This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Each geodetic control station in this dataset has either a precise Latitude/Longitude used for horizontal control or a precise Orthometric Height used for vertical control, or both.The National Geodetic Survey (NGS) serves as the Nation's depository for geodetic data. The NGS distributes geodetic data worldwide to a variety of users. These geodetic data include the final results of geodetic surveys, software programs to format, compute, verify, and adjust original survey observations or to convert values from one geodetic datum to another, and publications that describe how to obtain and use Geodetic Data products and services.

This 2' geoid height grid for the Principal Hawaiian Islands is distributed as a GEOID96 model. The computation used 61,000 terrestrial and marine gravity data held in the National Geodetic Survey gravity data base in July 1996. These data were augmented by gravity data contributions from NGA (former National Imagery and Mapping Agency (former Defence Mapping Agency)). By means of a Fast Fourier Transform (FFT) technique, high frequency corrections were made to an underlying EGM96 geopotential model through a remove, compute, and restore process. The gravity values are based on the International Gravity Standardization Net 1971 (IGSN71). The geoid heights are referred to the Geodetic Reference System 1980 (GRS80) ellipsoid. Unlike the grid for the conterminous United States, this GEOID96 grid does not incorporate GPS on leveled benchmarks. This model is a gravimetric geoid in a geocentric, ITRF94(1996.0) reference frame. It is necessary to subtract 12.0 cm from these values to obtain the geoid undulation between the best-fit global geopotential surface and the GRS80 ellipsoid (both expressed in a tide free system). Additional information is available at: http://www.ngs.noaa.gov/GEOID/geoid.html We are particularly grateful to NGA (former National Imagery and Mapping Agency) for their assistance and their data contributions.

In Gauss' words, the geoid is "the mathematical figure of the Earth". This figure is an equipotential surface coincident with the idealized mean sea surface. The geoid can be computed from the geodetic boundary value problems that use gravity data as its boundary value. A geoid model computed using gravity data is called gravimetric geoid. On the other hand, geoid height at bench marks can also be computed using data of the spirit leveling and the Global Positioning System (GPS). A geoid model that fixed to the GPS/leveling data is called hybrid geoid. Both geoid models can serve as the zero-height-surface of a country's height system by selection. To satisfy this need, National Geodetic Survey has published a series of geoid models (http://geodesy.noaa.gov/GEOID). The latest models are USGG2012 and GEOID12B, both are at 1 arc-second grids over the territory of the United States.

In Gauss' words, the geoid is "the mathematical figure of the Earth". This figure is an equipotential surface coincident with the idealized mean sea surface. The geoid can be computed from the geodetic boundary value problems that use gravity data as its boundary value. A geoid model computed using gravity data is called a gravimetric geoid. On the other hand, geoid height at bench marks can also be computed using data from spirit leveling and the Global Positioning System (GPS). A geoid model that is fixed to the GPS/leveling data is called a hybrid geoid. Both geoid models can serve as the zero-height-surface of a country's height system by selection. To satisfy this need, National Geodetic Survey has published a series of geoid models (https://geodesy.noaa.gov/GEOID). The vast majority of navigation and positioning applications utilize a hybrid geoid model with the latest model being GEOID18 for CONUS and Puerto Rico/U.S. Virgin Islands and GEOID12B for all other states and territories of the United States. The corresponding gravimetric geoid for these regions is xGEOID19B and USGG2012, respectively. All models are provided at 1 arc-minute resolution.

From August 15- September 2, 2021, NOAA Ocean Exploration conducted mapping operations on the Blake Plateau within U.S. waters, aiding in closing the gaps within this region. This cruise consisted of a strategic transit from Newport, Rhode Island to the primary working grounds off of the U.S Southeast, aimed at collecting data over previously mapped and potentially new seeps along the edge of the continental shelf. EX-21-05 collected 13,054 square kilometers of bathymetry and associated water column data, 12,989 square kilometers of which were within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m. The cruise concluded in Port Canaveral, FL on September 2, 2021. The exploratory mapping operations conducted during this cruise will provide initial characterization of the region, as well as data to support further exploration with remotely operated vehicles planned for EX-21-07.

