Airborne Doppler lidar investigation of the wind-modulated sea-surface angular retroreflectance signature

Tratt, David M.; Menzies, Robert T.; Chiao, Meng P.; Cutten, Dean R.; Rothermel, Jeffry; Hardesty, R. Michael; Howell, James N.; Durden, Stephen L.

doi:10.1364/ao.41.006941

Cited by 11 publications

(9 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This specular reflection depends on the instantaneous angle defined by the light source, the water surface, and the camera, and also the relative angle between the direction of wave propagation and the camera [ Stilwell , 1969]. In contrast, the bubbly water surface produced by wave breaking is generally treated as an isotropic (Lambertian) scattering surface for the visible band of light [ Gordon and Jacobs , 1977; Tratt et al , 2002].…”

Section: Some Previous Workmentioning

confidence: 99%

Remote sensing of wave roller lengths in the laboratory

Haller

Catalán

2009

J. Geophys. Res.

View full text Add to dashboard Cite

[1] The optical intensity signals from surf zone waves in a laboratory flume are analyzed using several different phase-averaging techniques, and a methodology is developed for estimating wave roller lengths and local wave dissipation. The intensity signals (i.e., phase-averaged intensity profiles) of individual breaking waves are compared with the wave profiles measured by in situ wave gauges, and the optical signal of the wave roller is shown to ramp up from the toe of the wave roller on the front face of the wave to a maximum intensity at the wave crest. The remote sensing observations capture the growth, equilibrium, and decay phases of the roller as it propagates over a fixed bed arranged in a bar/trough morphology. Next, for the regular wave conditions considered here, the local maxima of the phase-averaged intensities are shown to better indicate the initial onset of wave breaking and the occurrence of wave breaking in the bar trough, as compared to the more commonly used time-averaged mean intensity. In addition, the phase-averaged profiles are used to measure the size of the roller, and these measurements are compared to previous observations of smaller-scale rollers in equilibrium. The observed roller lengths are shown to agree with predictions from a wave roller model and to provide a new physical link between the remotely sensed signal and roller dissipation. Finally, as an example application of these new data, a simple wave height inversion model is presented that allows an estimation of surf zone wave heights from the remotely sensed roller lengths.

show abstract

Section: Some Previous Workmentioning

confidence: 99%

Remote sensing of wave roller lengths in the laboratory

Haller

Catalán

2009

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…The only varied parameter was the wind speed, which was set to 2, 5, and 10 m∕s, respectively. The results of the wave simulations were obtained for waves over an area of 400 × 400 m 2 , sampled spatially with a 1-m resolution and a time resolution of 1 Hz for duration of 3 s. The reflection model of the sea surface follows that of Tratt et al 21 The sensor height was assumed to be 15 m above sea level, which corresponds to a maximum viewing range to the surface of 14 km. Since the ranges studied were shorter (3 to 8 km) we omitted the effect of the earth's curvature.…”

Section: Modeling Effortsmentioning

confidence: 99%

Simulation and modeling of laser range profiling and imaging of small surface vessels

2014

View full text Add to dashboard Cite

The detection and classification of small surface targets at long ranges is a growing need for naval security. Simulations of a laser radar at 1.5 μm aimed for search, detect, and recognition of small maritime targets will be discussed. The data for the laser radar system will be based on present and realistic future technology. The simulated data generate signal waveforms for every pixel in the sensor field-of-view. From these we can also generate two-dimensional (2-D) and three-dimensional (3-D) range and intensity images. The simulations will incorporate typical target movements at different sea states, vessel courses, effects of the atmospheric turbulence and also include different beam jitter. The laser pulse energy, repetition rate as well as the receiver and detector parameters have been the same during the simulations. We have also used a high resolution (sub centimeter) laser radar based on time correlated single photon counting to acquire examples of range profiles from different small model ships. The collected waveforms are compared with simulated wave forms based on 3-D models of the ships. A discussion of the classification potential based on information in 1-D, 2-D, and 3-D data separately and in combination is made versus different environmental conditions and system parameters.

show abstract

“…Specular reflection decreases as wave steepness increases and is extremely large in very calm waters. Hu et al [24], citing Platt [26], Menzies et al [27], and Tratt et al [28], modeled the specular surface reflection as:…”

Section: Specular Surface Reflectionmentioning

confidence: 99%

Sensitivity of Depth-Integrated Satellite Lidar to Subaqueous Scattering

Barton

Jasinski

2011

Remote Sensing

View full text Add to dashboard Cite

Abstract:A method is presented for estimating subaqueous integrated backscatter using near-nadir viewing satellite lidar. The algorithm takes into account specular reflection of laser light, laser scattering by wind-generated foam as well as sun glint and solar scattering from foam. The formulation is insensitive to the estimate of wind speed but sensitive to the estimate of transmittance used in the atmospheric correction. As a case study, CALIOP data over Tampa Bay were compared to MODIS 645 nm remote sensing reflectance, which previously has been shown to be nearly linearly related to turbidity. The results indicate good correlation on nearly all CALIOP cloud-free dates during the period 2006 through 2007, particularly those with relatively high atmospheric transmittance. The correlation decreases when data are composited over all dates but is still statistically significant, a possible indication of variability in the biogeochemical composition in the water. Overall, the favorable results show promise for the application of satellite lidar integrated backscatter in providing information about subsurface backscatter properties, which can be extracted using appropriate models.

show abstract

Airborne Doppler lidar investigation of the wind-modulated sea-surface angular retroreflectance signature

Cited by 11 publications

References 37 publications

Remote sensing of wave roller lengths in the laboratory

Remote sensing of wave roller lengths in the laboratory

Simulation and modeling of laser range profiling and imaging of small surface vessels

Sensitivity of Depth-Integrated Satellite Lidar to Subaqueous Scattering

Contact Info

Product

Resources

About