Great Bay, NH (N130) Bathymetric Digital Elevation Model (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA

Metadata Updated: February 27, 2019

Bathymetry for Great Bay was derived from six surveys containing 30,640 soundings. One older, less accurate, overlapping survey was omitted before tinning the data. The average separation between soundings was 39 meters. There was a survey in the southeast that dated from 1950. The other five surveys dated from 1953 or 1954. The total range of soundings was 3.4 meters to -24.7 meters at mean low water. Mean high water values between 2.1 and 2.7 meters were assigned to the shoreline. Ten points were found that were not consistent with the surrounding data. These were removed prior to tinning. DEM grid values outside the shoreline (on land) were assigned null values (-32676). Great Bay has five 7.5 minute DEMs and a single one degree DEM. The 1 degree DEMs were generated from the higher resolution 7.5 minute DEMs which covered the estuary. A Digital Elevation Model (DEM) contains a series of elevations ordered from south to north with the order of the columns from west to east. The DEM is formatted as one ASCII header record (A- record), followed by a series of profile records (B- records) each of which include a short B-record header followed by a series of ASCII integer elevations (typically in units of 1 centimeter) per each profile. The last physical record of the DEM is an accuracy record (C-record). The 7.5-minute DEM (30- by 30-m data spacing) is cast on the Universal Transverse Mercator (UTM) projection. It provides coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as a standard USGS 7.5-minute quadrangle but the DEM contains over edge data. Coverage is available for many estuaries of the contiguous United States but is not complete.

Access & Use Information

License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Date June 12, 2018
Metadata Created Date February 27, 2019
Metadata Updated Date February 27, 2019
Reference Date(s) June 6, 1998 (publication)
Frequency Of Update irregular

Metadata Source

Harvested from NOAA CSW Harvest Source

Additional Metadata

Resource Type Dataset
Metadata Date June 12, 2018
Metadata Created Date February 27, 2019
Metadata Updated Date February 27, 2019
Reference Date(s) June 6, 1998 (publication)
Responsible Party DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce (Point of Contact)
Contact Email
Access Constraints Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Bbox East Long -70.687632
Bbox North Lat 43.190601
Bbox South Lat 43.039643
Bbox West Long -70.932275
Coupled Resource
Frequency Of Update irregular
Guid gov.noaa.ngdc.mgg.dem:great_bay_n130_30m
Harvest Object Id 2a507620-fa27-4c07-aa45-00b94ce9b9c7
Harvest Source Id 2aed8e29-fc5b-4cde-aa66-fb1118fd705e
Harvest Source Title NOAA CSW Harvest Source
Licence Not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For navigation, please refer to the NOS nautical chart series., Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.
Metadata Language
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System urn:ogc:def:crs:EPSG::5866
Spatial Harvester True
Temporal Extent Begin 1950-01-01
Temporal Extent End 1954-01-01

Didn't find what you're looking for? Suggest a dataset here.