DefinePK

Abstract

Ionosphere is the region in the atmosphere where ionization takes place. Its structure varies by altitude, time, and other solar or cosmic activities that affect the propagation of radio signals. Variations in the signal strengths of very low frequency signals as a result of ionospheric changes is a way to measure changes and disturbances in the ionosphere. Stanford University developed a VLF based monitor called SuperSID for monitoring changes within the ionosphere. In this project, an enhanced version of the SuperSID software was introduced, which includes a real-time visualization of signal strength versus time plot for the current day; and a plot function for a quiet day curve. The constructed microcomputer-based data acquisition system was validated using another SuperSID monitor from Stanford. Both are stationed in Manila, Philippines and are configured to monitor NWC (19.8 kHz) and NDT (22.2 kHz) transmitters. A statistical test was performed to validate the association between the monitors and resulted with an average correlation coefficient of 0.958 and 0.948 for NWC and NDT transmitters. Also, a successful characterization of solar flare and thunderstorm was done using an enhancement algorithm.