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A Comparison of SIR-B Directional Ocean Wave Spectra with Aircraft Scanning Radar Spectra
Science (New York, N.Y.)
|June 20, 1986
Summary
Shuttle Imaging Radar-B (SIR-B) data accurately estimated ocean wave characteristics, including wavelength and direction, when compared to airborne radar. Wave models showed directional bias, highlighting the value of satellite radar for ocean wave research.
Area of Science:
- Oceanography
- Remote Sensing
- Geophysics
Background:
- Directional ocean wave spectra are crucial for understanding wave dynamics and their impact on marine activities.
- Satellite-borne radar systems offer a unique perspective for remote sensing of ocean surface conditions.
Purpose of the Study:
- To compare directional ocean wave spectra derived from Shuttle Imaging Radar-B (SIR-B) L-band imagery with independent airborne radar estimates.
- To evaluate the accuracy of SIR-B in capturing wave parameters like wavelength, direction, and spectral shape.
Main Methods:
- Analysis of SIR-B L-band imagery collected over the Pacific Ocean off Chile.
- Comparison of SIR-B-derived wave spectra with data from two airborne scanning radars.
- Validation against a U.S. Navy global spectral ocean wave model prediction.
Main Results:
- SIR-B-derived spectra provided reasonable estimates of wavelengths, directions, and spectral shapes for sea states with significant wave heights from 3 to 5 meters.
- SIR-B image intensity variance spectra closely matched aircraft slope variance spectra for range-traveling waves.
- The U.S. Navy wave model showed no significant bias in dominant wave number but a directional bias of approximately 30 degrees.
Conclusions:
- SIR-B L-band imagery is a valuable tool for deriving directional ocean wave spectra.
- SIR-B data can accurately characterize various wave systems, including purely azimuth-traveling waves.
- Discrepancies with wave models highlight areas for model improvement in directional wave prediction.
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