Multibeam bathymetry data collected by the U.S. Geological Survey in the Bering Sea in 2011 during cruise MGL1111, along-track center-beam depths extracted from 100-meter gridded data in plain text format, geographic coordinates.

CARIS processing for MGL1111: A new CARIS HIPS project (ver. 7.1) was created with projection information set to Universal Transverse Mercator (UTM) Zone 60N, WGS84. Each Simrad EM122 data file (*.all) was imported to the new CARIS project using the Import/Conversion Wizard. A 100 meter resolution Bathymetric and Statistical Error (BASE) Surface was created and new files were added to the surface each Julian day. With the addition of new files, the BASE surface was reviewed for any inconsistencies or data anomalies. Navigation was edited as needed using the navigation editor tool in CARIS. Filters were applied to each line including beam to beam slopes and across track angle. The CARIS "surface filter" was applied to the data using the two standard deviation option. Swath data were also edited manually to remove obviously outlying soundings.

The 100 meter CARIS HIPS BASE surface for MGL1111 was exported from CARIS as a Bathymetric Attributed Grid (BAG) file. The resulting BAG file was used to import the surface into IVS3D DMagic as gridded data, then the surface was saved as a Fledermaus Digital Terrain Model in the IVS3D SD format. Finally, the Fledermaus ArcGIS module was used to export the surface directly to an ESRI Binary Grid.

Navigation information (Easting,Northing,Longitude,Latitude,UTC Time,Year-Julian Day,SIS Filename) were extracted from the CARIS HIPS database utilizing a Perl script that ran the CARIS command 'printfnav' on all edited EM122 data files. Unix 'cat' was used to concatenate the output nav files to a single file, 'grep' was used to extract only soundings flagged as accepted, then an 'awk' filter was used to extract records with unique navigation fixes, one per second. The resultant text file was used to create an ArcGIS point feature class (ArcMap, create feature class from XY table).

The navigation text file created in the previous step was used to create an ArcGIS point feature class (ArcMap, create feature class from XY table). The navigation point feature class and the ESRI binary grid 'MGL1111_bathy' were used as the point and raster inputs for the ArcGIS Spatial Analyst tool 'Extract values to points', with the interpolate values at point locations option selected. The resultant point shapefile containing "Easting,Northing,Longitude,Latitude,UTC Time,Year-Julian Day,SIS Filename,Depth (meters)" was exported to ASCII text.

The file was was re-sorted on the basis of columns JDYR and UTC to ensure chronological order.

Metadata was modified to bring up to current USGS PCMSC standards. Point of Contact and Metadata Contact information was updated. Keywords were added and refined. Cross Reference citation added. Details about different Network Resource Name links was given in the Access Instructions section. Minor typos were corrected. No data information was changed.