An Introduction to the AFGL Magnetometer Network,
Abstract
The seven-station magnetometer network of the Air Force Geophysics Laboratory is currently in continuous operation. Five data-collection stations (Newport, WA, Rapid City, SD, Camp Douglas, WI, Mount Clemens, MI, and Sudbury, MA) form a 3800-km east-west chain at 55 degrees N corrected geomagnetic latitude. Two others (Lompoc, CA, and Tampa, FL) are separated by 3800 km at 40 degrees N corrected geomagnetic latitude. The principal instruments, identical at all stations, include a three-component induction-coil magnetometer to measure its time derivative. Sensitivities are about 0.1 gamma and 0.001 gamma-Hz, and sampling frequencies are one and five samples per second, respectively. The data-collection stations are not manned; measurements are made and processed automatically by microprocessor-based equipment at each station. Stations are synchronized and controlled remotely from the data-acquisition station at AFGL in Massachusetts. Outbound control and inbound data-return signals are transmitted on dedicated commercial voice-grade phone lines. Forward-error-correction techniques are used to assure accurate data transmissions. Operation is fulltime and continuous except for interruptions occasioned by malfunctions of the equipment or communications circuits. Data from all seven stations are processed and archived in near-real time by a dedicated minicomputer; values of the field and its time derivative are available within twenty seconds of the sampling time. Examples of the output data are presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1979
- Accession Number
- ADA068979
Entities
People
- Charles W. Tsacoyeanes
- David J. Knecht
- Robert O. Hutchinson
Organizations
- Air Force Research Laboratory