Stellar images will deteriorate dramatically when the sensitive elements of wide-field survey telescopes are misaligned during an observation, and active alignment is the key technology to maintain the high resolution...Stellar images will deteriorate dramatically when the sensitive elements of wide-field survey telescopes are misaligned during an observation, and active alignment is the key technology to maintain the high resolution of wide-field sky survey telescopes. Instead of traditional active alignment based on field-dependent wave front errors, this work proposes a machine learning alignment metrology based on stellar images of the scientific camera,which is more convenient and higher speed. We first theoretically confirm that the pattern of the point-spread function over the field is closely related to the misalignment status, and then the relationships are learned by twostep neural networks. After two-step active alignment, the position errors of misalignment parameters are less than5 μm for decenter and less than 5″ for tip-tilt in more than 90% of the cases. The precise alignment results indicate that this metrology provides a low-cost and high-speed solution to maintain the image quality of wide-field sky survey telescopes during observation, thus implying important significance and broad application prospects.展开更多
The Dux gene plays an important role in mouse embryo development(De Iaco et al.,2017;Hendrickson et al.,2017;Whiddon et al.,2017).It participates in the maternal-to-zygotic transition(MTZ),which mainly includes matern...The Dux gene plays an important role in mouse embryo development(De Iaco et al.,2017;Hendrickson et al.,2017;Whiddon et al.,2017).It participates in the maternal-to-zygotic transition(MTZ),which mainly includes maternal transcript degradation and zygotic genome activation(ZGA)and is the key process for embryonic development.Approximately 11-100 copies of the DUX4 gene form a tandem cluster in the human genome(Snider et al.,2009,2010).展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. U1931207 and 12173062)the project of Multi-channel Photometric Survey Telescope。
文摘Stellar images will deteriorate dramatically when the sensitive elements of wide-field survey telescopes are misaligned during an observation, and active alignment is the key technology to maintain the high resolution of wide-field sky survey telescopes. Instead of traditional active alignment based on field-dependent wave front errors, this work proposes a machine learning alignment metrology based on stellar images of the scientific camera,which is more convenient and higher speed. We first theoretically confirm that the pattern of the point-spread function over the field is closely related to the misalignment status, and then the relationships are learned by twostep neural networks. After two-step active alignment, the position errors of misalignment parameters are less than5 μm for decenter and less than 5″ for tip-tilt in more than 90% of the cases. The precise alignment results indicate that this metrology provides a low-cost and high-speed solution to maintain the image quality of wide-field sky survey telescopes during observation, thus implying important significance and broad application prospects.
基金supported by the National Key R&D Program of China(2017YFC1002003)the project sponsored by the National Natural Science Foundation of China(31601197)。
文摘The Dux gene plays an important role in mouse embryo development(De Iaco et al.,2017;Hendrickson et al.,2017;Whiddon et al.,2017).It participates in the maternal-to-zygotic transition(MTZ),which mainly includes maternal transcript degradation and zygotic genome activation(ZGA)and is the key process for embryonic development.Approximately 11-100 copies of the DUX4 gene form a tandem cluster in the human genome(Snider et al.,2009,2010).
