Hyperspectral remote sensing technology can acquire an object's geometric, radiation, and spectral information. This technology is an important technique in Earth observations and is increasingly becoming important in applications of natural resource survey, environment and disaster monitoring, precision agriculture, oceans and costal monitoring, and urban planning. In the past decades, several advanced hyperspectral imaging systems from airborne (e.g., AVIRIS, Hymap, OMIS, and PHI) to spaceborne (e.g., EO-1/Hyperion and PROBA/CHRIS) platforms have been designed, built, and operated globally. On the one hand, airborne hyperspectral imager has been developed into commercial operation stage. Examples of international companies that develop airborne systems are Spectra Vista Corporation of America, Specim of Finland, and ITRES Research of Canada. On the other hand, GF-5/AHSI, which is a pioneer in Chinese spaceborne hyperspectral imager, has first realized wide spectrum, wide swath width, and high detection sensitivity. It marks a new era ever since the appearance of EO-1/Hyperion in 2000. In the future, the outlook for hyperspectral remote sensing technique is as follows: (1) The development of large-scale plane array detector, optical machining detection, and signal processing has improved not only the spectral resolution but also the spatial resolution and swath width of hyperspectral imaging. Hyperspectral imager's spectrum range will cover from UV to LWIR to obtain more abundant spectral information of ground objects, all-day reflectance, and emission spectral characteristics. In addition, the integrated calibration methods of laboratory, in-orbit, and the Earth, the Sun, the Moon, the cold air, and the stars are becoming increasingly abundant and refined to ensure the application efficiency of hyperspectral imager at higher performance. The hyperspectral imaging technology with super wide width and higher resolution also puts forward higher requirements for the further development of large-scale detectors and large-aperture optics with wide working band range. (2) The development of information, imaging, and optical processing technology has introduced new beam splitting technologies and developed the core beam splitting elements from the mature dispersion and interference type to the diversified direction. Many novel optical splitting schemes, such as Acousto-optic Tunable Filter (AOTF), Liquid Crystal Tunable Filter (LCTF), Linear Variable Filter (LVF), Integrated Stepwise Filter (ISF), Tunable Fabry-Perot Filter (TFPF) and computational spectral imaging system based on compressed sensing, are available at present. These spectroscopic image methods are still in the stage of laboratory experiments. An increasing attention has also been paid to the chip-level hyperspectral spectroscopy, which combines light splitting with photoelectric conversion. (3) With the advances in the artificial intelligence, machine learning data process, such as neural network and deep learning, has become a trend with hyperspectral imaging to construct an 'intelligent' hyperspectral remote sensing satellite system. This technology will integrate the ability of automatic optimization of onboard load parameters and automatic real-time processing of onboard data and product generation. Meanwhile, the amount of remote sensing data obtained is explosively growing with the increase in resolution and information dimensions of hyperspectral imaging instruments. Big data feature is significant. Data transmission is an important issue in successfully using the effective data mining and information extraction and improving the efficiency of data compression in the future. (4) The development of small UAV and micro-nano satellite technology has developed hyperspectral imaging toward a low-cost, flexible, integrated, and real-time technology. At present, the light and small hyperspectral imaging technology based on small UAV is greatly demanded and valuable in the fields of agricultural, forestry diseases and insect pests' detection, target search, and rescue and relief. Micro-nano satellites have low cost and short development cycle and can conduct complex space remote sensing tasks. The combination of hyperspectral imaging and micro-nano satellite technologies will promote the integration of multi-functional structure and space exploration payload. Lightweight, integrated, and systematized hyperspectral remote sensing with space networking and all-time detection will play an important role in the future. It will provide the possibility for hyperspectral remote sensing satellites to enter the commercial field. Many new principles, schemes, and technologies are being implemented and applied in hyperspectral imaging. The integrated acquisition and processing ability of multiple information is also greatly enhanced. The hyperspectral load is gradually developing in the direction of large field of view, large relative aperture, high resolution, and high quantification. The cost of hyperspectral remote sensing technology will be greatly reduced with its continuous development and maturity. The commercial application of this technology will also be an important direction of future development. © 2021, Science Press. All right reserved.
