不同定位模式下北斗单基站CORS定位精度分析     

李畅 《测绘与空间地理信息》2021,44(z1):114-116

单基站CORS相对于多基站CORS具有成本低、建设时间短等优点.本文对北斗系统单基站RTD/RTK定位模型进行分析研究,并通过对实测数据对算法进行分析验证,RTD定位在东方向精度可以达到0.3 m,北方向精度可以达到0.4 m,高程精度可以达到0.8 m.RTK定位在平面精度可以达到1 cm,高程精度可以达到3 cm,可以满足不同类型的导航定位需求.  相似文献   

地基合成孔径雷达技术研究与初步应用     

王晓波  李畅  关辅兴 《测绘与空间地理信息》2021,44(z1):237-239,244

阐述了地基合成孔径雷达测量的技术原理和应用方向,归纳了地基雷达形变测量的主要技术流程.通过实地测试验证其精度,地基合成孔径雷达技术具备探测毫米-亚毫米级形变信息的能力,地基雷达设备稳定可靠,具有广泛的应用前景.最后揭示地基合成孔径雷达技术在变形监测及预警中的问题,同时提出下一步的工作安排.  相似文献   

南阿尔金地区早古生代中酸性侵入岩的岩石成因及其对构造演化的指示意义     

徐楠  吴才来  刘畅 《地质学报》2023,97(12):4067-4084

南阿尔金造山带位于塔里木盆地和柴达木盆地之间,是中国西北地区重要的俯冲-碰撞杂岩带,其早古生代构造演化过程是近年来的研究热点之一,然而,洋壳俯冲的时限一直存在争议。本文对茫崖石英二长岩开展岩石学、地球化学、锆石U-Pb年代学和锆石Lu-Hf同位素地球化学研究,探讨其岩石成因及成岩时的构造环境。样品显示高碱、富钾、低钛、贫铁及Nd-Ta-Ti异常等与钾玄岩相似的地球化学特征,成岩年龄为511～495 Ma, ε_Hf(t)主要为-3.51～-0.08,少量介于0.04～1.69之间。我们认为俯冲洋壳到达角闪岩相边界时释放大量水并上升进入地幔楔,导致地幔楔橄榄岩发生角闪石化交代作用,由于地幔楔沿俯冲带向下拖曳而温度升高,角闪石化橄榄岩熔融形成的熔体在上升过程诱发上地壳物质部分熔融,壳源岩浆混合少量幔源岩浆形成了石英二长岩,该期花岗岩是对造山带从大洋岛弧环境向活动大陆边缘过渡的岩石学响应。因此,南阿尔金洋壳可能在约517 Ma前已经开始俯冲。  相似文献   

Mass motion in upper solar chromosphere detected from solar eclipse observation     

Zhi Li  Zhongquan Qu  Xiaoli Yan  Guangtao Dun  Liang Chang 《Astrophysics and Space Science》2016,361(5):159

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Control of tetrahedron satellite formation flying in the geosynchronous orbit using solar radiation pressure     

Yong-Gang Hou  Ming-Jiang Zhang  Chang-Yin Zhao  Rong-Yu Sun 《Astrophysics and Space Science》2016,361(4):144

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Complex organics in space from Solar System to distant galaxies     

Sun?KwokEmail author 《Astronomy and Astrophysics Review》2016,24(1):8

Recent observational and experimental evidence for the presence of complex organics in space is reviewed. Remote astronomical observations have detected \(\sim \)200 gas-phased molecules through their rotational and vibrational transitions. Many classes of organic molecules are represented in this list, including some precursors to biological molecules. A number of unidentified spectral phenomena observed in the interstellar medium are likely to have originated from complex organics. The observations of these features in distant galaxies suggests that organic synthesis had already taken place during the early epochs of the Universe. In the Solar System, almost all biologically relevant molecules can be found in the soluble component of carbonaceous meteorites. Complex organics of mixed aromatic and aliphatic structures are present in the insoluble component of meteorites. Hydrocarbons cover much of the surface of the planetary satellite Titan and complex organics are found in comets and interplanetary dust particles. The possibility that the early Solar System, or even the early Earth, have been enriched by interstellar organics is discussed.  相似文献   

