Hybrid UAS

摘要

Unmanned airborne systems (UASs) -aircraft which fly without human pilots on board - have soared in popularity as surveying devices. Today they are applied in a wide variety of 2D and 3D mapping, inspection and monitoring tasks. A UAS is steered wirelessly by remote control, or follows a pre-specified air path. Whether it flies autonomously or is controlled remotely, the flight path is guided by a global navigation satellite system (GNSS) coupled with an inertial measurement unit (IMU). After flight, the recorded GNSS and IMU data is usually used to georeference the sensor data. The sensors on board include RGB cameras, near-infrared (NIR) cameras, thermal infrared (TIR) sensors and Lidar. Some UASs allow two or more sensors on board so that NIR images and Lidar points can be recorded at the same time. The rapid rise of the UAS ensued from a once-in-a-decade convergence of developments. Micro-electronics, auto-piloting, wireless communication, super-materials that are strong yet lightweight, compact digital cameras, image processing software, miniaturisation of GNSS and IMU systems, high-charge batteries - they all come together in a UAS. Markedly, the progress of power capacity of high-charge batteries is just 7% per year and, compared to the other UAS components, the battery notably adds to the payload. Supported by the accomplishments in artificial intelligence and computer vision, today's photogram-metric software enables high automation of the chain from flight planning, self-calibration of consumer-grade cameras and aero-trian-gulation up to the creation of DEMs and orthomosaics as well as their confluence: 3D landscape and city models.