The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic ne...The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic networks.If the discrete observed velocity field is obtained,the velocity related fields,such as dilatation rate and maximum shear strain rate,can be estimated by applying varied mathematical approaches.This study applied Akaike's Bayesian Information Criterion(ABIC)method to calculate strain rate fields constrained by GPS observations in the southeast Tibetan Plateau.Comparison with results derived from other three methods revealed that our ABIC-derived strain rate fields were more precise.The maximum shear strain rate highlighted the Xianshuihe–Xiaojiang fault system as the main boundary for the outward migration of material in southeastern Tibet,indicating rotation of eastern Tibet material around the eastern Himalaya rather than whole extrusion along a fixed channel.Additionally,distinct dilatation rate patterns in the northeast and southwest regions of the fault system were observed.The northeast region,represented by the Longmenshan area,exhibited negative dilatational anomalies;while the southwest region,represented by the Jinsha River area north of 29°N,displayed positive dilatational anomalies.This indicates compression in the former and extension in the latter.Combined with deep geophysical observations,we believe that the upper and lower crusts of the Jinsha River area north of 29°N are in an entire expanding state,probably caused by the escape-drag effect of material.The presence of a large,low-viscosity region south of 29°N may not enable the entire escape of the crust,but instead result in a differential escape of the lower crust faster than the upper crust.展开更多
针对增强型互补金属氧化物半导体(intensified complementary metal oxide semiconductor,ICMOS)相机中光纤光锥和CMOS传感器关键组合器件响应标校及其在实际应用中的降噪问题,采用K均值异常点剔除、最小二乘理想线性响应拟合、多项式...针对增强型互补金属氧化物半导体(intensified complementary metal oxide semiconductor,ICMOS)相机中光纤光锥和CMOS传感器关键组合器件响应标校及其在实际应用中的降噪问题,采用K均值异常点剔除、最小二乘理想线性响应拟合、多项式响应误差补偿拟合的成像系统响应标校方法,有效降低了系统固定模式噪声、单个像素响应非线性、整场像素响应非均匀性对ICMOS相机响应输出的影响。采用金字塔真实图像降噪网络(pyramid real image denoising network,PRIDNet)的成像系统图像降噪方法,进一步抑制了ICMOS相机应用过程随机噪声对相机成像效果的影响。研究结果表明:与传统方法中仅做固定模式噪声处理的标校方法相比,应用本文标校方法,像素平均线性度指标提高了约7%,整场响应均匀度指标提高为原来的2.2倍。与其他类型网络相比,采用PRIDNet降噪方法,其峰值信噪比在不同环境光输入条件下均提高了3%~5%。展开更多
基金supported by grants from the Ministry of Science and Technology(Grant Nos.2021FY100101,2019QZKK0901)the National Natural Science Foundation of China(Grant Nos.41941016,42230312,42020104007)China Geological Survey(Grant No.DD20221630).
文摘The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic networks.If the discrete observed velocity field is obtained,the velocity related fields,such as dilatation rate and maximum shear strain rate,can be estimated by applying varied mathematical approaches.This study applied Akaike's Bayesian Information Criterion(ABIC)method to calculate strain rate fields constrained by GPS observations in the southeast Tibetan Plateau.Comparison with results derived from other three methods revealed that our ABIC-derived strain rate fields were more precise.The maximum shear strain rate highlighted the Xianshuihe–Xiaojiang fault system as the main boundary for the outward migration of material in southeastern Tibet,indicating rotation of eastern Tibet material around the eastern Himalaya rather than whole extrusion along a fixed channel.Additionally,distinct dilatation rate patterns in the northeast and southwest regions of the fault system were observed.The northeast region,represented by the Longmenshan area,exhibited negative dilatational anomalies;while the southwest region,represented by the Jinsha River area north of 29°N,displayed positive dilatational anomalies.This indicates compression in the former and extension in the latter.Combined with deep geophysical observations,we believe that the upper and lower crusts of the Jinsha River area north of 29°N are in an entire expanding state,probably caused by the escape-drag effect of material.The presence of a large,low-viscosity region south of 29°N may not enable the entire escape of the crust,but instead result in a differential escape of the lower crust faster than the upper crust.
文摘针对增强型互补金属氧化物半导体(intensified complementary metal oxide semiconductor,ICMOS)相机中光纤光锥和CMOS传感器关键组合器件响应标校及其在实际应用中的降噪问题,采用K均值异常点剔除、最小二乘理想线性响应拟合、多项式响应误差补偿拟合的成像系统响应标校方法,有效降低了系统固定模式噪声、单个像素响应非线性、整场像素响应非均匀性对ICMOS相机响应输出的影响。采用金字塔真实图像降噪网络(pyramid real image denoising network,PRIDNet)的成像系统图像降噪方法,进一步抑制了ICMOS相机应用过程随机噪声对相机成像效果的影响。研究结果表明:与传统方法中仅做固定模式噪声处理的标校方法相比,应用本文标校方法,像素平均线性度指标提高了约7%,整场响应均匀度指标提高为原来的2.2倍。与其他类型网络相比,采用PRIDNet降噪方法,其峰值信噪比在不同环境光输入条件下均提高了3%~5%。
