Electromagnetic situation awareness and modeling for space–air–ground integrated networks

The ever-thriving advancement of the space-air-ground integrated network (SAGIN) has driven global connectivity toward greater heterogeneity, spurring a growing demand for spectrum resources. This evolution fosters the formation of the complex electromagnetic environment (CEME), leading to unprecedented challenges in managing and modeling the dynamic and diverse electromagnetic landscape. In response, this survey aims to provide the first comprehensive review of electromagnetic situation awareness and modeling in fields such as cognitive radio, integrated sensing and communication. Specifically, we summarize the evolution of spectrum situation awareness and the application of artificial intelligence in this field. Based on the generated spectrum situation map, we propose a comprehensive modeling method for dynamic and in-depth analysis of electromagnetic environments. Furthermore, we analyze and establish CEME models for diverse scenarios in SAGINs, considering factors like attenuation and interference. Finally, our exploration leads to the identification of promising future research directions, including technology development, specific communication scenarios and actual demand for covert communication, shedding some light on new insights and perspectives for advancing electromagnetic environment sensing and modeling.