拟准检定法及其在测量中的应用初探     

黄康钰  王义琴  唐海龙  张俊 《测绘与空间地理信息》2017,(2):43-44

经典最小二乘平差假定观测数据中不含有粗差,但随着现代测绘技术发展,数据采集的自动化程度越来越高,对数据采集过程进行人工干预较难实现,观测结果包含粗差在所难免。本文探讨利用拟准检定法进行粗差探测的原理、特点及优势,并通过模拟算例,验证了拟准检定法处理粗差的有效性。  相似文献   

测量数据的质量控制理论探讨   总被引：4，自引：1，他引：4  

欧吉坤 《测绘工程》2001,10(2):6-10

从可靠性和粗差检测两方面分析了质控制理论研究的进展；介绍了新的统一的可靠性指标，它完全由系统的结构决定，不包含受主观因素影响的概率因子（非中心参数λ0)。详细介绍了拟准检定法的原理和实施办法，特别是初选拟准观测的一些技巧，通过一个算例比较了拟准检定法与假设检验的三种形式的计算结果，后者存在部分粗差不能发现的问题，而前者能发现全部粗差，效果较好。  相似文献   

Traditional and New Ways to Handle Uncertainty in Geology   总被引：3，自引：0，他引：3  

Bárdossy  George  Fodor  János 《Natural Resources Research》2001,10(3):179-187

The paper presents an overview of the main types of uncertainty in geology. The best guess and uncertainty oriented approaches are outlined. Traditional methods of uncertainty analysis—deterministic and probabilistic—are discussed with special references to their limitations in geology. New mathematical methods, developed during the last decades are suitable to handle uncertainty in geology in scalar, spatial, and spatial-temporal conditions, such as uncertainty intervals, fuzzy sets, probability bounds, neural networks, hybrid arithmetic and fuzzy geostatistics. Geological applicability of these methods is discussed. Uncertainty of risk analysis for geological purposes also is outlined.  相似文献   

太白山北坡成土因素及不同土壤垂直带谱的比较   总被引：1，自引：2，他引：1  

雷梅  陈同斌  冯立  常庆瑞  阎湘 《地理研究》2001,20(5):583-592

在系统地考察太白山北坡地质、地貌、气候和植被等成土因素的基础上,总结和回顾了用土壤发生分类和土壤系统分类两种分类体系划定的太白山北坡土壤垂直带谱。根据最新的土壤系统分类,太白山北坡的土壤垂直带谱是:暗瘠寒冻雏形土(3500～3767m)———暗沃寒冻雏形土(3300～3500m)———酸性湿润雏形土(2500～3300m)———简育湿润淋溶土(1400～2500m)———简育干润淋溶土(<1400m)。分析、比较表明:两种体系有密切联系,均以成土因素为依据,建立在土壤发生学理论之上;与土壤地理发生分类相比,土壤系统分类用可以度量的诊断层和诊断特性进行土壤分类,不仅能够反映出山地土壤成土因素的垂直变化趋势,而且避免了太白山北坡土壤类型鉴定上的许多歧义。  相似文献   

LaCoste—Romberg G型重力仪的漂移探讨     

沈晶  刘端法 《地震地磁观测与研究》1992,13(2):67-74

本文针对LaCoste-Romberg G型重力仪(下文简称为LCR-G型重力仪)长期、中期、短期及静态漂移问题进行了探讨。从大量观测数据及曲线中发现,LCR-G147、LCR-G570及LCR-G596三台重力仪的漂移均存在着年变化。对8年来观测数据分析后,得出结论:如果同一测段两个往返时间差不超过1小时,一般就不必进行漂移改正,并不影响观测结果的可靠性。  相似文献   

门限自回归模型在地震预报中的应用初探     

和宏伟 《地震研究》1992,15(2):154-161

本文简要介绍了应用门限自回归方法处理浑沌时间序列,建立了浑沌时间序列自回归预报模型,并用其进行外推预报的基本方法及步骤。作者运用该方法建立了云南及滇西、滇东和滇西南等三个片区的半年最大震级序列的震级预报模型。由此预测了1991年上半年模型相应地区可能发生的最大地震震级。  相似文献   

Accuracy of kinematic wave and diffusion wave approximations for time-independent flows     

V. P. Singh  V. Aravamuthan 《水文研究》1995,9(7):755-782

Errors in the kinematic wave and diffusion wave approximations for time-independent (or steady-state) cases of channel flow were derived for three types of boundary conditions: zero flow at the upstream end, and critical flow depth and zero depth gradient at the downstream end. The diffusion wave approximation was found to be in excellent agreement with the dynamic wave approximation, with errors in the range 1–2% for values of KF (? 7.5), where K is the kinematic wave number and F₀ is the Froude number. Even for small values of KF (e.g. KF²₀ = 0.75), the errors were typically less than 15%. The accuracy of the diffusion wave approximation was greatly influenced by the downstream boundary condition. The error of the kinematic wave approximation was found to be less than 13% in the region 0.1 ? x ? 0.95 for KF = 7.5 and was greater than 30% for smaller values of KF (? 0.75). This error increased with strong downstream boundary control.  相似文献   

Inoceramid bivalves and biostratigraphy of the upper Albian and lower Cenomanian of the United States Western Interior Basin     

《Cretaceous Research》2016

Inoceramid bivalves of the upper Albian and lower Cenomanian of the United States Western Interior are revised, Eleven species-level taxa and three genera are described. Two new species, Gnesioceramus mowriensis, characterizing the Mowry Shale of the early, but not the earliest, Cenomanian, and Posidonioceramus merewetheri, of the lower Cenomanian, and on new genus, Posidonioceramus, are recognised. The Western Interior inoceramid species from this interval are strongly endemic and are not good tools for long-distance correlations, although they are very effective in regional dating.In terms of the inoceramid biostratigraphy, middle and upper parts of the upper Albian can be referred to the Gnesioceramus Biozone, represented by G. comancheanus (Cragin) and G. bellvuensis (Reeside). These taxa are endemic to the Western Interior and some adjacent areas (Gulf Coast; Greenland?), but are closely allied to the cosmopolitan species, Gnesioceramus anglicus (Woods). At approximately the Albian-Cenomanian boundary, the endemic clade of ‘Inoceramus’ nahwisi appears, now referred to the newly erected Posidonioceramus, resulting in a distinct P. nahwisi biozone. This zone corresponds to the lower part of the ammonite Neogastroplites’ stratigraphic range. Gnesioceramids re-appear in the early Cenomanian. Close to base of the Cenomanian, for the first in the Western Interior, the genus Inoceramus, represented by Inoceramus irenensis Warren and Stelck, 1958, apparently immigrated into the Western Interior Basin.The Western Interior inoceramids do not allow for direct correlation to chronostratigraphic standard subdivision. The Albian-Cenomanian boundary, as earlier recognized on geochronologic correlations and confirmed, to some extent, based on ammonites, may approximately be located close to the appearance level of the genus Posidonioceramus.  相似文献   

基于误差理论的产状测量精度评定     

卢立吉  王凤艳  王明常  李启源 《世界地质》2016,35(2):567-574

以边坡为研究对象,针对基于罗盘、免棱镜全站仪、激光测距仪、三维激光扫描仪和数字摄影测量工作站的5种产状测量方法,采用误差理论进行产状测量精度评定。研究表明,罗盘产状测量的倾向、倾角中误差分别为±4°和±3°,其精度评定既可以提高对罗盘产状测量精度的认识,也可为其他4种非接触类产状测量方法的精度评定提供验算数据。利用罗盘只能进行高陡边坡下部结构面的产状测量,测量范围有限且高耗低效;非接触类产状测量方法则可以解决人员难以到达的高陡边坡上部结构面的产状测量问题。其中,三维激光扫描和数字近景摄影测量方法可以获取边坡岩体大量随机结构面上的产状信息,为基于随机动力学的边坡稳定性评价提供重要的基础数据。  相似文献   

卫星摄影姿态测定系统低频误差补偿   总被引：1，自引：0，他引：1  

王任享  王建荣  胡莘 《测绘学报》2016,45(2):127-130

姿态测定系统不仅存在高频误差,还存在与卫星轨道纬度及时间有关的低频误差,严重影响无地面控制点测量精度。本文分析了产生低频误差的因素及相关解决措施,并在天绘一号(TH-1)卫星工程中,利用光束法平差实现低频误差的自动检测与补偿处理,消除低频误差对定位精度的影响,最后进行了试验验证。试验结果表明:低频误差补偿技术,很好地解决了无地面控制定位系统误差问题,为实现天绘一号卫星全球定位精度的一致性发挥了重要作用。  相似文献