HR: 0800h
AN: SM21A-0358    [Abstracts]
TI: Progress on Low-Cost Pulse-Counting Magnetometers for Geomagnetic Studies
AU: * Connors, M
EM: martinc@athabascau.ca
AF: Athabasca University, 1 University Drive, Athabasca, AB T9S 3A3 Canada
AB: In keeping with the philosophy that "what the world needs now is a good $500 magnetometer", we have done further development and testing on what is now a relatively stable new design of triaxial magnetometer. With one sensor per axis we routinely detect variations of less than 1 nT with one-second sampling. Timing is derived from a GPS heartbeat pulse. Experimentation showed that designs with two sensors per axis produced more problems than they solved. Ground burial has been shown to be important due to the thermal sensitivity of the devices used. In addition, accurate calibration requires measurement of small temperature changes. A thermistor-based circuit which produces pulses whose frequency is related to temperature, but with a high frequency allowing accurate counting and thus detection of very small temperature changes, allows such calibration without any change in the basic design. The design itself is based on PIC microcontrollers, now commonly used. The viability of the intent to make a network of these inexpensive magnetometers in the Alberta (Canada) auroral zone has been demonstrated by a subauroral network of two-axis online (www.sam-europe.de) instruments run in Germany by amateurs. It is suggested that the limiting factor in deployment of such low-cost magnetometers should be connectivity, which is improving rapidly. Thus high temporal and spatial resolution magnetic studies, particularly in the auroral zone, will be enabled by these instruments.
DE: 2794 Instruments and techniques
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005