HR: 0800h
AN: OS11A-0478    [Abstracts]
TI: A Moored Airborne Video System with Nearshore Applications
AU: * Smith, G
EM: smith.3043@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 108 Scott Hall 1090 Carmack Road, Columbus, OH 43210 United States
AU: Lippmann, T
EM: lippmann.2@osu.edu
AF: The Ohio State University Byrd Polar Research Center, 108 Scott Hall 1090 Carmack Road, Columbus, OH 43210 United States
AB: Over the past two decades researchers have developed video-based remote sensing techniques to measure relevant nearshore variables. Measurements made include spatial patterns in sand bar morphology, run-up oscillations, wave breaking distributions, phase speed and wave angle, and most recently, surface currents within the surf zone and swash. In general, vertical (i.e., downward oriented) photography or videography is preferred to high-oblique land-based systems. However, although aircraft-mounted video systems have been under development for several years, the relatively high cost and short dwell time has limited its widespread application. Thus, most video measurements for research applications are obtained through methods whereby arrays of video cameras are fixed on land and oriented obliquely to the surf zone region of interest. The typically high-oblique imagery is limited in spatial ground coverage by rapidly degrading resolution in the far field, as well as lay-over problems associated with a fluctuating sea surface and high incidence look-angle. In order to alleviate these problems, researchers have attempted mounting video (or photographic) sensors on tethered balloons where long time series can be obtained over large regions of the surf zone without limiting resolution in the far field. In our research we have developed a technique for mounting a video system onboard a tethered helikite, a combination kite and helium-filled blimp (Allsopp Helikites, Ltd.). The video system consists of a downward-looking video camera in a custom weather-proof housing mounted on the keel of the helikite. Also included are a differential GPS receiver, tilt and heading sensor for accurate geometrical transformation, micro-processor, onboard power supply, and wireless data link. In this presentation, we will discuss the system in more detail, the image resolution and accuracies, and the expected applications to nearshore processes research. This work is sponsored by the Office of Naval Research.
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 4294 Instruments and techniques
DE: 4546 Nearshore processes
DE: 3020 Littoral processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting