An Optical System of Area Array Static Infrared Earth Sensor

Abstract

The invention discloses an area-array static infrared earth sensor optical system. A refraction type optical structure is achieved by adopting three crescent moon lenses and an optical filter, and the field angle is 50 degrees and meets the satellite attitude measuring range requirement; four aspheric surfaces are adopted to correct off-axis aberration; the after working distance is larger than 10 mm, and therefore the optical filter, a detector and a thermal control system are conveniently installed. According to the system, the structure is simple, the weight is small, F# is not larger than 1.5 and meets the signal-to-noise ratio requirement of a product, distortion in the full view field is smaller than 0.5%, and the system is especially suitable for being used in infrared earth sensors in attitude orbit control systems of spacecrafts such as satellite spacecrafts.

Description

technical field [0001] The invention belongs to the technical field of infrared earth sensors for attitude and orbit control sub-systems of space vehicles such as satellite spacecraft, and relates to an optical system of an area array static infrared earth sensor for optical imaging of 14-16 micron far-infrared radiation of the earth. Background technique [0002] The infrared optical system of the area array static infrared earth sensor (infrared earth sensor, formerly known as infrared horizon) for space vehicles is used to optically image the far-infrared radiation of the earth's atmosphere, and the wavelength is generally 14 to 16 microns. Due to the weak radiant energy, the optical system needs to have a large relative aperture (small F#), few and thin lenses to improve the energy transmittance; it needs a relatively large field of view to increase the measurement range; it needs to suppress distortion and facilitate the satellite use. At present, there is no patent au...

AI Technical Summary

Problems solved by technology

[0007] (1) Although the F# of the optical system is 0.61, the aperture stop of the system is located behind the third lens instead of in front of the first lens. The real energy utilization rate of the system is too low, and the effective F# is only 2.4, resulting in the product The signal-to-noise ratio is too low to meet the requirements;

[0008] (2) The lens is composed of 4 mirrors, resulting in low optical transmittance;

[0009] (3) Although the product is designed with an f-θ optical structure, the imaging target is a surface object rather than a point object, resulting in excessive image distortion and cannot be used by satellites;

[0011] (1) The optical field of view is 21 degrees, resulting in a small optical measurement range and limited use of satellites;

[0012] (2) The rear working distance is too small (about 7mm), resulting in limited installation of optical filters and detectors, and limited installation of the detector's thermal control system;

[0013] (3) The optical system has a low resolution and can only be used for linear array infrared earth sensors, but cannot be used for area array static infrared earth sensors

[0015] (1) The aperture stop of the system is located in front of the second lens, not in front of the first lens. The real energy utilization rate of the system is too low, and the effective F# is 1.6;

[0016] (2) The system distortion is 8.8%, and image correction needs to be performed separately;

Images