Monitoring of the Earth's magnetic field for research and practical applications.
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.