High-Altitude Platforms - Present Situation and Technology Trends

Abstract

High-altitude platforms (HAPs) are aircraft, usually unmanned airships or airplanes positioned above 20 km, in the stratosphere, in order to compose a telecommunications network or perform remote sensing. In the 1990 and 2000 decades, several projects were launched, but very few had continued. In 2014, 2 major Internet companies (Google and Facebook) announced investments in new HAP projects to provide Internet access in regions without communication infrastructure (terrestrial or satellite), bringing back attention to the development of HAP. This article aims to survey the history of HAPs, the current state-of-the-art (April 2016), technology trends and challenges. The main focus of this review will be on technologies directly related to the aerial platform, inserted in the aeronautical engineering field of knowledge, not detailing aspects of the telecommunications area.

User-centric JT-CoMP for High Altitude Platforms

“…Where ܲ ் is the transmit power emitted by the HAP, ‫ܩ‬ ் is the HAP antenna gain, ‫ܩ‬ ோ is the receiver antenna gain, while ܲ is path loss which will be explained later in (5).…”

“…It will use Airbus' aircraft to undertake telecom trials towards end 2018. Airbus has also scheduled a first full scale flight for their Zephyr T in 2018 [5], while AeroVironment Inc., a global leader in unmanned aircraft systems (UAS) recently announced a joint venture to fund development and production of solar-powered high-altitude unmanned aircraft systems with a contract value of $65 million [6].…”

Electromagnetic Field Based WPT Technologies for UAVs: A Comprehensive Survey

“…Near-field techniques are adopted for applications where the distance between the transmitter and receiver is On the other hand, unmanned aerial vehicles (UAV), commonly known as drones, are an emerging technology that can help future networks achieve better communication performances than the actual base station based networks [3,4]. In addition, due to their mobility and flexibility, UAVs have represented a key enabling technology for the development of a wide range of very innovative applications such as surveillance and military applications [5][6][7], search and rescue operations [8][9][10], remote sensing activities in which UAVs collect the data from sensors and deliver the collected data to ground base stations [11][12][13][14][15], construction and infrastructure inspection [16][17][18][19], precision agriculture for crop management and monitoring [12,[20][21][22], and the delivery of goods [23]. Generally, commercial UAVs come with lithium batteries that provide power for approximately 20-40 minutes of flying time [24].…”

Combined Trajectory and Propulsion Optimization for Solar-Regenerative High-Altitude Long Endurance Unmanned Aircraft

“…Electric, battery powered aircraft have been experimented with since the 1800s, and the addition of solar panels to electric aircraft has been studied since the 1970s. 3,4 Experimentation with solar-electric aircraft has significantly progressed since the 1800s. One notable SRHALE aircraft is NASA's Helios Prototype, a remotely piloted flying wing, which achieved a world record altitude of 96,843 feet in 2001, but experienced catastrophic failure over the Pacific Ocean in 2003.…”