The primary goal of hydrographic survey is to measure and describe features of the seabed and coastal areas in order to maintain safe navigation and marine activity. Key tools in hydrographic survey these days are multibeam and interferometric sonars, which provide millions of measurements, or soundings, of the seafloor, and airborne LiDAR, providing nearly as dense datasets in coastal and shallow waters. This dense data must be quickly evaluated, processed, decimated, and made into products such as Electronic Navigation Charts that can be used by mariners.
Fledermaus is used thoughout the hydrographic survey. During data acquisition and quality control stages, data can be quickly loaded and visualized to evaluate the quality of the data and rapidly identify artifacts, in 3D. During processing, the Fledermaus software has direct read and unload to a variety of sonar, software, and agency specific formats including QINSy QPD, GSF, CARIS HIPS & SIPS HDCS, Hypack HS2, Kongsberg ALL, ATLAS SURF, AHS HTF, FAU, NGA B93, LAS, and SMA BDI.
True 64-bit software, use of multiple processors,CUBEThe CUBE algorithm was developed by Dr. Brian Calder at the Center for Coastal and Ocean Mapping/Joint Hydrographic Center at the University of New Hampshireand Area Based processing methods are utilized to shorten processing time and quickly take your data
from unrefined survey data to the best possible seabed surface model, with higher confidence that your model is based on real data, not collection artifacts. Additional grids, draped imagery, nautical charts, contours, Electronic Nautical Charts, and other information can be added to support your processing. Once data is refined to a clean sounding or point set, Fledermaus has the tools you need to produce your survey report and products. Sounding-selection for charting or shoal-biased thinning can quickly be performed on the data using approved filters and algorithms; as you compile your feature reports, you can consult the multibeam water column data over wrecks and hazards to be sure the least-depths were detected. Bathymetric Attributed Grids (BAG) with proper metadata, survey area polygons, and Sounding Density Surfaces can be generated to show coverage and for quality assurance. Finally, your data must be databased and chart products must be created. Fledermaus’s direct integration to ArcGIS® Geodatabases and theEsri ArcGIS For MaritimeArcGIS® trademark provided under license from Esricreates a seamless transition from data to archiving and products.
For examples of Fledermaus being used by an agency doing hydrographic surveys, see the UK Marine Coast Guard Agency's Hydrography page, especially the CHP Survey Results page.
Data courtesy of MCA (Maritime and Coastguard Agency) and MMT Group