Data Management Plan

These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise (SLR) and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: https://www.coast.noaa.gov/slr

This metadata record describes the Pago Pago Weather Service (PPG WSO) digital elevation model (DEM), which is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea Level Rise and Coastal Flooding Impacts Viewer described above. The DEMs created for this project were developed using the NOAA National Weather Service's Weather Forecast Office (WFO) boundaries. This DEM includes the best available lidar known to exist at the time of DEM creation that met project specifications for the Pago Pago WSO, which includes the following islands in American Samoa: Tutuila, Aunu'u, Ofu, Olosega, Tau, and Rose Atoll.

The DEM is derived from the following source.

1. 2012 American Samoa Lidar - acquired by NOAA and partners

Hydrographic breaklines were delineated from LiDAR intensity imagery generated from the LiDAR datasets. The final DEM is hydro flattened such that water elevations are less than or equal to -0.5 meters.

The DEM is referenced vertically to the American Samoa Vertical Datum of 2002 (ASVD02) with vertical units of meters and horizontally to the North American Datum of 1983 (PACP00). The resolution of the DEM is 3 meters. The spatial information section in this metadata may indicate NAD83(PA11) horizontally because the Inport metadata system doesn't know PACP00.

American Samoa

Process Steps:

• 2013-01-01 00:00:00 - The following datasets were used to develop the DEM: 1. 2012 American Samoa Lidar Hydrographic breaklines delineated from LiDAR intensity imagery generated from the LiDAR datasets. (Citation: 2012 American Samoa Lidar)
• 2013-01-01 00:00:00 - GeoCue software was used to develop LiDAR intensity imagery from the LiDAR. The raster resolution was 1ft or 0.3 m.
• 2013-01-01 00:00:00 - LiDAR intensity images were viewed in 2-D in ArcMap. Hydrographic features were collected as 2D breaklines.
• 2013-01-01 00:00:00 - Class 2, ground LiDAR points are exported from the LAS files into a file geodatabase (GDB) in multipoint format. Hydro breaklines are assigned an elevation of 0 meters and loaded into a geodatabase. An Esri Terrain is generated from these inputs.
• 2013-01-01 00:00:00 - The Esri terrain is reviewed in ArcMap and converted to a DEM in Erdas image file format with a cell size of 3 meters. The DEM is reviewed in Global Mapper for incorrect elevations and artifacts that are introduced from source inputs or during the raster creation process. Corrections are applied to the DEMs and reprocessed for review.
• 2013-01-01 00:00:00 - All DEMs are loaded into Global Mapper for the last review. During this last review, an analyst checks to ensure full, complete coverage, no issues along DEM boundaries, DEMs seamlessly edge-match, and that there are no remaining processing artifacts in the dataset. Once approved, DEMs are re-projected to the NAD83 geographic coordinate system.
• 2013-01-01 00:00:00 - Re-projected DEMs are further assessed for quality and consistency using Global Mapper. Fine-scale features, including bridges over narrow water bodies and small islands, are assessed for accuracy and edited accordingly. Once the DEMs are polished, they are re-projected to the Universal Transverse Mercator coordinate system.

Data is available online for bulk or custom downloads