查询词典 trilateration survey

The method of obtaining time delay parameters with the reverse access channel is discussed. The modified algorithms of classic correlation methods of TOA estimation are proposed. Noncoherently combining algorithm and group coherent combining algorithm are given. They decrease the computational complexity and are more suitable for implementations in practical systems. The leading edge detection algorithm is proposed to mitigate the effect of multipath in TOA estimation. Then the secondary search method is proposed, it can solve the matching issue of PN code in CDMA systems. The location algorithms based on LS are discussed; include circular trilateration with LS, hyperbolic trilateration with reference differencing, hyperbolic trilateration with sequential differencing and circular trilateration with TOA differences. The design and implementation of wireless location system based on TOA/TDOA in CDMA2000 systems are given. The location process is discussed, and the hardware and software implementation of TOA estimation are given. Finally, the wireless location system which uses TOA estimation and LS location algorithms above is tested in the real environment.

文中讨论了采用CDMA2000反向链路中的接入信道来获取时延的方法和过程；对TOA估计的传统的相关法进行了改进，提出了非相干合并相关法和分组合并相关法，减少了基于相关的时延估计算法的运算量，提高了算法的实用性，对算法进行了仿真和性能分析；采用边缘检测技术有效减少了TOA参数估计中的多径干扰，提高了时延参数估计的准确度；提出了一种TOA估计的二次搜索法，解决了多个定位测量单元同时进行TOA估计的PN码匹配问题，进一步了提高TOA估计的精度；在采用时延值的定位算法中引入了基于LS的圆周法、基于参考差的双曲线法、基于相邻差的双曲线法和基于TDOA的圆周法，讨论了各算法的应用条件，进行了算法性能的仿真分析；给出了CDMA2000系统中的TOA/TDOA的无线定位的系统方案和实现流程，并对TOA值估计算法进行了软硬件实现，还对采用TOA估计算法、LS定位算法和定位系统设计方案实现的定位系统的进行了现场定位性能测试。

In this thesis, we proposed a robust trilateration method to estimate Path Loss Exponent which stands for the signal attenuate rate for each reference node to target path by using two different frequency signals and the trilateration method. Then we used every PLE to calculate the corresponding distance and performed the trilateration positioning task using these distances. We also ran two simulations to evaluate our proposed method.

但另一方面，即使在同一空间中，却因为存在著许多变数而导致各个不同的路径都拥有自己的路径衰减指数，所以此篇论文我们提出先利用两个不同频率的讯号测得参考点到目标上的路径衰减指数后，再利用此数值做此路径的距离推导，最后再藉由三点定位法做出目标的定位。

This paper introduces the outline of inside tunnel survey,and expounds the survey control in tunneling works from aspects of the construction traverse survey,midline layout survey,midline detection and tolerance,elevation control survey,vertical section survey and cross section survey,and breakthrough survey,etc.

介绍了洞内测量纲要，从施工导线测量、中线施工放样、中线检测与限差、高程控制测量、纵断面测量和横断面测量、贯通测量等方面阐述了隧洞工程测量控制。

Trilateration survey; trilateration

测量三边网的边长，以确定网中各点平面位置的技术与方法。

Province, Shijiazhuang, Baoding have been involved in two rounds of 61 cities nationwide survey and synthesis of MSM epidemic prevention and control work, 4-6 months of this year the third round of the survey will be carried out; the rest of the city of nine work-site investigations and Shijiazhuang, Baoding, the third round of the survey the same time, also in accordance with the national program of 61 pilot cities, the survey used a snowball method, sample size of 300 people, mainly MSM population survey of AIDS, syphilis, hepatitis C infection; Shijiazhuang, Baoding, the completion of the third round of the national survey At the same time, will also focus on the MSM population in rural areas of the outbreak investigation; in July 2009, municipalities to carry out data entry, upload, analysis and summary.

我省石家庄、保定已参与两轮全国61个城市MSM疫情调查与综合防治工作，在今年4-6月份将开展第三轮调查；其余9市的现场调查工作与石家庄、保定的第三轮调查同步进行，同样按照国家61个试点城市方案、采用滚雪球法调查，样本量均为300人份，主要调查MSM人群艾滋病、梅毒、丙肝的感染情况；石家庄、保定在完成全国第三轮调查的同时，还将侧重于农村地区的MSM人群的疫情调查；2009年7月，各市进行数据录入、上传、分析和汇总。

In this study, we analyze the limitation of trilateration based approaches and propose a novel approach which inherits the simplicity and efficiency of trilateration, while at the same time improves the performance by identifying more localizable nodes.

