THE AUTOMATIC REMOTE GEOMAGNETIC OBSERVATORY SYSTEM (ARGOS) OPERATED IN THE UK BY THE BRITISH-GEOLOGICAL-SURVEY

ARGOS, an instrument and recording system for performing standard geomagnetic observatory functions at the three U.K. observatories, is described. Operations are controlled by a minicomputer at each observatory communicating by modem through the public telephone system to a central computer in Edinburgh. A fluxgate magnetometer provides 10-s samples of the variation field at + 1 nT resolution. These values are filtered to produce 1-min values (centred on the minute) which in turn are used to compute hourly mean values. These and other derivatives of the raw data are stored in the observatory computer and transmitted to Edinburgh daily by operator command, where they are transferred to a data file which can be accessed by users via the Joint Academic Network computer network (JANET). Observatory data are available to users by this means within 24 h and can be made available in near real time by special arrangement. ARGOS performs standardization measurements of the values of the field components remotely using a proton magnetometer employing standard techniques for absolute observations. Comparison of these Baseline Reference Measurements with manual absolute observations shows them to be acceptable for baseline adoption. In the first year of operation it has been established that ARGOS produces data which are of comparable quality to the classical standards expected from the U.K. observatories. Data loss has been less than 1%. Further automation of routine procedures (e.g. magnetogram plotting, editing, baseline adoption and the adjustment of minute values day by day) will be the focus of attention in the next 2 years. © 1990.