A Time Source for a Data Acquisition System Designed for Phase Propagation Study of Magnetic Pulsations

Abstract

A time source for a data acquisition system was designed to use the fluxgate magnetometer for the measurement of long-distance phase propagation of magnetic pulsations at very low latitudes. The time source consists of a very low frequency (VLF) signal receiver, antenna, time code generator with crystal oscillator, and microcomputer chip. Omega navigation signals received by the VLF receiver are utilized for the time base. The computer-aided system can choose the Omega station with the greatest signal strength at the observation site and can decode the transmitted signals to utilize them as the time source of the internal clock. The prominent feature of this system is software-aided fully automatic operation at any location in the world. The overall accuracy of the clock is expected to be ±30 ms.