Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static b...Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static background subtraction based on a median image technique has been used to extract moving space objects prior to the tracking operation, as this is computationally efficient. The main disadvantage of this technique is that it is not robust to variable illumination conditions. In this article, we propose an approach for tracking small and dim space debris in the context of a dynamic background via one of the optical telescopes that is part of the space surveillance network project, named the Asia- Pacific ground-based Optical Space Observation System or APOSOS. The approach combines a fuzzy running Gaussian average for robust moving-object extraction with dim-target tracking using a particle- filter-based track-before-detect method. The performance of the proposed algorithm is experimentally evaluated, and the results show that the scheme achieves a satisfactory level of accuracy for space debris tracking.展开更多
To simultaneously obtain high-resolution multi-wavelength （from visible to near infrared） tomographic images of the solar atmosphere, a high-performance multi-wavelength optical filter has to be used in solar imagin...To simultaneously obtain high-resolution multi-wavelength （from visible to near infrared） tomographic images of the solar atmosphere, a high-performance multi-wavelength optical filter has to be used in solar imaging telescopes. In this Letter, the fabrication of the multi-wavelength filter for solar tomographic imaging is described in detail. For this filter, Ta2O5 and SiO2 are used as high- and low-index materials, respectively, and the multilayer structure is optimized by commercial Optilayer software at a 7.5° angle of incidence. Experimentally, this multi-wavelength optical filter is prepared by a plasma ion-assisted deposition technique with optimized deposition parameters. High transmittance at 393.3, 396.8, 430.5, 525, 532.4, 656.8, 705.8, 854.2, 1083, and 1565.3 nm, as well as high reflectance at 500 and 589 nm are achieved. Excellent environmental durability, demonstrated via temperature and humidity tests, is also established.展开更多
基金support from The World Academy of Sciences(TWAS)the Chinese Academy of Sciences(CAS)+1 种基金the AsiaPacific Space Cooperation Organization(APSCO)supported as part of a national major scientific research equipment development project of China(No.ZDYZ2013-2)
文摘Although tracking with a passive optical telescope is a powerful technique for space debris observation, it is limited by its sensitivity to dynamic background noise. Traditionally, in the field of astronomy, static background subtraction based on a median image technique has been used to extract moving space objects prior to the tracking operation, as this is computationally efficient. The main disadvantage of this technique is that it is not robust to variable illumination conditions. In this article, we propose an approach for tracking small and dim space debris in the context of a dynamic background via one of the optical telescopes that is part of the space surveillance network project, named the Asia- Pacific ground-based Optical Space Observation System or APOSOS. The approach combines a fuzzy running Gaussian average for robust moving-object extraction with dim-target tracking using a particle- filter-based track-before-detect method. The performance of the proposed algorithm is experimentally evaluated, and the results show that the scheme achieves a satisfactory level of accuracy for space debris tracking.
基金partially supported by the West Light Foundation of the Chinese Academy of Sciences
文摘To simultaneously obtain high-resolution multi-wavelength （from visible to near infrared） tomographic images of the solar atmosphere, a high-performance multi-wavelength optical filter has to be used in solar imaging telescopes. In this Letter, the fabrication of the multi-wavelength filter for solar tomographic imaging is described in detail. For this filter, Ta2O5 and SiO2 are used as high- and low-index materials, respectively, and the multilayer structure is optimized by commercial Optilayer software at a 7.5° angle of incidence. Experimentally, this multi-wavelength optical filter is prepared by a plasma ion-assisted deposition technique with optimized deposition parameters. High transmittance at 393.3, 396.8, 430.5, 525, 532.4, 656.8, 705.8, 854.2, 1083, and 1565.3 nm, as well as high reflectance at 500 and 589 nm are achieved. Excellent environmental durability, demonstrated via temperature and humidity tests, is also established.
