SEAVIEW SENSING TECHNOLOGY

/ SOFTWARE OVERVIEW
Seaview Realtime software is an integrated wave, current and wind measurement package, with data viewer, web access facilities, auto-diagnostics for the radar and environmental warning systems.

The software takes in the Doppler spectra from the HF radar and provides the met-ocean data in real-time locally or on-line. (Comparison of types of radar)

Surface currents are measured from the frequencies of the two main peaks in the radar power spectrum at each grid point across the coverage area.

Wind directions are measured from the amplitudes of the two main peaks in the radar power spectrum at each grid point across the coverage area.

Seaview software calculates wave data by numerical inversion of an equation relating the radar power spectrum (the measured quantity) to the ocean wave directional spectrum (the solution of this inversion). This is based on the theory developed by Barrick in the 1970s which provides a good description of the backscattered signal over the full range of HF radar frequencies in low sea states and for low HF frequencies in high sea states. Parameters such as significant waveheight, peak period and direction are obtained from the directional spectrum. Simple empirical formulae can also be used for some parameters when inversion is not possible. Seaview offers a full directional spectrum for each grid point across the coverage area arguably offering more accurate wave data than other radar systems.

Inversion times are around 1/6 of a second per cell, which mean that the software calculates the met-ocean data in less than one minute for an inversion of 300 grid points or measurement cells. The package is designed to be portable across POSIX.1 conforming operating systems and has been successfully run on Solaris-Sparc and Linux-x86 systems.

Seaview Reatime is available as an operational system with a file and web server function or as a stand alone package for offline processing. This version and its predecessors have been used with data from the OSCR, WERA and Pisces HF radar systems in experiments in the Netherlands, Norway, Spain, France, Oman, the USA, Australia and the UK. In 2005 the software was used with a Pisces Radar for the UK Met Office in the Celtic Sea for possible inclusion of HF radar in the DEFRA wave monitoring network, WAVENET and with a WERA radar at the Proudman Oceanographic Laboratory Coastal Observatory in Liverpool Bay. In 2006 the software was used with WERA HF radar systems in deployments for the French Naval Oceanographic Center and the Oman Met Office. In 2007 the software was installed for a WERA system, part of the Australian ACORN network.

Software platforms: