Front-mounted optical system of satellite-borne differential absorption spectrometer

Abstract

The invention relates to a front-mounted optical system of a satellite-borne differential absorption spectrometer. The front-mounted optical system consists of a front-mounted telescope and a relay reflector. The front-mounted telescope further consists of a primary mirror and a secondary mirror, and the primary mirror and the secondary mirror of the telescope as well as the relay reflector are all designed in an off-axis manner and respectively have the off-axis angles of 4 DEG, -6 DEG and 5 DEG; radiant light of a target object passes through an entrance pupil diaphragm and irradiates to the primary mirror, and light beams are reflected to the secondary mirror of the front-mounted telescope by a polarization scrambler through an aperture diaphragm, then are reflected to the relay reflector through a slit, and finally are focused to an incident slit of a spectrometer by the relay reflector; and then a wide view field telescope system of the two mirrors is realized through controlling positions of diaphragms and the off-axis angles. The front-mounted optical system of the satellite-borne differential absorption spectrometer has the advantages of fewer mirrors, high utilization efficiency of radiant energy, wide range of working spectrum and no chromatic correction, thus the measuring accuracy and the surveying distinguishability of the whole system are enhanced; and in addition, the whole optical volume is compact, thereby greater convenience is brought for a successive optical system.

Description

technical field [0001] The invention belongs to the field of optical measurement methods, in particular to a pre-optical system of a differential absorption spectrometer that collects and gathers ultraviolet scattered light from the earth's surface and sky, and is mainly used in space-borne or airborne differential absorption spectrometers. Background technique [0002] At present, the commonly used front optical systems at home and abroad are off-axis aspheric three-mirror system (TMA), card type catadioptric system and short focal length refractive optical system. The technology of the cassette system is relatively mature, consisting of two coaxial aspheric surfaces and a refractive field lens, but there is a central block, the resolution is slightly lower, and the stray light is larger, and an external hood is required; the TMA system is a new type developed in recent years. The optical system is composed of 3 aspheric mirrors, without central occlusion, high resolution, ...

AI Technical Summary

Problems solved by technology

However, the general coaxial reflection system has two major deficiencies: one is that there is an inevitable central occlusion; the other is that the field of view with excellent image quality is small

The field of view of the TMA three-mirror system is also relatively small, and because it is composed of aspheric mirrors, processing and assembly are not easy

[0004] Therefore, the field of view of the current front-end optical system is too small, the volume of the overall optical system is too large, and the arrangement of the follow-up imaging spectrometer is unreasonable.

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