This 2' geoid height grid for Puerto Rico and the Virgin Islands is distributed as a GEOID96 model. The computation used 26,000 terrestrial and marine gravity data held in the National Geodetic Survey gravity data base in July 1996 These data were augmented by gravity data contributions from NGA (former National Imagery and Mapping Agency (former Defence Mapping Agency)). By means of a Fast Fourier Transform (FFT) technique, high frequency corrections were made to an underlying EGM96 geopotential model through a remove, compute, and restore process. The gravity values are based on the International Gravity Standardization Net 1971 (IGSN71). The geoid heights are referred to the Geodetic Reference System 1980 (GRS80) ellipsoid. Unlike the grid for the conterminous United States, this GEOID96 grid does not incorporate GPS on leveled benchmarks. This model is a gravimetric geoid in a geocentric, ITRF94(1996.0) reference frame. It is necessary to subtract 12.0 cm from these values to obtain the geoid undulation between the best-fit global geopotential surface and the GRS80 ellipsoid (both expressed in a tide free system). Additional information is available at: http://www.ngs.noaa.gov/GEOID/geoid.htmlWe are particularly grateful to NGA (former National Imagery and Mapping Agency) for their assistance and their data contributions.

From September 5 - September 28, 2021, NOAA Ocean Exploration conducted mapping operations on the Blake Plateau within U.S. waters, aiding in closing the gaps within this region. The second of two cruises focused on mapping this region, EX-21-06 collected 25,800 square kilometers of bathymetry and associated water column data, 25,790 square kilometers of which were within the U.S. Exclusive Economic Zone and Territorial Sea deeper than 200 m. The exploratory mapping operations conducted during this cruise will provide initial characterization of the region, as well as data to support further exploration with remotely operated vehicles planned for EX-21-07.

GEOSAT DATA: Gridded Gravity Anomalies for the Southern Ocean

The Oahu, Hawaii Elevation Data Task Order involves collecting and delivering topographic elevation point data derived from multiple return light detection and ranging (LiDAR) measurements on the island of Oahu in Hawaii. The Statement of Work (SOW) for the area covering the northern 2/3 of Oahu was developed by the National Oceanic and Atmospheric Administration's (NOAA) Office for Coastal Management. A separate but related task order was issued by the USGS National Geospatial Technical Operations Center (NGTOC), under their Geospatial Products and Services Contract (GPSC), to leverage the same resources committed to the NOAA LiDAR project for the acquisition of LiDAR data in the southern 1/3 portion of Oahu. The combined task orders yielded one study area covering the entire island of Oahu. The data collected for the island of Oahu will exhibit Hydro Flattened DEMs for inclusion into the NED. The purpose of the data is for use in coastal management decision making, including applications such as flood plain mapping and water rights management. The point density for this data set was specified in the SOW at 1.15 pts/m2. The NOAA Office for Coastal Management tested the NPS (nominal pulse spacing) for this data set in April 2015. The NPS was determined to be 0.84 m. The data used in the NPS determination were the first returns of classes 1,2,9, and 10.

Hourly Precipitation Data (HPD) is digital data set DSI-3240, archived at the National Climatic Data Center (NCDC). The primary source of data for this file is approximately 5,500 US National Weather Service (NWS), Federal Aviation Administration (FAA), and cooperative observer stations in the United States of America, Puerto Rico, the US Virgin Islands, and various Pacific Islands. The earliest data dates vary considerably by state and region: Maine, Pennsylvania, and Texas have data since 1900. The western Pacific region that includes Guam, American Samoa, Marshall Islands, Micronesia, and Palau have data since 1978. Other states and regions have earliest dates between those extremes. The latest data in all states and regions is from the present day. The major parameter in DSI-3240 is precipitation amounts, which are measurements of hourly or daily precipitation accumulation. Accumulation was for longer periods of time if for any reason the rain gauge was out of service or no observer was present. DSI 3240_01 contains data grouped by state; DSI 3240_02 contains data grouped by year.