The study of underwater in-situ detection is an important research trend in underwater detection. In view of the design requirements of the spectral data acquisition system for underwater in-situ detection, this paper used the software and hardware co-design method, from two aspects of software and hardware. A prototype system of spectral data acquisition system based on Xilinx Zynq chip and linear array CCD detector was designed and implemented. Through theoretical analyzing, experimental debugging and verification analyzing, the results shown that the system could collect and store the spectral data in real time. It also had the characteristics of low noise and had a small electronic structure, which laid a foundation for the spectral data acquisition of underwater in-situ detection.
Large aperture static interferometer spectrometer (LASIS) use the method of push-boom to get the geometric and spectral characteristics of ground target, the particularity of principle requires the movement of satellite must be in the same direction with spectrometers detectors. Drift angle of satellite leading to abnormal image shifts in the column direction which should be perpendicular to the detector and can seriously affect the spectrum recovery precision of collected data. This paper analyzes the influence mechanism of drift angle for spectrum recovery precision. Simulation based on the actual on-orbit data analyses the effects of different drift angle of relative mean deviation and relative secondary deviation rehabilitation of the spectrum, besides the influence of spectral angle similarity. These studies have shown that, when the lateral deviation due to the drift angle on the across track is less than 0.3 pixel, the effect for the relative mean deviation of the inversive spectra will be no more than 7%. when the lateral deviation due to the drift angle on the across track is larger than one pixel, even though the resampling correction is proceeded, the restored spectral data cube still shows an relative mean error more than 10%, which seriously affect the availability of spectral data.
Spectral imaging technology has made great achievements in applications of earth observation and space target detection, with the further development of research, the requirement that People tend to get more material properties about target is also improving rapidly, so getting more characters of the target is continuous pursuit goal for the instruments of optical remote sensing. Polarization is one of the four main physical properties of light including intensity, frequency and phase . It has very important significance for remote sensing observations such as improving the accuracy of target recognition. This paper proposes on a spectropolarimeter system based on Sagnac interferometer, and introduces the main aspects related to System components, working principle, optical design, adaptive spectrum extraction algorithm, state of polarization extraction methods. Also get the data of polarization spectral imaging by using the instruments designed by the principle .By processing these data I have got the combined polarization image and target spectral curves, achieved a good result. It is a new attempt to obtain polarization spectral image by integrated measuring system. Then thoroughly solve the traditional shortcoming of spectropolarimeter, such as asynchronous detecting, poor stability and vibration, poor energy efficiency. It can be applied to many kinds of fields. Simultaneously the paper puts forward some relevant new points in the future research for this kind of principle.
Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. It has great potential for developing the larger aperture and lightweight telescope. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different point in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light(from 8μm-12μm) to a common focus with 4.6° field of view. At last, the diffuse spot size and MTF function provide diffractive-limited performance.
Proc. SPIE. 9142, Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics: Optical Imaging, Remote Sensing, and Laser-Matter Interaction 2013
Diffraction image technology is an updated technology. It has more potential for developing the larger aperture and lightweight telescope than the conventional refractive and reflective optics. In order to develop a large aperture diffractive telescope, the key is to solve the problem of large aperture lens stitching. Different stitching patterns have different effects on the image quality. However, the stitching pattern for diffractive telescope is different from the conventional refractive and reflective telescope. This paper, for the first time, studies the theory of stitching pattern for diffractive telescope. On the basis of theoretical analysis, a long-wavelength infrared diffractive telescope of segmented-lens is designed and for the first time, good results through stitching experiments have been achieved. According to theoretical analysis and experiment verification, the paper gives the best stitching pattern on diffractive telescope.