已知数据误差对GPS定位成果的影响分析

GPS具有精度高定位、观测快速、操作简便、全天候作业等特点,已被广泛地应用于大地测量和工程测量中。在GPS坐标转换中,当已知点存在较大误差或含有粗差时,将严重影响GPS最终成果的可靠性。为了探讨GPS定位成果坐标转换后的精度,以南水北调中线工程中的某段数据为例,通过逐渐改变已知数据的误差,研究了已知点的平面误差变化对GPS定位成果坐标转换的影响规律,这对于实践中GPS数据处理的应用具有重要的参考价值,可为选择合理的已知数据提供借鉴。     

GPS定位存在的误差分析

GPS系统的定位误差直接影响着GPS定位精度，按其产生的来源、性质及时系统的影响等进行了初步分析，以便采取相应的措施消除或削弱它们对测量结果的影响。     

浅析GPS系统的误差来源

GPS系统的定位误差直接影响GPS定位精度，本文按其产生的来源、性质及对系统的彰响等进行了介绍和初步分析，并提出了相应的措施以便消除或削弱它们对测量结果的影响。     

GPS-RTK技术在铁路定测中的应用

RTK定位技术是以载波相位观测值为根据的实时差分GPS定位技术，实施动态测量。在RTK作业模式下，基准站通过数据链将其观测值和测站坐标信息一起传送给流动站。流动站不仅通过数据链接收来自基准站的数据，还要采集GPS观测数据，并在系统内组成差分观测值进行实时处理，同时通过输入的相应的坐标转换参数和投影参数，实时得到流动站的三维坐标及精度。     

GPS测量中的坐标系统及坐标转换

本文通过对GPS测量中不同坐标系统的分析,阐明了不同坐标系统之间数据转换的本质.笔者结合生产中使用的GPS设备,阐述WGS-84坐标系向地方坐标系转换的一般过程和注意事项.     

浅谈GPS技术在矿区地面测量中的应用

一、GPS系统概述 1．全球定位系统GPS，该系统是由美国军方研发的卫星导航系统，能为用户提供三维坐标、速度和时间，对常规测量而言，主要采用GPS的相对测地定位功能，即只获取地面点的三维坐标。     

GPS水下地形测量误差分析及改正

从GPS水下地形测量出发,粗略地分析研究了GPS的误差来源以及误差对水下地下测量的影响,同时,提出了相应的改正办法.     

GPS测量的误差分析

针对当前GPS定位技术的发展及其应用的普及，特别是在大地测量、工程测量、工程变形监测、地理信息数据采集和更新等测绘学科的应用前景，本人简要介绍了GPS测量误差的来源及其减弱误差的方法。     

利用差分技术提高手持GPS的定位精度

手持式GPS具有操作简便,观测的时间短,测站间无须通视,可提供三维坐标等特点,其观测的数据精度能够应用于诸多领域.但还可以利用差分数据处理将手持式GPS的精度提高.满足人们更多的需要.本文运用多次平均值测量、位置差分校正的方法,使轻便、价廉的GPS定位仪平面定位误差从数米级降低到1m左右,达到亚米级精度,为用户准确地提供位置信息,及一些导航引导信息.     

浅谈GPS在工程测量中的应用

在建筑的建造过程中，工程测量是十分关键的一环，也是确保测量数据准确的基本步骤。采用GPS技术来进行建筑物建造中的工程测量，并对于这种传递进行定位，有利于满足工程建筑迅捷、优质的质量要求，使得建筑物的施工活动符合指标。本文结合具体的建筑工程案例，分析了GPS技术在建筑物工程测量方面的定位作用。实验和研究结论显示：在建筑物工程测量中，采用GPS技术方式来定位，能够收到良好的效果。     

石漠化防治:贵州新农村建设的难点和重点

喀斯特石漠化是贵州省农民生存生产环境的最大威胁，是贵州省“三农”问题产生的主要根源。本文认为石漠化防治既是贵州省社会主义新农村建设的难点所在，也是贵州省社会主义新农村建设的重点和关键。     

