Closed-form solution of P4P or the three-dimensional resection problem in terms of Möbius barycentric coordinates     

E. W. Grafarend  J. Shan 《Journal of Geodesy》1997,71(4):217-231

 The perspective 4 point (P4P) problem - also called the three-dimensional resection problem - is solved by means of a new algorithm: At first the unknown Cartesian coordinates of the perspective center are computed by means of M?bius barycentric coordinates. Secondly these coordinates are represented in terms of observables, namely space angles in the five-dimensional simplex generated by the unknown point and the four known points. Substitution of M?bius barycentric coordinates leads to the unknown Cartesian coordinates (2.8)–(2.10) of Box 2.2. The unknown distances within the five-dimensional simplex are determined by solving the Grunert equations, namely by forward reduction to one algebraic equation (3.8) of order four and backward linear substitution. Tables 1.–4. contain a numerical example. Finally we give a reference to the solution of the 3 point (P3P) problem, the two-dimensional resection problem, namely to the Ansermet barycentric coordinates initiated by C.F. Gau? (1842), A. Schreiber (1908) and A.␣Ansermet (1910). Received: 05 March 1996; Accepted: 15 October 1996  相似文献   

Closed form solution to the twin P4P or the combined three dimensional resection-intersection problem in terms of Möbius barycentric coordinates     

E. Grafarend  J. Shan 《Journal of Geodesy》1997,71(4):232-239

The twin perspective 4 point (twin P4P) problem – also called the combined three dimensional resection-intersection problem – is the problem of finding the position of a scene object from 4 correspondence points and a scene stereopair. While the perspective centers of the left and right scene image are positioned by means of a double three dimensional resection, the position of the scene object imaged on the left and right photograph is determined by a three dimensional intersection based upon given resected perspective centers. Here we present a new algorithm solving the twin P4P problem by means of M?bius barycentric coordinates. In the first algorithmic step we determine the distances between the perspective centers and the unknown intersected point by solving a linear system of equations. Typically, area elements of the left and right image build up the linear equation system. The second algorithmic step allows for the computation of the M?bius barycentric coordinates of the unknown intersected point which are thirdly converted into three dimensional object space coordinates {X,Y,Z} of the intersected point. Typically, this three-step algorithm based upon M?bius barycentric coordinates takes advantage of the primary double resection problem from which only distances from four correspondence points to the left and right perspective centre are needed. No orientation parameters and no coordinates of the left and right perspective center have to be made available. Received 1 May 1996; Accepted 13 September 1996  相似文献   

Vertical Ozone Profile over Tibet Using Sage I and II Data   总被引：8，自引：0，他引：8  

Zou Han  Gao Yongqi 《大气科学进展》1997,14(4):505-512

ＶｅｒｔｉｃａｌＯｚｏｎｅＰｒｏｆｉｌｅｏｖｅｒＴｉｂｅｔＵｓｉｎｇＳａｇｅＩａｎｄＩＤａｔａ①ＺｏｕＨａｎ（邹捍）ａｎｄＧａｏＹｏｎｇｑｉ（郜永祺）ＩｎｓｔｉｔｕｔｅｏｆＡｔｍｏｓｐｈｅｒｉｃＰｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅ...  相似文献   

帕米尔地区地震活动及震源机制解的分布特征   总被引：2，自引：0，他引：2  

高国基  戈澍漠 《内陆地震》1997,11(4):302-308

帕米尔地区存在一个明显的ＮＥ－ＳＷ向中，深源地震带，中，深源地震震源机制分布具有明显的区域特征，兴都库什地区震源断错以倾滑逆断层为主，Ｔ轴仰角几乎垂直，帕米尔弧形构造东侧分布的地震以走滑性质为主，Ｐ轴仰角接近水平，当深度为１００～２００ｋｍ时在弧形构造南侧形成了一个明显的北东向的正断层分布。中，深源地震主压应力方向随深度增加由ＮＷ向逐渐变为ＮＥ向，主压应力Ｐ轴仰角平缓。  相似文献   

