The AverageGridder module of Fledermaus 6.0 (IVS, Inc) was used to create a 1m cell-size surface model (grid) from the 1m xyz ASCII text file exported from Caris HIPS. Because the HIPS xyz file contained positive z values, z was inverted when creating the grid. The grid was created using the weighted moving average method with a weight diameter of 3 cells. The grid was exported from AverageGridder as Fledermaus dtm/geo files, and imported into the DMagic module of Fledermaus 6.0 for surface shading and assembly into a Fledermaus data object (sd file). The Dmagic surface shader tool was used to create a shade file (illumination azimuth = 315°, shadow length = 0) and this was combined with the dtm and geo files to produce an sd file. The sd file was examined carefully in the Fledermaus 3-d environment to locate artifacts and other portions of the data needing further cleaning. Caris HIPS was used to re-edit the original multibeam swath data in an attempt to correct any issues found in Fledermaus, and a new 1m xyz file was exported from HIPS. The surface model creation and inspection process was then repeated using the new xyz file, and the entire HIPS-Fledermaus process was repeated iteratively, until the final surface model was judged to be as clean and free of artifacts as possible.
