按克林索求和计算大地水准面差距垂线偏差及重力异常   总被引：1，自引：0，他引：1  

管泽霖  鄂栋臣 《武汉大学学报(信息科学版)》1986,(4)

本文采用克林索求和的方法,应用三个重力模型计算了东经80°～120°和北纬20°～40°之间的大地水准面差距、垂线偏差和重力异常。各模型截取到22阶次为止,并且将各模型计算的5°×5°大地水准面差距和垂线偏差平均值进行了比较。另外还对模型计算的平均重力异常与实测的平均重力异常进行了比较。  相似文献   

解析延拓解及借助地形数据解的模型检验     

盛宗琪 《测绘学院学报》1989,(1)

本文利用位于参考平面上的无限延仲的三棱质体模型检验了解析延拓解(至一次项)和借助地形数据解在解算垂线偏差时的精度,并对这两个解在理论上和实用上的优劣程度进行了详细分析,得到了在计算垂线偏差时加入解析延拓解的一次项的精度还不如直接用法耶异常代入Venig Meinesz公式的精度高的新论点,并进一步验证了借助地形数据解的精确性和在实用中的优越性。  相似文献   

孔斜的地质因素分析     

夏宗清  赵善友 《中国煤田地质》2007,19(A01):42-45

通过钻孔测斜成果与地质成果的对比分析，认为地层的地质特征是地层造斜性质的根本因素；借助地质资料．可以对地层的造斜性质及造斜强度做出及时、有效的预测与评价，并据此对该钻孔所揭露地层进行了统一分类；另外还指出了在高精度垂直钻孔施丁巾塔式钻具组合的适用范围。  相似文献   

煤层气钻井中的几个关键技术问题浅析     

张相 《中国煤田地质》2007,19(5):68-69

在煤层气钻井施工中,基本上采用石油钻井工艺。根据煤层气开采要求及相关技术标准,对钻井中的几个关键问题进行了分析,并提出了相应的技术措施：如针对井斜因素的防斜措施,在工开钻进时的井液控制,煤层钻进时的钻进参数调整;下套管深度及接箍位置以及固井方法。这些措施,可有效提高钻效,提高成井质量。  相似文献   

Recovery of marine gravity anomalies from ERS1, ERS2 and ENVISAT satellite altimetry data for geoid computations over Norway     

A. Soltanpour  H. Nahavandchi  K. Ghazavi 《Studia Geophysica et Geodaetica》2007,51(3):369-389

Free-Air Anomalies (FAA) for the Norwegian marine area including some parts of the North Sea, the Norwegian Sea and the Barents Sea are computed from satellite altimetry data. A total of 84 cycles of ERS2 along-track data, 25 cycles of ENVISAT along-track data and high density ERS1 data during its geodetic mission are used. The new geopotential model from the Gravity Recovery and Climate Experiment (GRACE) mission, GGM02S (Tapely et al., 2005) is used to compute the long wavelength contributions of the geoid and the FAA. To correct data for mean dynamic topography, the available Levitus climatology model (Levitus and Boyer, 1994) is used. Corrected data are then used to compute along-track gradients in each cycle-pass to suppress the orbital and the atmospheric errors below the noise level of the altimeter. Resulted gradients are then stacked and the east-west and the north-south components of the deflection of verticals are computed where ascending and descending tracks meet each other. Finally, the inverse Vening-Meinesz formula is implemented on the gridded deflections to compute FAA. Results are then compared with available marine and airborne data. Standard deviations of ± 4.301 and ± 6.159 mGal in comparison with airborne and marine FAA were achieved. Thereafter, the derived anomalies are combined with marine and airborne FAA together with the land FAA to compute a fine resolution geoid for Norway and the surrounding marine areas. This geoid is evaluated over sea and land with the synthetic geoid (the geoid derived from the mean sea surface by subtracting the mean dynamic topography) and Global Positioning System (GPS)-levelling and the standard deviations of the differences are ± 20.9 and ± 12.8 cm respectively. ali.soltanpour@ntnu.no, hossein.nahavandchi@ntnu.no, kourosh.ghazavi@ntnu.no  相似文献   

