Article Type:
Research Article

Shallow Angle Wave Profiling Lidar

M. R. Belmont School of Engineering, Computer Science and Mathematics, University of Exeter, Devon, United Kingdom

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J. M. K. Horwood School of Engineering, Computer Science and Mathematics, University of Exeter, Devon, United Kingdom

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R. W. F. Thurley School of Engineering, Computer Science and Mathematics, University of Exeter, Devon, United Kingdom

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J. Baker School of Engineering, Computer Science and Mathematics, University of Exeter, Devon, United Kingdom

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Print Publication:
01 Jun 2007
DOI:
https://doi.org/10.1175/JTECH2032.1
Page(s):
1150–1156
Restricted access

Abstract

A lidar scanning system is described that is primarily designed to measure sea wave shape. The device is capable of measuring real-time spatial profiles over distances of hundreds of meters, and as the lidar must inevitably operate from modest elevations (e.g., from a vessel’s masthead), it is inherently a very shallow angle metrology device. This results in a highly nonuniform distribution of the wave elevation values. The vertical and horizontal resolution is primarily set by the characteristics of the optical system employed and range/data capacity is set by signal-to-noise ratio considerations. Illustrative data are presented as consecutive profiles taken 0.2 s apart for highly trochoidal waves under conditions where the height was recorded to ±0.03 m and horizontal sample separation to ±0.025 m. A comparison is presented with traditional wave staff measurements.

Corresponding author address: Dr. Michael Richard Belmont, School of Engineering, Computer Science and Math, University of Exeter, EX4 5EB Exeter, United Kingdom. Email: m.r.Belmont@exeter.ac.uk

Abstract

A lidar scanning system is described that is primarily designed to measure sea wave shape. The device is capable of measuring real-time spatial profiles over distances of hundreds of meters, and as the lidar must inevitably operate from modest elevations (e.g., from a vessel’s masthead), it is inherently a very shallow angle metrology device. This results in a highly nonuniform distribution of the wave elevation values. The vertical and horizontal resolution is primarily set by the characteristics of the optical system employed and range/data capacity is set by signal-to-noise ratio considerations. Illustrative data are presented as consecutive profiles taken 0.2 s apart for highly trochoidal waves under conditions where the height was recorded to ±0.03 m and horizontal sample separation to ±0.025 m. A comparison is presented with traditional wave staff measurements.

Corresponding author address: Dr. Michael Richard Belmont, School of Engineering, Computer Science and Math, University of Exeter, EX4 5EB Exeter, United Kingdom. Email: m.r.Belmont@exeter.ac.uk

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Cover Journal of Atmospheric and Oceanic Technology
Journal of Atmospheric and Oceanic Technology

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