The DST group high-fidelity, multichannel oblique incidence ionosonde

Defence Science and Technology Group has developed a complete oblique incidence ionosonde system to enhance ionospheric monitoring capabilities in support of the Jindalee Operational Radar Network. The Digital Oblique Receiving System, and its counterpart, the Digital Oblique Transmitting System, feature a direct-digital, multichannel chirp-sounder design that allows flexible collection of high-resolution ionograms across many simultaneous paths, without compromising dynamic range. This paper outlines the hardware and software components of the Digital Oblique Receiving System/Digital Oblique Transmitting System, including the onboard signal processing that removes radio frequency interference and fits a parameterized electron density profile to the ionogram. Additional control and data management tools that have enabled the system to be effectively transitioned into routine operations are also described. The typical performance is illustrated through a selection of sample ionograms, highlighting the applications of Digital Oblique Receiving System/Digital Oblique Transmitting System to a wide variety of ionospheric studies, including those requiring Doppler and angle-of-arrival observations.