Introduction to our New System: Magnetometer for Wide Frequency Range
T. Oowada, T. Tokumoto, Y. Yamada, M. Ozima, N. Kumasaka, M. Yokoyama, M. Sugawara, K. Koike, and Y. Shimizu
Abstract
During 1995 and 1996, Kakioka Magnetic Observatory developed a new measurement system of magnetometer for wide frequency range at both two branches, Memambetsu and Kanoya and we just started to operate them. By the use of one single highly sensitive fluxgate-magnetometer as a sensor which is applicable for low-frequency to high-frequency ranges, we can obtain digital values at every 0.1-second and 1-second. Data collections are carried out using a personal computor basically. At Kakioka, we reconstructed our high-sensitivity fluxgate-magnetometer which has been operated for 1-second value measurement since 1990, and added a data collection unit in such a way that we can obtain 0.1-second values as well. We can draw a magnetogram-like picture of which time- response is better than that by so-called variometer by plotting these 1-second values of the three components. Similarly, we can detect rapid variations such as magnetic pulsations easily and precisely by plotting these 0.1-second values of the three components. Accordingly, we terminated both the variometer measurements and the observation with induction coils at three observatories. These digital values of 0.1-second and 1-second are expected to be utilized in every field of geomagnetism.
Received 26 December 1997; Revised 20 February 1998
