US Historic Declination CalculatorAlternate Views: Get Data, FAQ, ISO Rubric, DOI Rubric, CSW, HTML, Components, XML
US Historic Declination Calculator
browse graphicThis programs derives a table of secular change in magnetic declination for a specified point in the conterminous United States. It utilizes the USD polynomial and the IGRF spherical harmonic models. Declination is calculated using the current World Magnetic Model (WMM) or International Geomagnetic Reference Field (IGRF) model. While results are typically accurate to 30 minutes of arc, users should be aware that several environmental factors can cause disturbances in the magnetic field.

Get the Data
AccessFormat(s)Distributor(s) / Contact InfoInstructions / Constraints
HTML Format
Format version: 1
Format specification: The Declination Calculator creates an HTML pop-up window which superimposes a compass rose, indicating the declination, onto the location queried and reports the annual change in declination.
XML Format
Format version: 1
Format specification: The Declination Calculator creates an XML file which reports the location and date queried as well as the declination and the annual change in declination in decimal minutes per year.
CSV Format
Format version: 1
Format specification: The Declination Calculator creates an Comma Seperated Variable (CSV) file which reports the location and date queried as well as the declination and the annual change in declination in decimal minutes per year.
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Fees
None

Use Limitation
Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.

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