Installation

In the initial phase of a project, Deltares prepares a station design on the basis of the client monitoring needs. Key parameters are the number of cameras, type of lenses and the elevation of the video station. The optimum station design depends on the visibility of the phenomena of interest (for instance migration of shoals, shoreline erosion, currents, etc), the local pixel resolution (hence distance to the video station) and the extent of the overall field of view. Results are provided to the client by means of plan-view pixel resolution maps and camera contours in GIS format. Prior to installation in the field, the client selects and prepares the location where the Argus video system will be installed. During this phase, Deltares is available for consult on beneficial site characteristics and the optimal choice. Such an installation location should at least provide:

• A suitable space for the image collection computer and video (excluding cameras) and communication equipment, to protect the equipment against the elements (rain, wind, fog, heat). The distance from the cameras to the computer is ideally less than 8 m. Larger distances can be bridged with the help of a fiber-optic link.
• Appropriate, mechanically stable and secure mounting positions for the camera housings
• A stable 120/240VAC 10A 50/60Hz power supply in the equipment space (Actual current requirements are less).
• Communication infrastructure (analog, ISDN or ADSL) between the collection and archive (our server in Delft) computers.

Experience has learned that installations on top of buildings have proven to be most robust in terms of data collection and minimal maintenance needs. However, present-day technology allows for the installation of very remote or temporary stations, operated by a laptop-computer and driven by solar and/or wind power. The installation procedure includes the survey of the camera locations (estimated location of the lens within 10 cm) and a set of so-called Ground Control Points. These GCP's are well-visible features, which can easily be identified at the images obtained from the different cameras. They are needed to find the relationship between image and field coordinates for each camera. This relationship is described by means of a so-called geometry solution. With the help of such a geometry solution, the real-world location of image features can be determined. Geometry solutions need to be updated after a change of camera orientation, for example after cleaning of the lenses. Communication protocols between the archive computer and the field station are tested and data collection schemes are specified. A www-interface is installed for image viewing. By the end of the installation phase, video data can be accessed by the client. Once the station is operational, the client will be responsible for on-site maintenance. In case of complicated or software-related problems, Deltares will provide remote assistance.