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Short Citation:
National Geodetic Survey, 2024: Airborne Gravity: NGS' Gravity Data for AN08 (2016), https://www.fisheries.noaa.gov/inport/item/39705.

Item Identification

Title: Airborne Gravity: NGS' Gravity Data for AN08 (2016)
Short Name: GRAVD_AN08
Status: Completed
Publication Date: 2016-10
Abstract:

Airborne gravity data for Alaska collected in 2016 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D) project initiated by NOAA's National Geodetic Survey to collect and monitor gravity data suitable for the re-definition of the vertical datum for at least the United States and territories. The data is available at http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml in ASCII text format.

Purpose:

These data sets were collected and processed by NOAA's National Geodetic Survey (www.ngs.noaa.gov) as part of its GRAV-D effort to modernize the U.S. vertical datum. The purpose of these data is to provide accurate gravity data for geoid modeling for the U.S. and its territories. It was designed to provide medium wavelength gravity information (around 20-400 km) to connect satellite and ground gravity measurements.

Notes:

1260

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > ATMOSPHERE > ALTITUDE > GEOPOTENTIAL HEIGHT
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > MARINE GEOPHYSICS > MARINE GRAVITY FIELD
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > SOLID EARTH > GEODETICS > GEOID CHARACTERISTICS
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > SOLID EARTH > GRAVITY/GRAVITATIONAL FIELD
ISO 19115 Topic Category
geoscientificInformation
UNCONTROLLED
NASA/GCMD Data Center Keywords Data Center > Government Agencies-U.S. Federal Agencies > DOC/NOAA/NOS/NGS > National Geodetic Survey, National Ocean Service, NOAA, U.S. Department of Commerce
NASA/GCMD Data Center Keywords DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
NASA/GCMD Platform Keywords Platform > Aircraft > King Air 200T
NOS Data Explorer Topic Category Geodetic/Global Positioning
None airborne gravity
None datum
None ellipsoid height
None geodetic
None geoid
None geophysical
None GEOSS
None GGOS
None Global Earth Observation System of Systems
None Global Geodetic Observing system
None gravity
None height modernization
None National Spatial Reference System
None NAVD88
None North American Vertical Datum of 1988
None NSRS
None orthometric height
None spatial reference
None vertical

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALASKA
UNCONTROLLED
NASA/GCMD Location Keywords Location > Ocean > Chukchi Sea

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords
GPS RECEIVERS > GPS RECEIVERS
Global Change Master Directory (GCMD) Instrument Keywords
GRAVIMETERS
Global Change Master Directory (GCMD) Instrument Keywords
IMU > INERTIAL MEASUREMENT UNIT
Global Change Master Directory (GCMD) Instrument Keywords
LRGM > Lacoste-Romberg Gravity Meter

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
ENVISAT > Environmental Satellite
Global Change Master Directory (GCMD) Platform Keywords
ERS-1 > European Remote Sensing Satellite-1
Global Change Master Directory (GCMD) Platform Keywords
ERS-2 > European Remote Sensing Satellite-2
Global Change Master Directory (GCMD) Platform Keywords
GOCE > Gravity Field and Steady-State Ocean Circulation Explorer
Global Change Master Directory (GCMD) Platform Keywords
GPS > Global Positioning System Satellites
Global Change Master Directory (GCMD) Platform Keywords
GRACE > Gravity Recovery and Climate Experiment
Global Change Master Directory (GCMD) Platform Keywords
GROUND-BASED OBSERVATIONS > GROUND-BASED OBSERVATIONS
Global Change Master Directory (GCMD) Platform Keywords
JASON-1
Global Change Master Directory (GCMD) Platform Keywords
OSTM/JASON-2 > Joint Altimetry Satellite Oceanography Network - 2
Global Change Master Directory (GCMD) Platform Keywords
TOPEX/POSEIDON > Ocean Topography Experiment

Physical Location

Organization: National Geodetic Survey
City: Silver Spring
State/Province: MD

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Data Presentation Form: Table (digital)
Entity Attribute Overview:

The ASCII text file provides a single processed observation per row with the following elements comma separated: year, month, day, hour, minutes, seconds, latitude (dd), longitude (dd), ellipsoid height (m), full field gravity at altitude (mGals), full field EGM08 gravity at altitude (mGal)

Entity Attribute Detail Citation:

http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml

Distribution Liability:

While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

Support Roles

Data Steward

CC ID: 480488
Date Effective From: 2016-10
Date Effective To:
Contact (Organization): NGS Communications and Outreach Branch
Email Address: ngs.infocenter@noaa.gov
Phone: (301) 713-3242
Fax: (301) 713-4172

Distributor

CC ID: 480490
Date Effective From: 2016-10
Date Effective To:
Contact (Organization): NGS Communications and Outreach Branch
Email Address: ngs.infocenter@noaa.gov
Phone: (301) 713-3242
Fax: (301) 713-4172

