OahuW_shorelines - Shorelines of the western coastal region of Oahu, Hawaii, from Yokohama to Tracks Beach, used in shoreline change analysis.

Shoreline data were sought from local and national archives, libraries, and vendors in an effort to compile as many quality historical shorelines as possible for the region. T-sheets were requested from NOAA and received as scanned raster images. Processing date from 1998 to 2008.

Georeferenced T-sheets were obtained from the United States Department of Commerce, National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), National Geodetic Survey (NGS). T-sheets were rectified by NOAA on a Sun Microsystems(r) workstation using Environmental Systems Research Institute, Inc. (ESRI)(r) ArcInfo(r) version 7.2.1 software by placing at least 6 well-spaced ground control points (GCPs) on selected T-sheet graticules in geographic coordinates. Some T-sheets produced before 1930 required additional coordinate transformation information from NOAA to convert from the United States Standard Datum (USSD) to the North American Datum of 1927 (NAD27). In the Hawaiian Islands, the adoption of the NAD27 datum for mapping and the emergence of several unsupported local and island-specific datums have led to significant confusion among cartographers and surveyors. The datum transformation was applied to T-sheet graticule coordinates prior to rectification. Total Root Mean Square (RMS) error for the rectification process was maintained below 1 pixel, which is approximately 4 m at a scale of 1:20,000 and approximately 1.5 m at a scale of 1:10,000. Typically the resulting RMS was much lower than one pixel.
Geo-referenced T-sheets were loaded in ArcMap version 9.3. ArcMap was used to transform received Geographic Projected data into the Universal Transverse Mercator (UTM) projection with the North American Datum of 1983 (NAD83) datum for digitizing and vector analysis. A verification of the T-sheet shoreline was carried out where possible using control marks or physical shoreline features present on the T-sheet and a reliable current image database. Where verification failed, T-sheets were re-rectified in PCI Geomatics Orthoengine version 10.1 software using ground control points on existent control stations and identifiable shoreline features. In all cases, shoreline feature verification produced a higher quality data product.
Many T-sheet products used in this study were re-rectified in PCI to correct significant errors associated with incorrect projection datum definitions. Such errors would have otherwise rendered the sheets unusable. T-sheets are georeferenced using polynomial mathematical models in PCI with RMS errors < 4 m. Rectification of T-sheets is also verified by overlaying them on aerial photomosaics to compare their fit to rocky shoreline and other unchanged geological features. Processing date from 2006 to 2009.

New aerial photographs were taken of the Kauai, Oahu, and Kihei (Maui) shoreline between 2005 and 2008 by Air Flight Services, Inc. Aircraft position (global positioning system locations) and orientation data (e.g., altitude, pitch, roll, and yaw) were recorded by an on-board positional orientation system (POS). The recent images are orthorectified and mosaicked in PCI Geomatica Orthoengine software using polynomial models incorporating POS data and high resolution (5m -horizontal, submeter vertical) DEMs to reduce displacements caused by lens distortion, Earth curvature, refraction, camera tilt, and terrain relief; usually achieving Root Mean Square (RMS) positional error < 2 m.
Earlier aerial photographs are orthorectified and mosaicked in PCI Geomatica Orthoengine using 2005-2008 and 1998 (west and north Maui) aerial orthophoto mosaics as master images (for collecting Ground Control Points (GCPs)) and high resolution (5m -horizontal, submeter vertical) DEMs to reduce displacements caused by lens distortion, Earth curvature, refraction, camera tilt, and terrain relief; usually achieving Root Mean Square (RMS) positional error < 2 m. Processing date from 2005 to 2008.

Historical shorelines are digitized from NOAA NOS topographic maps (T-sheets) and 0.5 m orthorectified aerial photo mosaics in PCI Geomatica Focus Software. Quality assessments were performed and shorelines were edited to remove any overlap between adjacent shorelines. No edge matching between adjacent shorelines was attempted.
Shoreline layers were saved from .pix (PCI Geomatics geographic data format) to shapefile (.shp) to allow for analysis in ESRI ArcGIS software using Digital Shoreline Analysis System (DSAS). Shoreline layers from all sources were merged to produce a single shoreline shapefile for the coastal region. The final shoreline shapefile was coded with 4 attribute fields (ID, Shape, Date, and Accuracy) required for the DSAS, which was used to calculate shoreline change rates. The attributes reflect the source of the data and the original survey date. Processing date from 2008 to 2010.

The appended shoreline files were imported into a personal geodatabase in ArcCatalog v9.3 by right-clicking on the geodatabase > Import feature class for shoreline file for use with the Digital Shoreline Analysis System (DSAS) v4.2 software to perform rate calculations.
This and all following process steps performed by Bradley M. Romine, University of Hawaii Coastal Geology Group.

The shoreline feature class was exported from the personal geodatabase back to a shapefile in ArcCatalog v9.3 by right-clicking on the shoreline file > Export > To Shapefile (single) for publication purposes.

The data were projected in ArcToolbox v9.3 > Data Management Tools > Projections and Transformations > Feature > Project. Parameters: input projection = UTM zone 4N (NAD83); output projection = geographic coordinates (WGS84); transformation = 3 (Hawaii).

Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.

Added keywords from Coastal and Marine Ecological Classification Standard (CMECS) to metadata.

Edits to the metadata were made to fix any errors that MP v 2.9.46 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.). Added a data landing page link as the first link in the identification section. Removed LIDAR bounding coordinates - an artifact of Esri and MP processing. Fixed date format in process steps. Minor fixes to attribute information. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. Added additional information to a cross-reference and fixed the online link. Attempted to modify http to https where appropriate. 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.