Several regions are represented in this unique collection of earth surface measurements of magnetic field parameters and their related anomalies. The DNAG Magnetics "Super grid" of Magnetic Anomaly Map of North America was created from the four "Original" DNAG Magnetic data sets distributed by The Committee for the Magnetic Anomaly Map of North America, 1987. This development of a super grid involved an extensive task of matching original quadrant information and eliminating overlap. The resulting grid, with x and y step intervals of 2.0 kilometers yields a grid with dimensions (4451 x 4273) containing 19,019,123 values. This process can be thought of as "stitching the grids." The data in this grid are in a Spherical Transverse Mercator projection, the kilometer coordinates of which can be recovered from the indices of a grid point. The Ministry of Geology of the USSR published a mosaic series of 18 maps in 1974, at a scale of 1:2,500,000 showing the residual magnetic intensity over the land mass of the USSR. Much of the source material originated from data collected between 1949-1962, during which time the entire territory of the USSR was surveyed using aerial magnetic survey techniques. These surveys wereadjusted based on many methods including secular variation linked to magnetic observatories. Anomalies were computed with reference to a normal field map for 1964-65 constructed from equally accurate total field measurements along control network strips. Digitization was accomplished in 1982 by the U.S. Naval Oceanographic Office. The "BRIGGS cubic spline" method was used to compute grid values. A one-minute grid was created by properly matching the boundaries of the digitized sub-sections. The units of the original map aremilli-Oersteds and the units of the resulting digital grid are milli-Oersted/100. Corrections to the digital contour file were made by Conoco Inc.in 1993. New Grid files at 2.5 Km and 5.0 Km spacing were created and re-archived by NGDC. These data are available on CD-ROM. World Data Center-A (WDC-A) for Solid Earth Geophysics presently holds Grid data from many U.S. and other regions. These data were contributed by: USGS, MINN G.S. and other Worldwide organizations. Grid intervals vary but are as fine as 213.36m for the NGS Super Grid of the state of Minnesota. Other grids were recreated indigital form from previously published maps and charts. The bulk of these grid data files were contributed to NGDC after 1985. A detailed list of the specific regions is available upon request.

The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) maintains an active database of worldwide geomagnetic observatory data to further the understanding of Earth magnetism and the Sun-Earth environment.Historically, magnetic observatories were established to monitor the secular change (variation), of the Earth's magnetic field, and this remains one of their most important functions. This generally involves absolute measurements sufficient in number to monitor instrumental drift and to produce annual means. Over 70 countries operate more than 200 observatories worldwide. The magnetic observatory data are crucial to the studies of secular change, investigations into the Earth's interior, navigation, communication, and to global modeling efforts. In addition to the continuously operating magnetic observatories, many countries make measurements at temporary magnetic stations (known as repeat stations), over a period of days every 5 - 10 years.The Earth's magnetic field is described by seven parameters. These are declination (D), inclination (I), horizontal intensity (H), vertical intensity (Z), total intensity (F) and the north (X) and east (Y) components of the horizontal intensity. By convention, declination is considered positive when measured east of north, inclination and vertical intensity positive down, X positive north, and Y positive east. The magnetic field observed on Earth is constantly changing.

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.

Three orthogonal flux-gate magnetometer elements, (spinning twin fluxgate magnetometer prior to GOES-8) provide magnetic field measurements in three mutually perpendicular components: HP, HE and HN. HP is perpendicular to the satellite's orbital plane. HE lies parallel to the satellite-Earth center line and points earthward. HN is perpendicular to both HP and HE, and points westward for GOES-4 and earlier satellites, and eastward for later spacecraft. The Synchronous Meteorological Satellites (SMS-1 and SMS-2) and the Geostationary Operational Environmental Satellites (GOES-1, GOES-2, etc.) all carry on board the Space Environment Monitor (SEM) instrument subsystem. The SEM has provided magnetometer, energetic particle, and soft X-ray data continuously since July 1974. Geosynchronous satellites have an unobstructed view of the sun for all but the few dozen hours per year when the Earth eclipses the sun. You can identify these intervals as gaps in the X-ray data near satellite local midnight in March-April, and September-October. The volume of these data makes it impossible to issue a guarantee as to the quality of each and every data point. Users should be suspicious of 'spikes' in the data and attempt to correlate them with other sources before assuming that they represent the space environment. The time of these observations has not been corrected for the down-link and preprocessing delay which is within 1 - 5 seconds.

Project Magnet data include low altitude, high density individual track line surveys, high altitude vector data and regional magnetic anomaly grids.

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Report on the status of world wide geomagnetic observatories

Geomagnetic variation data with 2.5 minute resolution

Geomagnetic Hourly Averages from world wide observatories

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.