Abstract
Some errors and noises are often present in multibeam swath bathymetric data. Echo detection error (EDE) is one of the main errors. It causes the depth error to become bigger in outer beams and looks like sound refraction. But depth errors due to EDEs have a trumpet-shaped appearance, instead of a curved appearance that is caused by the sound refraction errors. EDEs, including systematic acoustic signal detection errors and internal noises, cannot be removed during the correction of sound refraction. It causes depth inconsistencies between adjacent swaths and degrades precision of outer beams. Sometimes, the bathymetric errors caused by EDEs do not even meet the requirements of IHO (International Hydrographic Organization). Therefore, a post-processing method is presented to minimize the EDEs by filtering outliers and compressing outer beams of multibeam bathymetric data. The outliers caused by internal noises are removed by an automatic filter algorithm first. Then the outer beams are compressed to reduce systematic acoustic signal detection errors according to their depths, the calculated depth line and standard deviations (SDs). The automatic filter process is important for calculating the depth line. The selection of inner beams to calculate the average SD of beam depths is crucial to achieving compressing goals. The quality of final bathymetric data in outer beams can be improved by these steps. The method is verified by a field test.
Similar content being viewed by others
References
Cartwright D (2003) Multibeam bathymetric surveys in the Fraser River Delta, managing severe acoustic refraction issues, M.E. Thesis, University of New Brunswick, Canada
Cartwright D, Clarke JE (2002) Multibeam surveys of the Frazer River Delta, coping with an extreme refraction environment. In: Proceedings of canadian hydrographic conference, Montreal, Canada
Church I, Clarke JE, Haigh S, Santos M, Lamplugh M, Griffin J, Parrott R (2008) Using globally-corrected GPS solutions to assess the viability of hydrodynamic modeling in the bay of Fundy. In: Proceedings of the Canadian hydrographic conference and national surveyors conference, Victoria, BC, pp 4–2
Clarke J (2003) Dynamic motion residuals in swath sonar data: ironing out the creases. Int Hydrogr Rev 4(1):6–23
Clarke J (2006) Applications of multibeam water column imaging for hydrographic survey. Hydrogr J 4:1–33
Colombo OL, Evans AG, Vigo-Aquiar MI, et al (2000) Long-baseline (>1000 km), sub-decimeter kinematic positioning of buoys at sea with potential application to deep-sea studies. In: ION-GPS, Salt Lake City, UTah, Sep. 19–23
Kammerer E (2000) A new method for the removal of refraction artifacts in multibeam echosounder systems, Ph. D. Thesis, University of New Brunswick, Canada
Kammerer E, Clarke JE, Locat J, Doucet N, Godin A (1998) Monitoring temporal changes in seabed morphology and composition using multibeam sonars: a case study of the 1996 Saguenay River floods. In: Proceedings Canadian hydrographic conference 1998, Victoria, pp 450–461
L-3 Communications SeaBeam Instruments (2000) http://www.ldeo.columbia.edu/res/pi/MB-System/sonarfunction/SeaBeamMultibeamTheoryOperation.pdf
Yang F, Li J, Wu Z et al (2007) A post-processing method for the removal of refraction artifacts in multibeam bathymetry data. Mar Geodesy 30(3):235–247
Acknowledgments
The authors thank Prof. Yongqi Chen of the Hong Kong Polytechnic University for the constructive comments and polishing the English of the text. This work was supported by the project of Shandong Provincial National Science Foundation for Distinguished Young Scholars (Grant No. JQ201113) and SDUST’s National Science Foundation for Distinguished Young Scholars (Grant No. 2010KYJQ102). We are grateful to the anonymous reviewers who carefully read our manuscript and helped us improve it.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Yang, F., Li, J., Han, L. et al. The filtering and compressing of outer beams to multibeam bathymetric data. Mar Geophys Res 34, 17–24 (2013). https://doi.org/10.1007/s11001-012-9164-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11001-012-9164-2