Due to the inability of manufacturing a single monolithic mirror at the 10-meter scales,segmented mirrors have become indispensable tools in modern astronomical research.However,to match the imaging performance of the...Due to the inability of manufacturing a single monolithic mirror at the 10-meter scales,segmented mirrors have become indispensable tools in modern astronomical research.However,to match the imaging performance of the monolithic counterpart,the sub-mirrors must maintain precise co-phasing.Piston error critically degrades segmented mirror imaging quality,necessitating efficient and precise detection.To ad-dress the limitations that the conventional circular-aperture diffraction with two-wavelength algorithm is sus-ceptible to decentration errors,and the traditional convolutional neural networks(CNNs)struggle to capture global features under large-range piston errors due to their restricted local receptive fields,this paper pro-poses a method that integrates extended Young’s interference principles with a Vision Transformer(ViT)to detect piston error.By suppressing decentration error interference through two symmetrically arranged aper-tures and extending the measurement range to±7.95μm via a two-wavelength(589 nm/600 nm)algorithm.This approach exploits ViT’s self-attention mechanism to model global characteristics of interference fringes.Unlike CNNs constrained by local convolutional kernels,the ViT significantly improves sensitivity to inter-ferogram periodicity.The simulation results demonstrate that the proposed method achieves a measurement accuracy of 5 nm(0.0083λ0)across the range of±7.95μm,while maintaining an accuracy exceeding 95%in the presence of Gaussian noise(SNR≥15 dB),Poisson noise(λ≥9 photons/pixel),and sub-mirror gap er-ror(Egap≤0.2)interference.Moreover,the detection speed shows significant improvement compared to the cross-correlation algorithm.This study establishes an accurate,robust framework for segmented mirror error detection,advancing high-precision astronomical observation.展开更多
The Principles of coherent interference suppression are presented by a three-sensor array. The formulae of extracting expected signals from strong interference are derived. The selection of sensor space is discussed a...The Principles of coherent interference suppression are presented by a three-sensor array. The formulae of extracting expected signals from strong interference are derived. The selection of sensor space is discussed and then relationships between the space and frequency point, at which the signals can be extracted, are given. When expected signals are band- limit, the conditions of the selected sensor space, which should be satisfied, are given. Lastly, Performance of interference suppression is analyzed when the amplitude of interference power spectra of signals Received by three sensors fluctuates, and the expressions of relative error of the extracted signals and processing gain are derived. The theoretical and simulation results show that signals can be extracted from strong background interference without any information about signals and interference expect for the arriving direction of signals, that the space between sensors should be smaller than half wavelength of upper limit freqency when the expected signals are band-limit, and that performance of extracting signals will decline with the increase of fluctuation of interference spectrum amplitude.展开更多
文摘Due to the inability of manufacturing a single monolithic mirror at the 10-meter scales,segmented mirrors have become indispensable tools in modern astronomical research.However,to match the imaging performance of the monolithic counterpart,the sub-mirrors must maintain precise co-phasing.Piston error critically degrades segmented mirror imaging quality,necessitating efficient and precise detection.To ad-dress the limitations that the conventional circular-aperture diffraction with two-wavelength algorithm is sus-ceptible to decentration errors,and the traditional convolutional neural networks(CNNs)struggle to capture global features under large-range piston errors due to their restricted local receptive fields,this paper pro-poses a method that integrates extended Young’s interference principles with a Vision Transformer(ViT)to detect piston error.By suppressing decentration error interference through two symmetrically arranged aper-tures and extending the measurement range to±7.95μm via a two-wavelength(589 nm/600 nm)algorithm.This approach exploits ViT’s self-attention mechanism to model global characteristics of interference fringes.Unlike CNNs constrained by local convolutional kernels,the ViT significantly improves sensitivity to inter-ferogram periodicity.The simulation results demonstrate that the proposed method achieves a measurement accuracy of 5 nm(0.0083λ0)across the range of±7.95μm,while maintaining an accuracy exceeding 95%in the presence of Gaussian noise(SNR≥15 dB),Poisson noise(λ≥9 photons/pixel),and sub-mirror gap er-ror(Egap≤0.2)interference.Moreover,the detection speed shows significant improvement compared to the cross-correlation algorithm.This study establishes an accurate,robust framework for segmented mirror error detection,advancing high-precision astronomical observation.
文摘The Principles of coherent interference suppression are presented by a three-sensor array. The formulae of extracting expected signals from strong interference are derived. The selection of sensor space is discussed and then relationships between the space and frequency point, at which the signals can be extracted, are given. When expected signals are band- limit, the conditions of the selected sensor space, which should be satisfied, are given. Lastly, Performance of interference suppression is analyzed when the amplitude of interference power spectra of signals Received by three sensors fluctuates, and the expressions of relative error of the extracted signals and processing gain are derived. The theoretical and simulation results show that signals can be extracted from strong background interference without any information about signals and interference expect for the arriving direction of signals, that the space between sensors should be smaller than half wavelength of upper limit freqency when the expected signals are band-limit, and that performance of extracting signals will decline with the increase of fluctuation of interference spectrum amplitude.
