A Concept of 2U Spaceborne Multichannel Heterodyne Spectroradiometer for Greenhouse Gases Remote Sensing

We present the project of a 2U CubeSat format spaceborne multichannel laser heterodyne spectroradiometer (MLHS) for studies of the Earth’s atmosphere upper layers in the near-infrared (NIR) spectral range (1258, 1528, and 1640 nm). A spaceborne MLHS operating in the solar occultation mode onboard CubeSat platform, is capable of simultaneous vertical profiling of CO2, H2O, CH4, and O2, as well as Doppler wind measurements, in the tangent heights range of 5–50 km. We considered the low Earth orbit for the MLHS deployment and analyzed the expected surface coverage and spatial resolution during one year of operations. A ground-based prototype of the MLHS for CO2 and CH4 molecular absorption measurements with an ultra-high spectral resolution of 0.0013 cm−1 is presented along with the detailed description of its analytical characteristics and capabilities. Implementation of a multichannel configuration of the heterodyne receiver (four receivers per one spectral channel) provides a significant improvement of the signal-to-noise ratio with the reasonable exposure time typical for observations in the solar occultation mode. Finally, the capability of building up a tomographic picture of sounded gas concentration distributions provided by high spectral resolution is discussed.

ГЕНЕРАТОРЫ ИЗОБРАЖЕНИЙ ДЛЯ БЕЗМАСКОВОЙ ЛИТОГРАФИИ

Многие годы технологи фотолитографии работают на установках проекционной или контактной печати. Им трудно представить, что за последнее время конструктора создали такие лазерные генераторы изображений, которые по точности переноса топологии превзошли все ранее известные способы. Многолучевые лазерные генераторы изображений позволяют на практике внедрять в серийное производство безмасковую литографию. For many years, photolithography process engineers have been operating the tools for wafer projection imaging and tools for proximity exposure. It may be hard for them to imagine the recently designed laser pattern generators which exceed the accuracy of all previously known patterning techniques. Multichannel laser pattern generators make it possible to introduce maskless lithography into mass production.

ON A FUNDAMENTAL EVALUATION OF A UAV EQUIPPED WITH A MULTICHANNEL LASER SCANNER

Unmanned aerial vehicles (UAVs), which have been widely used in various fields such as archaeology, agriculture, mining, and construction, can acquire high-resolution images at the millimetre scale. It is possible to obtain realistic 3D models using high-overlap images and 3D reconstruction software based on computer vision technologies such as Structure from Motion and Multi-view Stereo. However, it remains difficult to obtain key points from surfaces with limited texture such as new asphalt or concrete, or from areas like forests that may be concealed by vegetation. A promising method for conducting aerial surveys is through the use of UAVs equipped with laser scanners. We conducted a fundamental performance evaluation of the Velodyne VLP-16 multi-channel laser scanner equipped to a DJI Matrice 600 Pro UAV at a construction site. Here, we present our findings with respect to both the geometric and radiometric aspects of the acquired data.

Использование многоканальных лазерных комплексов для создания некогерентной накачки в комптоновских лазерах на свободных электронах рентгеновского диапазона

It is used that there is great potential in the use of multichannel laser complexes for incoherent pumping of X-ray Compton free-electron lasers based on stimulated wave backscattering on high-current moderately relativistic electron beam. The relative width of the pump spectrum must be comparable with that of the energy spectrum of the electron beam, which ensures involvement of a significant fraction of particles into the scattering process and, hence, high efficiency of their kinetic energy conversion into X-ray radiation.