本文的研究中分析了基于三边测量技术的局限性，提出了继承三边测量技术的简单性和有效性的一个新奇的方法，改方法能在提高定位性能的同时增加即可定位的节点。

RSSI-based location is a hotspot in nowadays. This paper presents RSSI-based triangle and centroid location algorithm and trilateration algorithm, and analyses the average positioning error produced by this two methods. Simulation experiments prove that triangle and centroid location algorithm can obviously improve the location accuracy compared to trilateration algorithm.

基于RSSI的定位技术是现阶段研究的热点，本文提出了基于RSSI的三角形质心定位算法和三边测量法，并对两种算法所产生的平均定位误差进行仿真分析，仿真结果表明基于RSSI的三角形质心定位算法比基于RSSI的三边测量定位算法的定位精度有较大提高。

The background survey and tracking survey of artificial reef area in Chenghai Laiwu were carried out before and after reefing in 2003 and 2007, respectively. The results indicated that after the deployment of artificial reefs, the biomass density of fishery resources increased by 25.63 times, which were much higher than before. The resources species was much more abundant; total number increased from 23 to 41, which increased by 0.78 times. The crab resources sharply increased by 1.75 times after artificial reef were deployed. Harpodon nehereus and Portunus sanguinolentus , which did not appeared in background survey, now became the dominant species in tracking survey. There were high diversity indexes in artificial reefs area and control area in tracking survey. In conclusion, the results indicated that the fish-aggregating effect of artificial reef site has improved a lot, and the community structure and the habitat environment have been significantly improved.

摘 要：2003和2007年分别对澄海莱芜人工鱼礁区进行了投礁前的本底调查和投礁后的跟踪调查，结果表明，投礁后礁区海域游泳生物的资源密度明显比投礁前高，增加了25.63倍；礁区海域各类资源种类均比投礁前丰富，总种数由投礁前的23种增加至41种，比投礁前增加了0.78倍，其中，蟹类种数增加最多，增加了1.75倍；在本底调查中没有出现的经济种类龙头鱼 Harpodon nehereus 和红星梭子蟹 Portunus sanguinolentus 在跟踪调查中已成为主要优势种；Shannon-Wienver多样性指数在礁区和对比区均比投礁前有所增加。

First, the survey process, including the sampling procedure and design of the survey questionnaire, increases the risk that the survey will collect nonrepresentative data from the survey population, thereby limiting the overall representativeness of the resulting survey data.

首先，调查过程，包括抽样程序和设计的调查问卷，增加了风险，这项调查将收集数据nonrepresentative从调查的人口，从而限制了整体的代表性，由此产生的调查数据。

It introduces Survey control network pattern choice and its arrangement, cross river water level datum survey, single shaft orientation during pipe jacking for cross river cable tunnel at FuXing Road East, as well as design and application of Xiong Ying pipe jacking automatic survey guiding system applied in vertical curvature pipe jacking survey.

提 要：本文介绍了复兴东路220kV电缆越江隧道顶管工程施工测量中控制网的选形与布设、跨江水准测量、单井定向，以及雄鹰顶管自动测量引导系统在竖曲线顶管测量中的设计与应用，对类似作业及相应的工业软件开发极具参考价值。

Finally it offers the analysis of the fault-tolerance system as well as its test verification.

这样，运行于空间环境中的系统的设计目标就是在保证系统实时性

However, it is still difficult to find out the real reason of the increase of the keratinized gingiva during the orthodontic extrusion whether it is due to the proliferation of the gingival tissue or to its elastic nature, that is because the proliferation of the fibroblasts as well as the connective tissue changes in volume and the intra-fibers spaces were all immeasurable in most of the studies.

然而，仍然难以找到真正的原因增加的角化牙龈在正畸挤压它是否是由于扩散的牙龈组织或其弹性性质，这是因为增殖的成纤维细胞以及作为结缔组织的变化量和内部纤维空格都是不可估量的，大多数的研究。