The Land Mobile Earth-Space Channel

Research on mobile satellite and high-altitude platform (HAP) systems (MSHSs) has recently proliferated because of the allocation of additional spectrum, the intense standardization efforts from different international institutes, the detailed studies pursued by the European [European Space Agency (ESA)], French (CNES), and Japanese (JAXA) space agencies, and the commercial impact of some of the corresponding system implementations. A survey of mobile satellite systems is provided. Enhanced land mobile Earth-space (LMES) channels encompassing a variety of geometries, frequency bands, and propagation environments are critical for developing and assessing the performance of these new MSHS paradigms. In this article, we provide a survey of the state-of-the-art measurement campaigns, modeling approaches, and generative methods concerning the LMES channel and pinpoint future research directions. We refer to LMES since, due to the close similarities they exhibit, we present channels from both geostationary (GEO) satellites and quasi-stationary HAPs. Most of the cited models apply in both cases. General emphasis is on statistical/physical narrow-band models, which is the norm in LMES channels.