定向钻探新型双滑块连续造斜器研究与应用          下载免费PDF全文

赵燕来  李忠 《探矿工程》2018,45(8):3-9

机械式连续造斜器是定向钻探技术手段之一,目前常用的LZ型连续造斜器采用单滑块与孔壁支撑,径向制动扭矩小,造斜过程中容易发生角位移,影响造斜效果,并且造斜强度不易调节。为解决造斜稳定性问题,特别设计研制了一种新型双滑块连续造斜器,该造斜器卡固稳定,造斜强度可调,器具经过野外试验验证工作可靠。新型连续造斜器的创新点在于：（1）采用双滑块结构形式,在国内还没有先例,已经取得实用新型专利;（2）增加了造斜强度调节机构,可根据施工需要调节;（3）通过工作弹簧与上滑块组件之间的螺纹连接方式来实现上滑块回位;（4）采用分压接头控制上滑块侧向力,在满足卡固要求情况下,降低造斜钻进阻力。新型双滑块连续造斜器为国内外首创,具有自主知识产权,使用效果良好,具备较好的开发推广前景。  相似文献   

全球及局部海洋扰动重力反演的快速解析方法     

翟振和  孙中苗  王兴涛 《测绘学报》2015,44(8):827-832

从经典边值问题理论及球谐函数理论出发,在空域推导获得了由大地水准面高以及垂线偏差计算扰动重力的解析计算公式,为利用卫星测高数据反演海洋扰动重力提供了理论基础。针对全球海洋区域和局部海洋区域的扰动重力反演,在前人已有工作基础上,提出了改进的基于一维FFT的精确快速算法,保证了计算结果与原解析方法完全一致,且计算速度提高约20倍。该算法在提高计算效率的同时避免了由于引入FFT而产生的混叠、边缘效应问题,而且对观测数据的序列长度没有硬性要求,使得应用更加灵活。利用EGM2008地球重力场模型分别生成了2.5'分辨率大地水准面高数据和垂线偏差数据,按照本文提出的改进方法(采用全球积分计算)分别反演获得了全球及局部海洋区域的扰动重力。经比较分析,由大地水准面和垂线偏差分别反演获得的扰动重力其差异在0.8×10^-5 m/s²以内,这说明两种反演方法是基本一致的,但在数据包含系统误差的情况下,由垂线偏差反演扰动重力具有一定优势。  相似文献   

Early NEO Deflections: A Viable, Lower-Energy Option     

Andrea Carusi 《Earth, Moon, and Planets》2005,96(1-2):81-94

This paper presents the results of some numerical simulations of deflection of Near-Earth Objects (NEOs) on a collision course with the Earth. These simulations show that it is possible, in principle, to deviate even large objects applying in succession moderate impulses resulting in small velocity variations of the impactor. The use of this technique of "distributed deflection" is always applicable, provided that the impact has been detected many years in advance, and that the object passes its perihelion many times before impact. The modest values of the required velocity variations may allow to use low-energy methods for deflection, such as kinetic energy, thus suggesting an interesting, very flexible solution to this difficult problem.  相似文献   

Deflection of near-Earth asteroids by kinetic energy impacts from retrograde orbits     

Colin R. McInnes 《Planetary and Space Science》2004,52(7):587-590

Previous studies of non-nuclear diversion of near Earth asteroids have largely ignored the use of pure kinetic energy impacts, partly due to apparent limits on impact speeds of 10-. Here, I will consider the use of a near-term solar sail to deliver an inert projectile onto a retrograde solar orbit, thus raising impact speeds to at least . Such high-energy orbits increase the energy liberated during impact by a factor of 40 or more, while reducing the required projectile mass by at least 95%. This considerable reduction in projectile mass allows kilometre-sized asteroids to be diverted with current launch vehicles, near-term technologies and at a cost comparable to a modest deep space mission.  相似文献   

面板局部屈曲的船体双层板架整体屈曲分析   总被引：1，自引：0，他引：1  

曾晓辉  柳春图等 《海洋工程》2001,19(3):60-67

首先应用von-Kurman大挠度薄板方程，对有初挠度的船体板进行后屈曲特性分析，以此为基础，导出屈曲后板的减缩有效宽度，进而用减综有效宽度作为双层板架中受压纵杵的带板宽度，将双层板架模型化为四边弹性转角约束的正交异性板，考虑横向剪切变形的影响，提出了一种求解双层板架临界应力的方法。  相似文献