浅谈手持GPS在地质矿区勘查中的应用

手持GPS未经参数校正时定位精度为80~120 m,利用测量控制点进行参数校正后定位精度可提高至5 m以内,在地质勘查中熟练运用手持GPS将大大提高野外工作效率。     

动态坐标校正法提高手持GPS精度

实验表明部分手持GPS外符合定位精度较低,尤其两次观测同一点的互差一般都会超过其标称精度,在测定地质孔位或小比例尺填图中会出现较大误差.实践过程中,发现手持GPS的外符合精度明显低于内符合精度,前者误差有时高达30m左右,而且不稳定,随机性很差;后者坐标相对误差一般均能达到3～5 m的精度.利用手持GPS内符合定位精度高的特点提出一种动态坐标校正法,即每次测量都以几个已知点为校正点重复测量,以此计算坐标转换时的相应参数进行坐标纠正,从而提高手持GPS与地图坐标的吻合程度.     

1∶5万土壤测量工作流程及相关软件的应用

在1∶5万土壤测量工作中,通过使用GPS定位技术及GIS Office、Mapgis、section、GeoIPAS等地质专业计算机应用软件,大大提高工作效率,并保证成果质量。其工作流程可分为:室内准备的地形图校正、采样点的布置、采样点属性提取;野外作业的GPS参数设置、设计采样点位坐标导入手持GPS、实际采样点位坐标投影到地形图、样品加工;室内资料整理及成果图件编制。     

在地勘测量中应用RTK技术

传统光学仪器测量需要测量点之间通视，数据需要手工记录和进行繁琐的后处理。RTK技术将GPS接收机、现场手持计算机和无线电数据链相结合，实时提供cm级测量精度，可大大提高工作效率，减轻劳动强度。它由基准站、流动站和数据处理系统组成。在基准站安置GPS接收机，对GPS卫星进行连续观测，将观测数据通过无线电传输设备实时地发送给用户观测站。GPS接收机在接收卫星信号的同时接收基准站传输的观测数据，实时地计算并显示用户站的三维坐标及其精度。RTK技术可以替代常规测量为地质勘查工作快速提供可靠、高精度的测量成果。     

手持GPS在地质调查中的具体应用实践——以黔西南某地金矿普查为例

笔者在黔西南某地金矿的地质调查中通过对手持GPS的运用实践,总结出应用技术路线。认为正确设置和采集原始点坐标,并计算调查区的校正参数是关键,验证误差评价不可少,乃是精度的保证、应用的基础。利用已知点校正时,原始点数据采集要点是正确设置对应坐标系统的目标椭球,投影设为测区对应的中央子午线,其它参数选项卡全关闭,同时,采集原始点数据时,最好为10次及以上平滑方式、差分3D状态下采集。在调查区实践中,坐标转换方法使用经典的"一步法",计算得到四参数及校正参数数据,并应用于项目工程,用其它已知点验证,其平均偏差为±2.9 m,精度较高,完全符合地质勘查规范的要求。经过参数校正后的手持GPS,完全可以取代地形图人工定点。米级带SBAS功能多星机型实际精度接近亚米级的单星机型,支持多星的手持机定位快,精度高,因此,笔者建议今后使用多星和SBAS定位技术的GPS,以期取得事半功倍的效果。     

手持GPS三参数计算

在野外地质测量工作中,使用手持GPS(它属于WGS-84大地坐标系)导航时,当需要尽可能高精度的测量时,需要根据已知道的当地参数,和最近的已知点坐标(1954年北京坐标系或1980西安坐标系),通过计算,求取坐标转换的3个参数。     

手持GPS在地质勘查中的应用研究

GPS是20世纪70年代出现的新一代空间卫星导航定位系统,由空间星座、地面监控系统和用户系统3个部分组成。手持GPS以其灵便、定位精度高和全天候等特点使其在地质勘查工作中的应用较为普及。结合工作实践,阐述了手持GPS定位的基本原理、常用坐标系、坐标转换方法、定位精度、使用注意事项,给同行的类似工作提供参考。     

GPS测量在铁路施工控制网中的应用

白浩铁路一期工程线路自桑锡线的白音库伦车站引出,直至门迪诺尔,全线长约52.253km。根据野外施工条件采用GPS定位技术进行E级网平面控制测量,高程控制采用几何水准方法,在施测时加测一个临时点以增加图形强度。测量施工采用4台S82-2008双频GPS接收机按静态观测方法进行同步观测,观测时间控制在45min~60min。根据GPS网平差后坐标和点位精度分析,该项勘测工程控制网设计与施工措施合理,测量结果满足规范所规定的各项限差要求。白浩铁路一期工程GPS施测控制网的布设方法为GPS在沙漠地区特殊条件下的应用提供了一成功例证。     

浅谈RTK技术在城市测量中的实际操作

RTK（Real Time Kinematic）即实时动态测量系统,是GPS测量技术与数据传输技术的结合,是GPS测量技术中的一个新突破。RTK测量技术是以载波相位观测量为根据的实时差分GPS测量技术。其基本思想是：在基准站上设置1台GPS接收机。对所有可见GPS卫星进行连续地观测,并将其观测数据通过无线电传输设备,     

GPS在浅海地区高精度重力测量中的应用

根据浅海地区大比例尺高精度重力测量的需要,本文首先提出重力测量对平面位置和导航精度的要求。在对比了几种中、近程无线电定位系统后,论述了应用GPS技术的可行性和经济效益。文章接着介绍了我们选用的GPS接收机主要技术指标与检测结果,并以工区的部分实测结果进一步说明了应用GPS的优越性。为了提高定位精度,扩大应用范围,文章最后还提出了改进措施。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861