Despite starting nearly 100 kilometers above the surface of the Earth, the ionosphere plays an active role in our day-to-day lives affecting High-Frequency (HF) Radio propagation. International air traffic controllers, oceanographers using surface wave radars, the space launch community, and many others are all affected by electron density distribution in the ionosphere. The ionosphere lets you hear distant AM radio stations in your car but it can also affect the quality of long-range air traffic control communications.
Modeling the impacts of the ionosphere on HF Radio can be a significant challenge. Installing and operating ionospheric bottomside sounding systems, called ionosondes, requires a large amount of electricity, human resources, and the construction of an entire infrastructure of high-profile antennas. However, passively receiving a characterized or non-characterized sounder transmission is considerably more convenient. It requires a fraction of the power and resources, and utilizes lower-profile equipment that can be installed temporarily.
The IARPA Passive Ionospheric Non-Characterized Sounding (PINS) Challenge is an open innovation competition that asks Solvers to develop an algorithm that characterizes, monitors, and models ionospheric variation effects on high frequency emissions. The PINS Challenge invites Solvers from around the world to develop innovative solutions that can lead to a greater understanding of the ionosphere and the effects it has on our technology.
The goal of the Master Challenge is to derive specification of the HF sky-wave environment (the bottom-side ionosphere) across a longer circuit. This will be accomplished through passive reception of active sounders from an Oblique Incidence (OI). This process will require modification of the solver algorithms developed in the Explorer Challenge to determine ionospheric characteristics derived from more difficult OI datasets.