Ophiolites, which have been tectonically emplaced along continental margins and island arcs, are significant to the understanding of mountain belt evolution. In the Himalayas, the ophiolitic suite of rocks occur along...Ophiolites, which have been tectonically emplaced along continental margins and island arcs, are significant to the understanding of mountain belt evolution. In the Himalayas, the ophiolitic suite of rocks occur along the Indussuture zone from Hanle in the southeast to Dras\|Kargil sector in the northwest and it represents the remnant of the compressed uplifted wedge of the oceanic crust between the two colliding continental masses, the Indian and the Asian plates.. These ophiolites are temporally and spatially correlated with the culminating phase of the Himalayan orogeny. The Indus River flows to its north separating the ophiolite from the Trans Himalayan litho\|units. Geological mapping in the hostile and inaccessible mountainous terrains of the Himalaya has always posed a great challenge to geologists. Nevertheless, a number of geologists have undertaken such arduous mapping expeditions in the past and prepared fairly good geological maps of these terrains .However there always existed disputes on the accuracy of lithological boundaries and structural details in these maps because many of these boundaries and structural features were completed through extrapolations and/or interpolations as the ruggedness and inaccessibility of a large part of the terrain forbid physical examination of every outcrop. It is in this context the potential of remote sensing, especially of satellite images, is to be appreciated.展开更多
During past 2 years, Chinese scientists have conducted a series of scientific,technical, and application research relating to earth observation for satellite and payload development, meteorological and environmental m...During past 2 years, Chinese scientists have conducted a series of scientific,technical, and application research relating to earth observation for satellite and payload development, meteorological and environmental monitoring, disaster reduction, resources surveying, and sustainable development of national economy and society. An short and incomplete review is given in this paper.展开更多
调制传递函数是红外遥感卫星像质评价的核心参数,但其在轨检测面临靶标温差稳定性不足与数据处理复杂两大挑战。提出一种基于三线靶标与温阶靶标协同的在轨调制传递函数(modulation transfer function,MTF)直接检测方法,通过靶标设计与...调制传递函数是红外遥感卫星像质评价的核心参数,但其在轨检测面临靶标温差稳定性不足与数据处理复杂两大挑战。提出一种基于三线靶标与温阶靶标协同的在轨调制传递函数(modulation transfer function,MTF)直接检测方法,通过靶标设计与模糊PID(proportional-integralderivative)温控算法,实现靶标温度均匀性(<0.5℃)、稳定性(±0.6℃)与重复性(>99%)的良好表现。基于傅里叶光学理论与辐射传输模型,结合“物方-像方调制度分离”计算原理,从遥感影像中直接提取奈奎斯特频率处MTF值,避免了传统方法中大气因素、数值微分以及参数拟合误差等对MTF检测的影响,为高分辨率红外卫星定量化应用提供了高精度技术支撑。展开更多
针对卫星遥感影像目标检测中,小目标检测精度低、漏检率高,以及实际应用场景中检测效率低等问题,文章提出一种基于改进YOLOv7(You Only Look Once)的卫星遥感影像多尺度目标检测方法。在检测网络中,聚焦提升小目标检测能力,添加类注意...针对卫星遥感影像目标检测中,小目标检测精度低、漏检率高,以及实际应用场景中检测效率低等问题,文章提出一种基于改进YOLOv7(You Only Look Once)的卫星遥感影像多尺度目标检测方法。在检测网络中,聚焦提升小目标检测能力,添加类注意力机制的卷积模块(ConvNeXt Block,CNeB),提升对小目标细粒度特征的提取及利用能力;同时,提出后处理机制,通过建立小目标与大目标的相互关系,实现使用单个模型对多种尺度目标进行检测。实验结果表明,在TGRS-HRRSD数据集4个小目标上,改进后的检测模型相较原始YOLOv7在平均精确率均值指标上提升了16.6个百分点。在检测特定大目标任务中,通过后处理机制,在保持精度的条件下,相较YOLT(You Only Look Twice)时间减少了70%。相较于主流的面向遥感影像的检测方法,该方法在检测多尺度目标上,检测精度更高、速度更快。展开更多
文摘Ophiolites, which have been tectonically emplaced along continental margins and island arcs, are significant to the understanding of mountain belt evolution. In the Himalayas, the ophiolitic suite of rocks occur along the Indussuture zone from Hanle in the southeast to Dras\|Kargil sector in the northwest and it represents the remnant of the compressed uplifted wedge of the oceanic crust between the two colliding continental masses, the Indian and the Asian plates.. These ophiolites are temporally and spatially correlated with the culminating phase of the Himalayan orogeny. The Indus River flows to its north separating the ophiolite from the Trans Himalayan litho\|units. Geological mapping in the hostile and inaccessible mountainous terrains of the Himalaya has always posed a great challenge to geologists. Nevertheless, a number of geologists have undertaken such arduous mapping expeditions in the past and prepared fairly good geological maps of these terrains .However there always existed disputes on the accuracy of lithological boundaries and structural details in these maps because many of these boundaries and structural features were completed through extrapolations and/or interpolations as the ruggedness and inaccessibility of a large part of the terrain forbid physical examination of every outcrop. It is in this context the potential of remote sensing, especially of satellite images, is to be appreciated.
文摘During past 2 years, Chinese scientists have conducted a series of scientific,technical, and application research relating to earth observation for satellite and payload development, meteorological and environmental monitoring, disaster reduction, resources surveying, and sustainable development of national economy and society. An short and incomplete review is given in this paper.
文摘调制传递函数是红外遥感卫星像质评价的核心参数,但其在轨检测面临靶标温差稳定性不足与数据处理复杂两大挑战。提出一种基于三线靶标与温阶靶标协同的在轨调制传递函数(modulation transfer function,MTF)直接检测方法,通过靶标设计与模糊PID(proportional-integralderivative)温控算法,实现靶标温度均匀性(<0.5℃)、稳定性(±0.6℃)与重复性(>99%)的良好表现。基于傅里叶光学理论与辐射传输模型,结合“物方-像方调制度分离”计算原理,从遥感影像中直接提取奈奎斯特频率处MTF值,避免了传统方法中大气因素、数值微分以及参数拟合误差等对MTF检测的影响,为高分辨率红外卫星定量化应用提供了高精度技术支撑。
文摘针对卫星遥感影像目标检测中,小目标检测精度低、漏检率高,以及实际应用场景中检测效率低等问题,文章提出一种基于改进YOLOv7(You Only Look Once)的卫星遥感影像多尺度目标检测方法。在检测网络中,聚焦提升小目标检测能力,添加类注意力机制的卷积模块(ConvNeXt Block,CNeB),提升对小目标细粒度特征的提取及利用能力;同时,提出后处理机制,通过建立小目标与大目标的相互关系,实现使用单个模型对多种尺度目标进行检测。实验结果表明,在TGRS-HRRSD数据集4个小目标上,改进后的检测模型相较原始YOLOv7在平均精确率均值指标上提升了16.6个百分点。在检测特定大目标任务中,通过后处理机制,在保持精度的条件下,相较YOLT(You Only Look Twice)时间减少了70%。相较于主流的面向遥感影像的检测方法,该方法在检测多尺度目标上,检测精度更高、速度更快。
