Simple Minimalistic Offline Plotting of CADI Data Files

Abstract

A critical element in any observational program is to remotely monitor instrument health and performance. Simple real-time plots provide this type of information and in addition they contain valuable space weather information for nowcasting and acquisition of situational awareness. Several software packages exist for plotting and scaling (analysis) of ionospheric soundings [1,2] using the Canadian Advanced Digital Ionosondes (CADIs) [3]. However, a simple method, not entailing installation of a full analysis package, for generating ionograms offline, or for near real-time displays generated on central server, is not easy to locate. Using information in the CADI documentation [4] combined with that found in analysis-package source-code [specifically 2], we have constructed a minimal Python package that takes a standard CADI output file [4] and generates (for example) a corresponding ionogram as a .png file. Moreover, written in Python, no licensing is required. In addition to plotting of individual classic ionograms, we offer plotting in the form of frequency profiles versus time and virtual height – essentially stacked ionograms with colour-coding indicating critical frequency, although not distinguishing between O and X modes. This displays the temporal development of ionospheric features, such as persistence and diurnal variation. Operating on an entire directory, the program can both display historical data and display continually updating files so as to show results in near real-time.