Hillshaded-relief image produced from lead-line and single-beam sonar soundings, swath interferometric, multibeam, and lidar datasets (bb_navd88_hs_10m, Esri grid, UTM Zone 19N, WGS 84)

Collected the source datasets: NOAA data from NOS hydrographic surveys in the 1900s (lead-line and single-beam soundings) were downloaded from the NGDC website individually (http://maps.ngdc.noaa.gov/viewers/bathymetry/) in XYZ ASCII format; these data were in Geographic NAD83 horizontal datum and referenced to Mean Lower Low Water vertical datum. Data from NOAA NOS Hydrographic surveys conducted since 2000 were received directly from NGDC via personal communication and transfer of the CARIS HIPS/SIP HDCS directory (fully processed hydrographic survey data) by hard drive or FTP server. The 2000 era data used were in either XYZ or CARIS BASE surface format; these data were in UTM Zone 19N horizontal datum and referenced to Mean Lower Low Water vertical datum. The following NOAA NOS survey data were used: 1930s - H05622, H05628, H05630, H06445; 1950s - H06742, H08170; 1970s - H09615, H09628, H09644, H09645, H09646, H09647, H09661, H09668, H09669, H09712, H09724; 1990s - F00378, F00406, H10434, H10458, H10461, H10496, H10511, H10520, H10530, H10575; 2000s - H11076 (we received XYZ directly from NGDC), H11077 (we received XYZ directly from NGDC), H11318 (covered by USGS 2009/2010 data), H11319 (incorporated into USGS 2009/2010 data). Gridded data from surveys H11076 and H11077 can be downloaded in Esri grid format as listed in the Source Citations (NOAA Single-Beam Soundings).

USGS data from recent swath bathymetry surveys used the in-house CARIS HDCS data (final BASE surfaces that were exported to Esri format grids for the following projects/publications): Buzzards Bay OFR 2012-1002 (USGS Field Activities 2009-002-FA, 2010-004-FA, 2011-004-FA, NOAA Hydrographic Survey H11319); Red Brook Harbor OFR 2010-1091 (USGS Field Activity 2009-018-FA); Western Elizabeth Islands OFR 2011-1184 (USGS Field Activity 2010-003-FA); Elizabeth Islands OFR 2013-1020 (USGS Field Activity 2011-003). These data may be downloaded in Esri grid format as listed in the Source Citations (Poppe and others, 2007;Poppe and others, 2008; Pendleton and others, 2012; Turecek and others, 2012; Ackerman and others, 2013; Pendleton and others, 2014). These data are in UTM Zone 19N horizontal datum and referenced to Mean Lower Low Water vertical datum. US Army Corp of Engineerslidar data used the topobathy 32-bit GeoTIFFs that were received directly from USACOE; these data (Tiles 01, 02, 03 from 2005-2007 survey) are also available in LAS Lidar format via NOAA Digital Coast at (http://csc.noaa.gov/htdata/lidar1_z/geoid12a/data/116/)

Created CARIS Point Cloud CSAR files for all of the XYZ datasets using CARIS BASE Editor v4.0.5.

CARIS CSAR format surfaces were created for each of the individual point cloud dataset of the NOAA survey data: 1. Point cloud CSAR files were brought into CARIS BASE Editor 2. Create TIN from point cloud file 3. TIN Edge Removal process was run using the default parameters, usually twice. In few cases a "coverage hole" was manually digitized to ensure that the TIN did not extend across land/islands/shoals that were not mapped (these features were digitized off a NOAA nautical chart). 4. Interpolate Surface from TIN (results in a ***_surface.csar file for each point cloud dataset) 5. Point cloud files and surface files were grouped by decade in BASE Editor for ease of data management. 6. The "Data End Date" property for each survey surface was populated with the final survey day for each hydrographic survey on the basis of information from the NOAA Descriptive Reports.

Combined all the data sources in CARIS BASE Editor (Tools -> Surfaces -> Combine...) 1. (General). Choose all the surfaces to include, set output CSAR filename (D:\BuzzardsBay\Bathy_working\output_csar\BB_Combine_ALL_2Aug2013.csar) 2. (Options). Choose Horizontal Coordinate system - UTM - WGS84 Zone 19N (Key UTM-19N), Resolution = 10m, Name of primary z layer = "depth" 3. (Extent). Zoom out to the full extent of the input datasets and use the cross-hair to set the output extent 4. (Conflicts). Imported the conflict file rule_NewestPriority.crfx which was created in this dialogue previously and defines the rule to use as "Where the attribute EndDate is greatest" meaning that priority goes to the dataset with the more recent Data End Date value in the case of overlapping data.

Exported the combined CSAR grid to XYZ file (BB_Combine_ALL_22Aug2013.xyz.txt)

Using VDatum - NOAA's Vertical Datum Transformation 3.2, converted from MLLW to NAVD88 vertical datum (BB_Combine_ALL_22Aug2013Nodata.xyz.txt)

In CARIS BASE Editor v4.0.5: Created a CSAR from the new XYZ grid with NAVD88 heights (BB_Combine_ALL_22Aug2013Nodata.xyz.csar)

In Global Mapper v14.2.5: Converted ACOE LiDAR 32-bit GeoTIFFs to gridded XYZ, then exported XYZ file (LIDAR_XYZ_fromGlobalMapper.xyz)

In CARIS BASE Editor v4.0.5: imported LiDAR XYZ file to create CSAR grid (LIDAR_XYZ_fromGlobalMapper.csar) then combined the bathy data (BB_Combine_ALL_22Aug2013Nodata.xyz.csar) with the LIDAR data (LIDAR_XYZ_fromGlobalMapper.csar), the LIDAR data took precedence, to create a combined CSAR surface BB_Combine_FINAL_28Aug2013.csar), then exported the combined bathy and bathy LiDAR grid to an Esri ASCII grid (BB_Combine_wLIDAR_28Aug2013.asc). The original LiDAR GeoTIFFs were in Geographic NAD83 horizontal datum and NAVD88 vertical datum. They were reprojected and transformed to UTM Zone 19N horizontal datum during the import to CARIS BASE Editor CSAR format.

In ArcMap 10.1: Using ArcToolbox - conversion tools - to Raster - ASCII to Raster: input BB_Combine_wLIDAR_28Aug2013.asc, output D:\BuzzardsBay\Bathy_working\FINAL_GRID\temp, float Using ArcToolbox - Spatial Analyst Tools - Extraction - Extract by Mask: Clipped the grid "temp" by the shapefile BuzzBay_WaterOnly_shape.shp, output temp_clip Using ArcToolbox - Spatial Analyst Tools - Extraction - Extract by Attributes: Clipped the grid to "value < 0", output D:\BuzzardsBay\Bathy_working\FINAL_GRID\BB_NAVD88_10m

Using 3D Analyst, a hillshade was created using Surface Analysis - Hillshade. The azimuth was 315, the altitude was 45, and the z-factor was 2. The hillshade grid was converted to a TIFF by right-clicking on the grid in the table of contents and choosing "export data" and TIFF image format.

Edits to the metadata were made to fix any errors that MP v 2.9.32 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Empty fields were deleted. Links to the data were fixed. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.

Added keywords section with USGS persistent identifier as theme keyword.