The Potential for a Networked Ionospheric Sounding Constellation

• Published in: Space Weather 2022-05, Vol.20 (5), p.n/a
• Main Author: Chartier, A. T.
• Format: Article
• Language: English
• Subjects: Antennas; constellation; Cubesat; Data analysis; Density; F region; Ionosphere; Ionospheric sounding; Mars atmosphere; Mars ionosphere; Mars missions; Measurement techniques; mission; Planetary ionospheres; Plasmapause; Plasmasphere; Radio occultation; Radio signals; Satellite constellations; Satellites; Scale height; Signal paths; Signal processing; Software radio; sounding; Spatial data
• ISSN: 1542-7390; 1539-4964; 1542-7390
• DOI: 10.1029/2022SW003089

A novel networked sounding constellation mission concept is proposed. Radio sounding is the original sensing method that proved the existence of the ionosphere. Satellite‐borne sounders provided the first global observations of the terrestrial ionosphere and plasmasphere, as well as the Martian ionosphere. Networked sounding, where signals are transmitted and received across multiple instruments, has been used on the ground since the first days of ionospheric observation. This paper proposes networked sounding from space, to produce measurements of the F‐layer peak, enhanced E‐layers, regions of turbulent structuring, the topside scale height (or transition height) and potentially the plasmapause. The principal advantage of sounding over other methods is direct measurement of the peak density, where a networked implementation greatly increases spatial data coverage because it provides multiple unique signal paths through the ionosphere at different frequencies. Major advances in satellite software‐defined radio, deployable antennas, signal processing and data analysis have been made in recent years, such that a networked sounding constellation could be built at realistic cost—either as a hosted payload on commercial buses or on dedicated CubeSats. Plain Language Summary This paper sets out the potential for a novel mission to deliver global, high‐resolution measurements of the ionosphere. The measurement technique is based on the original ionospheric instruments, which operated by reflecting radio signals off the ionosphere to determine its height and density. This technique has been proven by previous satellite missions. The novel aspect is to perform “networked” sounding from space, whereby signals are reflected off the ionosphere obliquely between satellites as well as vertically. The benefit in terms of data coverage is potentially huge, because the network produces up to a maximum of N + N(N − 1)/2 links from N satellites. The data quality is better than other methods because the peak density is measured directly, without need for inversion. In a simulation, networked sounding yields 26 million ionospheric peak density measurements per day from a 132‐satellite constellation. This is a 100‐fold improvement over the yield expected from the same constellation using radio occultation. Key Points A novel networked sounding constellation mission concept is proposed Networked sounding potentially yields huge benefits in terms of ionospheric observational cov