot images, 2) time exposure images averaging out natural modulations in wave breaking to reveal a smooth pattern of bright image intensities, which are an excellent proxy for the underlying, submerged sand bar topography and 3) variance images helping to identify regions which are changing in time (like the sea surface).