Browsing by Author "Janse van Vuuren, Lucas Jacobus"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- ItemDesign and test implementation of a global interconnected SQUID geomagnetometer network(Stellenbosch : Stellenbosch University, 2015-03) Janse van Vuuren, Lucas Jacobus; Fourie, Coenrad; Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.ENGLISH ABSTRACT: In 2012, a three-axis HTS-SQUID magnetometer project for geomagnetic measurements has been started at SANSA Space Science in Hermanus, South Africa. The goal of this project was to replicate a three-axis SQUID magnetometer for geomagnetic field measurements at LSBB at Rustrel, France. This is to allow better characterizing of faint, low frequency geomagnetic and ionospheric phenomena. To record the output signals of the SQUID magnetometers, a measurement system had to be developed. To utilise the full sensitivity of the SQUID magnetometers, the output signals have to be recorded with high accuracy. A high-speed and high-accuracy data acquisition system was installed and software was developed to record data from it. The software is capable of sending the recorded data to a web server as it is being recorded. Basic hardware control of the SQUID magnetometers has also been implemented from this data acquisition system, by monitoring conditions with its software. Timing accuracy is an important aspect of this system, in order to enable comparisons with measurements from LSBB and from different locations in the world. A GPS receiver was used to obtain the current UTC time accurately in order to timestamp measurements. A software method was devised for timestamping, to improve accuracy by triggering measurements directly from the GPS receiver. A hardware real-time clock between the GPS receiver and the rest of the system has been avoided using this method. For research purposes, this measurement data must be available on the internet for the lifetime of the system. A data server was set up and a large database of recorded data has been generated over two years of this project. Long term implementation issues have also been addressed. A web interface was developed for the data server to enable live viewing of the recorded data. This web interface also facilitates access to the raw measurements for public use. Analysis of phenomena in the recorded data has been performed by other students from Stellenbosch University.