Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. 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.

The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity, easterly intensity, vertical intensity) and the annual change for each. Each calculation is for a specific location, elevation and date or range of dates. The calculated result can be obtained from two separate geomagnetic models, the IGRF11 or the WMM2010. 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.

The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V-MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field model for epoch 2010.0, and a linear predictive secular variation meodel for 2010.0-2015.0.

The study of magnetism is one of the oldest of the geophysical sciences. It is unique among the sciences in that ancient records of the geomagnetic field are preserved in rocks and changes in the field can be traced through time. To assist the scientist studying the Earth's ancient magnetization, the National Geophysical Data Center (NGDC) has available the following data of paleopole positions and paleomagnetic directions. The Global PaleoMagnetic Directions and Poles Data Base (GPMDB) Version 3.1 revised May 1995. This data base, established by M. McElhinny and J. Lock under the authority of the International Association of Geomagnetism and Aeronomy (IAGA), contains all published data up to 1995 and has references linked to data results. The data base was developed under MicroSoft Access 2.0 and includes following information: AUTHORS, Table of authors, linked to REFERENCE and ROCKUNIT The REFERENCE, Table of books, journals etc. from which data were extracted ROCKUNIT, position, geology, age, and structure information PMAGRESULT, results, reversal test, lab test, tilt corrections and comments ALTRESULT, pole position and statistics where derived from VGP FIELDTESTS, type of field tests done and results with commentary Several other related data bases are available including Paleointensity (PALIN), Polarity Transitions (TRANS), and Secular Variation (SECVR).

The High Definition Geomagnetic Model (HDGM) is a global, high resolution model of the Earth's geomagnetic main and crustal field, providing magnetic field values (total field, dip, and declination) at any point above or below the Earth's surface. Well planners can use HDGM to compute magnetic reference values at any point, as well as easily integrate HDGM into their directional drilling software. HDGM is updated annually to correctly model secular changes in the geomagnetic field. The US National Oceanic and Atmospheric Administration (NOAA), in partnership with the directional drilling industry and the University of Colorado have developed a real-time component for NOAA's High Definition Geomagnetic Model. HDGM-RT improves the HDGM by accurately modeling the magnetic fields originating in the Earth's magnetosphere in real-time using a combination of solar-wind observing satellites situated between Earth and sun and a chain of geomagnetic observatories on the Earth's surface. The model also includes an ionospheric field model calculated from a combination of observatory and Swarm satellite data in order to represent the daily variations in the ionosphere. The addition of HDGM RT can save rig-time and reduce the drilling cost by enabling improved drill string interference correction during adverse space weather conditions.

The High Definition Geomagnetic Model (HDGM) is a global, high resolution model of the Earth's geomagnetic main and crustal field, providing magnetic field values (total field, dip, and declination) at any point above or below the Earth's surface. Well planners can use HDGM to compute magnetic reference values at any point, as well as easily integrate HDGM into their directional drilling software. HDGM is updated annually to correctly model secular changes in the geomagnetic field. The US National Oceanic and Atmospheric Administration (NOAA), in partnership with the directional drilling industry and the University of Colorado have developed a real-time component for NOAA's High Definition Geomagnetic Model. HDGM-RT improves the HDGM by accurately modeling the magnetic fields originating in the Earth's magnetosphere in real-time using a combination of solar-wind observing satellites situated between Earth and sun and a chain of geomagnetic observatories on the Earth's surface. The model also includes an ionospheric field model calculated from a combination of observatory and Swarm satellite data in order to represent the daily variations in the ionosphere. The addition of HDGM RT can save rig-time and reduce the drilling cost by enabling improved drill string interference correction during adverse space weather conditions.

The High Definition Geomagnetic Model (HDGM) is a global, high resolution model of the Earth's geomagnetic main and crustal field, providing magnetic field values (total field, dip, and declination) at any point above or below the Earth's surface. Well planners can use HDGM to compute magnetic reference values at any point, as well as easily integrate HDGM into their directional drilling software. HDGM is updated annually to correctly model secular changes in the geomagnetic field. The US National Oceanic and Atmospheric Administration (NOAA), in partnership with the directional drilling industry and the University of Colorado have developed a real-time component for NOAA's High Definition Geomagnetic Model. HDGM-RT improves the HDGM by accurately modeling the magnetic fields originating in the Earth's magnetosphere in real-time using a combination of solar-wind observing satellites situated between Earth and sun and a chain of geomagnetic observatories on the Earth's surface. The model also includes an ionospheric field model calculated from a combination of observatory and Swarm satellite data in order to represent the daily variations in the ionosphere. The addition of HDGM RT can save rig-time and reduce the drilling cost by enabling improved drill string interference correction during adverse space weather conditions.

The High Definition Geomagnetic Model (HDGM) is a global, high resolution model of the Earth's geomagnetic main and crustal field, providing magnetic field values (total field, dip, and declination) at any point above or below the Earth's surface. Well planners can use HDGM to compute magnetic reference values at any point, as well as easily integrate HDGM into their directional drilling software. HDGM is updated annually to correctly model secular changes in the geomagnetic field. The US National Oceanic and Atmospheric Administration (NOAA), in partnership with the directional drilling industry and the University of Colorado have developed a real-time component for NOAA's High Definition Geomagnetic Model. HDGM-RT improves the HDGM by accurately modeling the magnetic fields originating in the Earth's magnetosphere in real-time using a combination of solar-wind observing satellites situated between Earth and sun and a chain of geomagnetic observatories on the Earth's surface. The model also includes an ionospheric field model calculated from a combination of observatory and Swarm satellite data in order to represent the daily variations in the ionosphere. The addition of HDGM RT can save rig-time and reduce the drilling cost by enabling improved drill string interference correction during adverse space weather conditions.

These data are vector and scalar component values of the Earth's magnetic field for 2004 recorded at the Boulder Magnetic Observatory in Colorado. Vector values are measured using 3 mutually orthogonal fluxgate magnetometer sensors. The scalar value of the total magnetic field is recorded with a proton precession magnetometer. All values are calibrated with measurements of the absolute value of the geomagnetic field using a DI-Flux magnetometer. The data are numerically filtered to prevent aliasing, and quality controlled during processing. Longer period values of the field, including hourly, daily, monthly, and annual means are derived from the 1-minute data.

The High Definition Geomagnetic Model (HDGM) is a global, high resolution model of the Earth's geomagnetic main and crustal field, providing magnetic field values (total field, dip, and declination) at any point above or below the Earth's surface. Well planners can use HDGM to compute magnetic reference values at any point, as well as easily integrate HDGM into their directional drilling software. HDGM is updated annually to correctly model secular changes in the geomagnetic field. The US National Oceanic and Atmospheric Administration (NOAA), in partnership with the directional drilling industry and the University of Colorado have developed a real-time component for NOAA's High Definition Geomagnetic Model. HDGM-RT improves the HDGM by accurately modeling the magnetic fields originating in the Earth's magnetosphere in real-time using a combination of solar-wind observing satellites situated between Earth and sun and a chain of geomagnetic observatories on the Earth's surface. The model also includes an ionospheric field model calculated from a combination of observatory and Swarm satellite data in order to represent the daily variations in the ionosphere. The addition of HDGM RT can save rig-time and reduce the drilling cost by enabling improved drill string interference correction during adverse space weather conditions.