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USGS Open-File Report 2005-1027, An Operational Mean High Water Datum for Determination of Shoreline Position from Topographic Lidar Data

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Data Sets & Methods

List of Appendices

Appendix 1 (PDF Format): Sample of a bench mark datasheet obtained from the Center for Operational Oceanographic Products and Services (CO-OPS) Web site for Atlantic Beach, North Carolina. Note that the location of the station (Atlantic Ocean) is listed as part of the station name. The latitude and longitude of the station are given, and the tidal bench marks for the site are listed along with descriptions of their respective locations. Many of the bench marks are linked to National Geodetic Survey (NGS) datasheets by their Permanent IDentifier (PID#.) (See Appendix II (PDF Format) for a sample NGS datasheet).

Tidal datum and bench mark elevation information are listed on "page 4 of 5" of this Appendix. The Length of Series (the total number of months or years used in the computation of the tidal datums) is listed, along with the Time Period of station operation, Tidal Epoch, and Control Tide Station. Not all of the data collected during the Time Period is necessarily used in the calculation of the tidal datums (S. Lyles, NOAA, pers. comm). Tidal datum elevations and the elevation of the fixed vertical datum, NGVD 29, are referenced to Mean Lower Low Water. Tidal bench mark elevations above MLLW and MHW are also given. From

Appendix 2 (PDF Format): Sample of a National Geodetic Survey (NGS) datasheet linked to the Center for Operational Oceanographic Products and Services (CO-OPS) bench mark Web site. This datasheet is for the Atlantic Beach, North Carolina bench mark designated as 865 6590 B. The PID# linking the CO-OPS bench mark sheet to the NGS datasheet is AC7539. On this datasheet, the height of the bench mark (in both meters and feet) above the fixed vertical datum, NAVD 88, is given. Datasheets such as this one were used to calculate the height of MHW above NAVD 88 when the "Bench Mark Method" was used. From

Appendix 3 (PDF Format): Sample pages from the Center for Operational Oceanographic Products and Services (CO-OPS) tidal prediction Web site. Station name and location are listed along with the Mean Range, Spring Range, and Mean Tide Level. The "Predictions" links display the predicted tides (date, day, time, and height) for that location for each day for an entire year. From

Appendix 4 (PDF Format): Lidar tile information listed by state. Each state has a "00" tile which covers all coastal areas for that state. For example: Maryland has 2 tiles, plus the "state" tile. Md00 covers all of Maryland's coastal areas, while md01 and md02 divide md00 into smaller areas. Each tile also has a name, related to a geographic feature, city, or other landmark within it. A tile that is described as being "oversized" (nc10, la20, and ca18) or "undersized" (nc09), is one that does not have the standard dimensions of 0.25 degrees latitude/longitude on a side.

The boundaries for each tile are the eastern and western longitude boundaries and the southern and northern latitude boundaries. Longitude is given in 360 degree format, decimal degrees. To get "west" coordinates, subtract this value from 360. Example: 360 - 284.80 = -75.20 W. Latitude is North latitude in decimal degrees. The operational MHW elevations used to define the lidar shorelines are listed in the "Zref" column. If no Zref value is given, this indicates that no lidar shoreline will be derived within that tile, usually because the tile encompasses little or no open ocean, sandy coast. When two Zref values are listed for one tile, this indicates that Zref changes within a tile, usually at a natural coastal break, such as an inlet (see Table 5 (PDF Format) for a description). The lidar profiles within each tile are given as well. For tiles that have a Zref value, a lack of profile numbers indicates that the tile has not yet been processed for shoreline information under the National Assessment of Coastal Change Hazards Project.

Because Assateague Island is located off the coasts of both Maryland and Virginia, it is listed under both states. It is also a special study area and is therefore listed separately as well.

Appendix 5 (PDF Format): Figures showing lidar tiles for each state. On north/south trending coastlines along the East Coast, tile numbers increase from south to north within each state. On north/south trending coastlines along the West Coast and along the west coast of Florida, tile numbers increase from north to south. On east/west trending coastlines, tile numbers increase from west to east. The colored lines along the coastline show the regions where lidar shorelines will be derived. The states' "00" tiles are indicated by a dashed box while all other tiles are indicated by a solid box. These figures show the approximate boundaries for the tiles. The actual tile boundary limits are listed in Appendix IV (PDF Format) .

Appendix 6 (PDF Format): Figures showing lidar tiles and Mean High Water (MHW) Zones for each state. The colored lines along the shoreline show the extent of each MHW zone. Each zone has an operational MHW elevation assigned to it that is used to define the lidar shorelines derived within that zone. The operational MHW elevations for each zone (in meters above NAVD 88) are listed in the figure legends. Tables 5, 6, and 7 describe each zone in detail, while Figures 21-28 show the locations of the tide stations within each zone, the MHW elevations at each of the tide stations, and the operational MHW elevation for each zone.

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