HAP Networks for the Future: Applications in Sensing, Computing, and Communication

High Altitude Platforms (HAPs) are a major advancement in non-terrestrial networks, offering broad coverage and unique capabilities. They form a vital link between satellite systems and terrestrial networks and play a key role in next-generation communication technologies. This study reviews HAP network applications, focusing on advanced airborne communications, integrated sensing, and airborne informatics. Our survey assesses the current state of HAP-centric applications by examining data processing, network performance, computational and storage requirements, economic feasibility, and regulatory challenges. The analysis highlights the evolving role of HAPs in global communication and identifies future research directions to support their deployment.