Metadata Contact

CC ID: 480491
Date Effective From: 2016-10
Date Effective To:
Contact (Organization): NGS Communications and Outreach Branch
Email Address: ngs.infocenter@noaa.gov
Phone: (301) 713-3242
Fax: (301) 713-4172

Point of Contact

CC ID: 480489
Date Effective From: 2016-10
Date Effective To:
Contact (Organization): NGS Communications and Outreach Branch
Email Address: ngs.infocenter@noaa.gov
Phone: (301) 713-3242
Fax: (301) 713-4172

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 480494
W° Bound: -169.46
E° Bound: -158.29
N° Bound: 69.24
S° Bound: 64.6

Extent Group 1 / Time Frame 1

CC ID: 480493
Time Frame Type: Range
Start: 2016-05
End: 2016-07

Spatial Information

Spatial Representation

Representations Used

Vector: Yes

Vector Representation 1

CC ID: 586790
Curve Object Present?: Yes
Curve Object Count: 172203

Access Information

Security Class: Unclassified
Data Access Constraints:

None

Data Use Constraints:

Must read and fully comprehend the metadata prior to use, acknowledgment of the Originator when using the data set as a source, data should not be used beyond the limits of the source scale

Distribution Information

Distribution 1

CC ID: 480495
Download URL: http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml
Distributor:
Description:

Downloadable Data

File Type (Deprecated): ASCII
Distribution Format: Text (Unstructured)
Compression: Uncompressed

URLs

URL 1

CC ID: 480485
URL: http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml
URL Type:
Online Resource

URL 2

CC ID: 480486
URL: http://www.ngs.noaa.gov/GRAV-D/data_products.shtml
URL Type:
Online Resource

URL 3

CC ID: 480487
URL: http://www.ngs.noaa.gov/
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 480543
Activity Date/Time: 2016-10-04
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 480542
Activity Date/Time: 2017-04-05
Description:

Converted from FGDC Content Standard for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 586788
Activity Date/Time: 2017-09-13
Description:

Partial upload of Spatial Info section only.

Activity Log 4

CC ID: 598806
Activity Date/Time: 2017-11-01
Description:

Replaced entire Lineage section to populate new Source Contribution field.

Activity Log 5

CC ID: 716867
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Data Quality

Accuracy:

The absolute accuracy of airborne gravity is difficult to quantify. The following measures are indicators of data quality, but are not definitive measures. The cross over precision is 0.19 mGals, which is a combination of differences between cross track and data track and may not be indicative of data quality. Adjacent data lines have an average cross-correlation of 99.72%. Low correlation between adjacent lines may indicate either poor quality on one of the two lines or rapidly changing features. More detailed information can be found at http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml.

Horizontal Positional Accuracy:

GPS horizontal positions are good to 0.005 meters average standard deviation. More detailed information can be found at http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml.

Vertical Positional Accuracy:

GPS vertical positions are good to 0.008 meters average standard deviation. More detailed information can be found at http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml.

Completeness Report:

Due to the altitude, speed of data collection, and track spacing of 10 kilometers the resolution of these data are limited to 20 kilometers. More detailed information can be found at http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml.

Conceptual Consistency:

Data processing is fully automated and output file is computer generated. All lines are checked by an analyst and any errors in production are corrected. More detailed information can be found at http://www.ngs.noaa.gov/GRAV-D/data_an08.shtml.

Lineage

Sources

Gravity Data from Flight AK16-2

CC ID: 598807
Contact Name: NOAA's National Geodetic Survey
Extent Type: Range
Extent Start Date/Time: 2016-05
Extent End Date/Time: 2016-07
Source Contribution:

Airborne gravity survey, including data collection from airborne and ground GPS, IMUs, and gravimeters, that was included in this geographic block | Source Geospatial Form: tabular digital data | Type of Source Media: digital

Processed GPS Data from Flight AK16-2

CC ID: 598808
Contact Name: NOAA's National Geodetic Survey
Extent Type: Range
Extent Start Date/Time: 2016-05
Extent End Date/Time: 2016-07
Source Contribution:

Processed GPS data is created from tying kinematic GPS data from the plane to base stations on the ground and is used to process and tie gravity measurements | Type of Source Media: digital

Process Steps

Process Step 1

CC ID: 598809
Description:

GPS data processed using Inertial Explorer 8.5 | Source Produced: Processed GPS Data from Flight AK16-2

Process Date/Time: 2013-10-01 00:00:00
Source: Gravity Data from Flight AK16-2

Process Step 2

CC ID: 598810
Description:

Gravity data processed using NGS software Newton | Source Produced: Processed GPS Data from Flight AK16-2

Process Date/Time: 2013-10-01 00:00:00
Source: Gravity Data from Flight AK16-2

Catalog Details

Catalog Item ID: 39705
GUID: gov.noaa.nmfs.inport:39705
Metadata Record Created By: Tyler Christensen
Metadata Record Created: 2017-04-05 13:06+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-10-17 16:12+0000
Metadata Record Published: 2018-02-08
Owner Org: NGS
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2018-02-08
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2019-02-08