Geochemical characterization of Archaean amphibolites from the eastern part of Anshan–Benxi iron producing area,northeastern China: implication for tectonic setting of BIFs     

En‐De Wang  Chang‐Ik Han  Jian‐Ming Xia  Jian‐Fei Fu  Guang‐Su Li  San‐Shi Jia  Ye‐Kai Men 《Geological Journal》2016,51(3):480-498

The Anshan–Benxi iron producing area, which is located at the northeastern margin of the North China Craton, is the main distribution area of Archaean BIFs in China. In their eastern part, including the Gongchangling and Waitoushan deposits, BIFs mainly are hosted in the Archaean middle Anshan Group. Amphibolites are widely distributed in the iron‐bearing rock series, reflecting the tectonic setting of BIFs. Amphibolites not only have MORB‐like compositional characteristics, but also have island arc‐like ones, and they are consistent with back‐arc basin basalts (BABB). In the study area, the protolith of amphibolites belongs to Okinawa‐type BABB; it indicates that tectonic setting of BIFs is the intra‐continental back‐arc basin. In the study area, the formation of sedimentary basins for BIFs had been associated with oceanic plate subduction. Amphibolites from Gongchangling deposit are characterized by relative enrichments in LILE and LREE, and depletions in HFSE. This indicates that they had a relatively large influence of subduction in their formation. Amphibolites from Waitoushan deposit are characterized by relative enrichments in LILE without conspicuous depletions in HFSE, indicating relatively low subduction rates. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

夏季两次低槽冷锋型暴雨成因对比分析   总被引：1，自引：0，他引：1  

郑丽娜  孙兴池  孟伟 《气象科技》2015,43(6):1133-1141

利用常规观测资料和NCEP 1°×1°再分析资料,对对流层低层无低涡、无低空急流配置的低槽和冷锋影响下2004年7月29—30日后倾槽和2004年8月3—4日前倾槽两次暴雨过程的成因进行了对比分析,结果表明: 虽然两次过程对流层中低层形势非常相近,但在空间结构上却存在显著差异。后倾槽锋区向冷空气倾斜且成3段锋,其中,第1段锋在850 hPa以下,冷空气虽较弱,但对整个降水过程起抬升触发作用,暴雨区出现在该段锋移动方向的前沿,即地面辐合线呈气旋性弯曲的流线密集处;前倾槽锋区完整,湿斜压锋区向暖区倾斜,暴雨区出现在锋前1～2个纬距处,即地面辐合线右侧偏南气流密集带中。两次过程低层均有强的水汽输送,存在高温高湿区,925 hPa比湿均达15 g〖DK〗·kg-1以上,所不同的是,后倾槽暴雨区位于水汽通量大值区、等〖WTBX〗θe〖WTBZ〗密集线前沿及风场辐合明显的水汽辐合区内,而前倾槽暴雨区则位于水汽通量等值线密集带中的水汽辐合区、〖WTBX〗θe〖WTBZ〗暖舌的舌尖和风场辐合处,但更偏向暖空气一侧。此外,暴雨易发生在山区或海岸线等特殊地形抬升的区域。  相似文献   

基于51单片机的气象数据无线传输系统的设计开发     

左湘文  薛筝筝  肖建辉  黄玉学  孙嘉楠 《气象科技》2015,43(5):829-832

针对自动气象站探测数据短距离无线传输的需要,设计了一套气象数据无线传输系统。系统由发送器、接收器组成,基于51单片机和NRF905无线射频控制芯片开发。该系统对不同型号自动气象站具有良好的自适应能力。实现了气象数据的无线传输、显示和存储。经测试系统在环境适应性和传输能力方面均达到了设计要求,系统运行稳定、可靠。本文从工作原理,系统构成,硬件设计、单片机程序设计及系统测试几个方面对传输器开发方法进行了详细介绍。  相似文献   

Plausible influence of Atlantic Ocean SST anomalies on winter haze in China   总被引：3，自引：0，他引：3  

Dong Xiao  Ying Li  Shaojia Fan  Renhe Zhang  Jiaren Sun  Yan Wang 《Theoretical and Applied Climatology》2015,122(1-2):249-257

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