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This article presents a comprehensive summary of the regulatory environment confronting low earth orbit, non-geostationary satellite orbit (LEO NGSO) communication satellites and critically evaluates analogies from terrestrial spectrum management as possibilities for LEO NGSO satellites. This analysis provides a framework for empirical analysis of the alternatives considered. 

The development of a multistatic radar system for the Colorado Zephyr Meteor Radar Network is described in this article. This system relies on recent developments in the field of meteor radar, including advancements in software-defined radio-based radar receivers, multistatic wind retrieval, coded constant- wave transmit signals, and transmit-side interferometry. We present the current status of a prototype multistatic radar transmitter deployed in Platteville, Colorado, and a forward look toward how it can inform the design of a large-scale radar network. 

Abstract. The Hunga Tonga–Hunga Ha′apai volcano erupted on 15 January 2022, launching Lamb waves and gravity waves into the atmosphere. In this study, we present results using 13 globally distributed meteor radars and identify the volcanogenic gravity waves in the mesospheric/lower thermospheric winds. Leveraging the High-Altitude Mechanistic general Circulation Model (HIAMCM), we compare the global propagation of these gravity waves. We observed an eastward-propagating gravity wave packet with an observed phase speed of 240 ± 5.7 m s−1 and a westward-propagating gravity wave with an observed phase speed of 166.5 ± 6.4 m s−1. We identified these waves in HIAMCM and obtained very good agreement of the observed phase speeds of 239.5 ± 4.3 and 162.2 ± 6.1 m s−1 for the eastward the westward waves, respectively. Considering that HIAMCM perturbations in the mesosphere/lower thermosphere were the result of the secondary waves generated by the dissipation of the primary gravity waves from the volcanic eruption, this affirms the importance of higher-order wave generation. Furthermore, based on meteor radar observations of the gravity wave propagation around the globe, we estimate the eruption time to be within 6 min of the nominal value of 15 January 2022 04:15 UTC, and we localized the volcanic eruption to be within 78 km relative to the World Geodetic System 84 coordinates of the volcano, confirming our estimates to be realistic.