SEAVIEW SENSING TECHNOLOGY

/ SOFTWARE SPECIFICATION
Seaview Realtime software is portable across platforms and is suitable for use with most beam-forming HF radars.

The system performance and specification will depend on the radar hardware selected for use with Seaview software and the individual installation. The details below are given for typical installations on two types of radar — a WERA supplied by Helzel Messtechnik GmbH and a Pisces supplied by Neptune Radar Ltd.

  Software Features
Met-ocean data Wave, current & wind measurements at each possible grid point across coverage area
Data Viewer Maps, time series and wave spectrum plots with download facility
Radar diagnostics Radar diagnostics including measurements of: signal level & noise level time series and maps, Doppler spectrum, inversion quality and data file delivery process.
Environmental warnings Software may be customised for particular applications, for example, to provide text message alerts for storm surges.

System Features Installed with WERA radar Installed with Pisces radar
Range 20km for waves – 40km for currents at 27MHz. Most WERA installations are now at lower frequencies. >100km for waves, up to 200km for currents
Spatial resolution Typically 1km Depends on radar parameters, typically 7–15km
Temporal Resolution 10 minutes 1 hour

Data Measurement WERA 'accuracy'
at 27MHz, compared with EuroROSE 'sea-truth' for 2 different experiments
Pisces 'accuracy'
compared with WAVENET 'sea-truth' for 2 different seasons
surface current current speed: 8 cm/sec (Provided by Helzel) current speed: 6 cm/sec (Radar precision implied from tidal component comparison with 2-D model)
significant waveheight mean differences 16–20cm
relative bias 6%
standard deviation <17%.
Maximum 6m
mean differences 6–11cm
relative bias 2.5–8%
standard deviation <45%.
Minimum 1m
wave period mean differences 1.1–1.4s
standard deviation 1.7–1.8s
mean differences 0.2s
standard deviation 1.1–1.3s
mean direction mean difference 2°,
standard deviation 28°.
mean difference 5-12°,
standard deviation 33-37°.
other integrated parameters depends on frequency range of integration, type of parameters, significant waveheight depends on frequency range of integration, type of parameters, significant waveheight
directional spectrum not assessed, resolution: 0.01Hz and 15° to a maximum frequency which depends on radar frequency being around 0.25Hz at 6MHz and around 0.35Hz at 30MHz not assessed, resolution: 0.01Hz and 15° to a maximum frequency which depends on radar frequency being around 0.25Hz at 6MHz and around 0.35Hz at 30MHz
partitioned parameters not assessed not assessed
wind direction mean difference 12° standard deviation 33° (not collocated with onshore measurement) mean difference 8° deviation 43° (collocated with model winds)
wind speed not assessed not assessed

1 Validation and inter-comparisons of wave measurements and models during the EuroROSE experiment, Wyatt et al, Coastal Engineering 48, 2003.

2 Operational wave, current and wind measurements with the Pisces HF radar, Wyatt et al, IEEE Journal of Oceanic Engineering, 31, 819–834.

3 The range depends on radio frequency used, being longer at lower frequencies. The range of the radar may also be affected by the coastal terrain at the installation site, the salinity of the sea and the sea state — at significant wave heights above 2m there may be some reduction in maximum range capability.