徐淮地区冬小麦产量形成的穗粒结构模式          下载免费PDF全文

高苹  武金岗  陶炳炎  汤志成 《气象》1997,23(1):11-16

依据数学生态学理论，采用非线性密度制约形式，将主要气象条件的影响以指标形式引入模式参数，设计并研究了冬小麦穗粒结构产量模式，从穗粒结构途径研究了产量形成过程。  相似文献   

人工增雪对冬麦冻害的影响   总被引：3，自引：0，他引：3       下载免费PDF全文

高子毅  贾昭茂 《气象》1997,23(9):27-30

自１９７８年以来，在新疆北部沿天山一带对冬季层状云飞机播撒碘化银、干冰等冷云催化剂进行人工增雪作业，对１８个非播云年和１７个播云年的冬麦冻害做了对比，在播云期内冬小麦年平均冻害面积减少８０％以上。对３个主要因素（麦种改良、冬季气温升高和人工增雪）进行了分析，结果表明，人工播云是一个主要的因素。  相似文献   

EFFECTS OF TROPOPAUSE AND POTENTIAL VORTICITY ANOMALY ON FRONTOGENESIS^*          下载免费PDF全文

Hou Dingchen  Gao Xuehao  Zhuang Xiaolan  Zhang Yong 《Acta Meteorologica Sinica》1997,11(4):446-459

A two-dimensional,semi-geostrophic numerical model incorporating the tropopause and stratosphere is used to investigate the effects of a positive potential vorticity anomaly and latent heat release on the frontogenetic process and the structure of the resulting frontal zone.It is demonstrated that(1) the inclusion of tropopause and stratosphere significantly changes the frontal structure only in the upper levels;(2) a clearly defined quasi-equivalent barotropic structure and a region of upward motion of finite width appear when a positive potential vorticity anomaly exists on the warm side of the maximum baroclinity in the lower troposphere,especially when it is located on the south edge of the baroclinic zone;(3) the above mentioned structure deteriorates as the frontogenesis proceeds in a dry atmosphere but can be maintained in a moist frontogenetic process with condensational heating;(4) the combination of a positive potential vorticity anomaly and the latent heat release is able to accelerate the frontogenesis significantly with the time needed to form an intense frontal zone reduced to less than 15 h.The results have significant theoretical importance in understanding the complex nature of frontal structure and frontogenesis,especially in understanding the dynamic structure of the subtropical frontal zone observed during early summer over East Asia.  相似文献   

地下气体运移变化的物理化学机制研究   总被引：1，自引：1，他引：1       下载免费PDF全文

高清武 《地震地质》1997,19(1):54-58

在河北省怀来县后郝窑地区，对地下气体运移变化的影响因素进行了野外模拟实验研究。选择３个试验点，对地下气体的扩散作用，物理化学影响因素及水压效应等进行了模拟实验，主要研究Ｈ２，ＣＯ２气体运移变化机制。实验研究表明，Ｈ２，ＣＯ２气体运移变化机制不尽相同，水压效应对Ｈ２，ＣＯ２等地下气体运移影响相当明显  相似文献   

寻找相似天气过程的一种数学模型   总被引：1，自引：0，他引：1       下载免费PDF全文

刘景涛  高涛 《应用气象学报》1997,8(1):78-84

该文介绍了一种寻找相似天气过程的数学模型，利用Saaty论述的方法[1]构造判别矩阵进行判别，从而计算出相似排序及相似度。该方法在3年多的预报业务中应用，效果良好。  相似文献   

桩端沉降测量对试桩成果分析的意义     

过培鑫  高倚山 《上海国土资源》1997,(4):1-7

桩端沉降测量和试桩资料的分析结果表明,桩在传递上部荷载与地基土之间产生的应力应变过程,表现为桩的弹性杆件和地基土的弹—塑性变形特征。从而对受荷桩,尤其是长柱和超长桩的应力应变特征有了更切合实际的认识。  相似文献