Opti-electronic loads with multi-sensor are widely applied in the fields of atmosphere sounding and optical remote sensing. For the purpose of achieving high performance, miniaturization and light weight of multi-band photoelectric load, this paper proposes a structure with common aperture and partial common optical path, then light enters each subsequent light path after decomposed. This structure can improve system stability and avoids boresight errors caused by multi-apertures. The essay analyzes the aberration formula and initial structural parameter’s calculation method of the three-mirror system with the constraint of afocal condition, then eliminate the center occlusion through shifting the optic aperture and design a compact off-axis three-mirror afocal optical system with a folding mirror. The system magnification is 6×, the max aperture is 140 mm, and the max field of view is 4°×2.1°. The modulation transfer function of optical system reaches more than 90% of the diffraction limit. The mirror surface adopts paraboloid and hyperboloid, which are easy to be processed and tested. The size of system is 167×145×211 mm, and the structure is compact enough to meet the application requirements.
In order to project the laser command information to the proper distance , so a laser zoom projective lens with variable total track optical system is designed in the carrier-based aircraft landing system. By choosing the zoom structure, designing of initial structure with PW solution, correcting and balancing the aberration, a large variable total track with 35~× zoom is carried out. The size of image is invariable that is φ25m, the distance of projective image is variable from 100m to 3500m. Optical reverse design, the spot is less than 8μm, the MTF is near the diffraction limitation, the value of MTF is bigger than 0.4 at 50lp/mm.
Based on the principium of light field imaging, there designed a objective lens and a microlens array for gathering the light field feature, the homologous ZEMAX models was also be built. Then all the parameters were optimized using ZEMAX and the simulation image was given out. It pointed out that the position relationship between the objective lens and the microlens array had a great affect on imaging, which was the guidance when developing a prototype.
A visible, MWIR, long focal, oblique view and focusing optical system of aerial camera is described, and in this paper we design an innovative optical system with common optical path and catadioptics configuration. The focal length of this optical system is 1.45m in the visible waveband (0.7~0.9μm,) and 0.61m in MWIR waveband (3.7~4.8μm), and the oblique view scanning range is within 20km~100km. To meet the requirements for the sharp imaging quality under the circumstances of high altitude environment and real time variable range, this aerial camera is focused by making back cutoff length longer to add a mirror, then MTF of optical system is all above 0.4 in Nyquest frequency.
During the research of hyper-spectral imaging spectrometer, how to process the huge amount of image data is a difficult problem for all researchers. The amount of image data is about the order of magnitude of several hundreds megabytes per second. With the development of multi-core computer, parallel computing on multi-core computer is increasingly applied in large-scale data processing. In this paper, we give a detailed discussion of parallel computing technology, we also apply this technology to the data processing of hyper-spectral image data. Experimental results show that the speed of data processing is apparently improved. Our research has significant meaning for the engineering application of hyper-spectral imaging spectrometer.
Spectral calibration and radiometric calibration is an important part in the data processing of the windowing Fourier transform imaging spectrometer, it can ensure that the spectral curve output from spectrometer are more closely to target spectrum. The main idea of spectral calibration is using a monochromatic source whose wavelength is known, in the same way, radiometric calibration can be achieved by using radiation source whose radiation characteristic is known.
In this paper, we propose a set of methods of spectral calibration and radiometric calibration. In order to carry out spectral calibration, we use monocharomator to scan several sample points near the position of every spectral channel of imaging spectrometer, and then we employ Gaussian fitting function to determine the central wavelength and bandwidth of every spectral channel. In order to carry out radiometric calibration, we employ panchromatic light source and integrating sphere, at the position of every spectral channel of imaging spectrometer, we measure the response ability of spectrometer to radiation. The calibration accuracy is carefully analyzed. Experimental results show that calibration accuracy meet the given requirements.
Theory about the Thermal Infrared Imaging Fourier Transform Spectrometer has been discussed,
and then we found the Interference efficiency is an important factor related to SNR of Thermal
Infrared Imaging Fourier Transform. The Interference efficiency involved in transverse shear
splitting. After study of this kind of beam splitting, some formulas about Thermal Infrared
Imaging Fourier Transform Spectrometer has been found, then the simulation modes were done.
At the end, Interference efficiency of Imaging Fourier Transform Spectrometer was calculated.
The relationship between interference efficiency and SNR was simply given.
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