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51.
52.
应用ArcGIS实现高程异常等值线图的数字化和属性入库,建立高程异常数据库;在对距离加权、最小二乘插值、梯度插值3种数学方法对比分析的基础上,在面向对象的Visual Basic6.0环境下应用MapObjects地理信息控件,实现高程异常值的自动查询及显示、缩放、漫游等相关功能。 相似文献
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通过分析虚拟参考站技术和主辅站技术的不足,提出了一种新的网络RTK技术——增强参考站技术(ARS).分析了这种技术的原理并阐述了该技术中改正数的生成方法,同时,提出了一种基于RTCM编码的适合于该技术的改正数编码格式.在此基础上,分析了该技术的RTK定位精度、数据传输效率和系统可靠性,从理论上说明了增强参考站的技术优势.最后,以四川综合GPS服务网(SIGN)的子网数据对该技术进行了验证,结果表明,该技术具有高定位精度、高数据传输效率的特点,是一种理想的网络RTK技术. 相似文献
55.
论述了1:50 000松花江、嫩江干流条带图的数据格式转换、水利专题图层的设计和用JAVA语言编程调用电子地图数据的方法. 相似文献
56.
针对观测序列的异方差和时相关特性相互影响但又难以并行建模的问题,提出了一种迭代、序贯处理异方差和时相关问题的随机模型建模方案.实验结果显示,该方法较好地解决了异方差和时相关特性无法并行建模的难题.极大地消除了多路径及系统残余误差对GPS定位成果的影响,增加了基线数据处理的可靠性. 相似文献
57.
内蒙古自治区桌子山煤田赋存着较为稀缺的煤种一焦煤,煤田内存在的火区不仪烧掉了宝贵的焦性煤炭资源,给煤矿生产带来严重的事故隐患,对当地生态环境也造成极大的破坏。经查明区内有26处子火区,分布面积约760万m^2,通过煤田地质特征、煤质特征、地表指示特征、同位素氡气的浓度相对分布特征、物性特征分析了区内煤层发火原因,根据桌子山煤田火区特点,建议采用浅剥、深灌与覆盖相结合的灭火方法,并对火区进行动态监测。 相似文献
58.
Michiaki Sugita Tetsuya Hiyama Nobuhiko Endo Shao-Fen Tian 《Boundary-Layer Meteorology》1995,73(1-2):145-158
Careful micrometeorological measurements on an empty parking lot allowed determination of the surface fluxes of sensible heatH and of momentum by applying profile equations derived from Monin-Obukhov similarity theory with two sets of the stability correction function for momentum
m
and sensible heat
h
. These fluxes were compared with reference values ofH independently determined by means of an eddy correlation technique. In general, better agreement was found betweenH values derived from profiles with the stability functions of Brutsaert (1992) and referenceH values, than when the Businger-Dyer functions were used to deriveH. The disagreement in the latter comparison was especially serious under strongly unstable conditions, with the value ofy=–z/L (wherez is the height andL is the Obukhov length) larger than 10. A closer look at the procedure for calculatingH from the profiles revealed that the large differences between theH values derived with these two different versions of the stability correction functions were caused by the small differences of the
h
values, and not by the larger differences of the
m
values. This result stems from the strong sensitivity of the resultingH values on the choice of
h
. 相似文献
59.
60.
Joo Carvalho Joo Cabral Rui Gonalves Luís Torres Luís Mendes-Victor 《Tectonophysics》2006,418(3-4):277-297
The study region is located in the Lower Tagus Valley, central Portugal, and includes a large portion of the densely populated area of Lisbon. It is characterized by a moderate seismicity with a diffuse pattern, with historical earthquakes causing many casualties, serious damage and economic losses. Occurrence of earthquakes in the area indicates the presence of seismogenic structures at depth that are deficiently known due to a thick Cenozoic sedimentary cover. The hidden character of many of the faults in the Lower Tagus Valley requires the use of indirect methodologies for their study. This paper focuses on the application of high-resolution seismic reflection method for the detection of near-surface faulting on two major tectonic structures that are hidden under the recent alluvial cover of the Tagus Valley, and that have been recognized on deep oil-industry seismic reflection profiles and/or inferred from the surface geology. These are a WNW–ESE-trending fault zone located within the Lower Tagus Cenozoic basin, across the Tagus River estuary (Porto Alto fault), and a NNE–SSW-trending reverse fault zone that borders the Cenozoic Basin at the W (Vila Franca de Xira–Lisbon fault). Vertical electrical soundings were also acquired over the seismic profiles and the refraction interpretation of the reflection data was carried out. According to the interpretation of the collected data, a complex fault pattern disrupts the near surface (first 400 m) at Porto Alto, affecting the Upper Neogene and (at least for one fault) the Quaternary, with a normal offset component. The consistency with the previous oil-industry profiles interpretation supports the location and geometry of this fault zone. Concerning the second structure, two major faults were detected north of Vila Franca de Xira, supporting the extension of the Vila Franca de Xira–Lisbon fault zone northwards. One of these faults presents a reverse geometry apparently displacing Holocene alluvium. Vertical offsets of the Holocene sediments detected in the studied geophysical data of Porto Alto and Vila Franca de Xira–Lisbon faults imply minimum slip rates of 0.15–0.30 mm/year, three times larger than previously inferred for active faults in the Lower Tagus Valley and maximum estimates of average return periods of 2000–5000 years for M 6.5–7 co-seismic ruptures. 相似文献