The research of Chinese karst ecological hydrology

1. Introduction The area of carbonate rocks protruding through the soil level in China is 9.07*105km2. According to the area of carbonate rocks stratum protruding through the soil level, it is 2.06*106km2. With the buried carbonate rocks stratum of the different depths, its total area can reach 3.443*106km2, ap- proximately accounting for 1/3 of the national terri- torial area. Chinese carbonate rock is mainly distributed to the south of the latitude belt of Tianshan Mountain – Yinshan Moun…     

贵州土地石漠化与"三农"问题的经济学分析

西南地区石漠化已经成为我国的两大生态灾难之一,而贵州省又处于我国西南部石漠化地区的中心。严重的土地石漠化已经使贵州省的一部分农民丧失了基本的生产和生存条件,是贵州农村贫困的最直接、最根本原因。因此,土地石漠化是贵州省“三农”问题产生的主要根源,加快土地石漠化综合治理是解决贵州省“三农”问题的根本途径。     

What to stabilize in the open economy*

We consider the question how “best” to maintain price‐level stability in an open economy, and evaluate three possible policy choices: (a) a constant money growth rate rule; (b) a fixed exchange rate; and (c) a policy of explicit commitment to a price‐level target. In each case we assume that policy is conducted by injecting reserves into or withdrawing reserves from the “banking system.” In evaluating the three regimes, we adopt the criterion that the “best” policy should leave the least scope for indeterminacy and “excessive” economic volatility. In a steady‐state equilibrium, the choice of regime is largely irrelevant; any steady‐state equilibrium under one regime can be duplicated by an appropriate choice of the “control” variable under any other regime. However, we show that the sets of equilibria under the three regimes are dramatically different. When all countries follow the policy of fixing a constant rate of money growth, there are no equilibria displaying endogenously arising volatility and there is no indeterminacy of equilibrium. Under a regime of fixed exchange rates, indeterminacies and endogenously arising fluctuations are impossible if and only if the country with the low “reserve‐to‐deposit” ratio is charged with maintaining the fixed rate. Finally, when one country targets the time path of its price level, under very weak conditions, there will be indeterminacy of equilibrium and endogenously arising volatility driven by expectations.     

The adoption of photovoltaic systems in Wiesbaden,Germany

The purpose of this study is to investigate factors that determine the adoption of photovoltaic (PV) systems. Our case study of the city of Wiesbaden, Germany, is based on a geocoded data set of the grid-connected PV systems set up through 2009. We aim to determine whether the decision to install can be explained by peer effects measured by preexisting installations in the vicinity, i.e. the installed base which is determined for each decision-maker individually. We employ a binary panel logit model and control for spatial variations in buying power and population density. Our analysis reveals a significantly positive influence of previously installed systems located nearby on the decision to install a PV system.     

会计准则性质的系统认识

研究会计准则的性质,对于正确制定和运用会计准则,充分发挥会计准则的作用具有十分重要的意义。探讨会计准则的性质应当以系统论为指导,全面、准确认识会计准则的性质。从系统论的观点来看,会计准则既是一种技术规范,也是一种社会规范,还是一种制度和公共物品。     

Seemingly unrelated regressions with spatial error components

This article considers various estimators using panel data seemingly unrelated regressions (SUR) with spatial error correlation. The true data generating process (DGP) is assumed to be SUR with spatial error of the autoregressive or moving average type. Moreover, the remainder term of the spatial process is assumed to follow an error component structure. Both maximum likelihood (ML) and generalized moments (GM) methods of estimation are used. Using Monte Carlo experiments, we check the performance of these estimators and their forecasts under misspecification of the spatial error process, various spatial weight matrices, and heterogeneous versus homogeneous panel data models.     

Income effects and indeterminacy in a calibrated one-sector growth model

This note analyzes how the indeterminacy of competitive equilibrium in one-sector growth models depends on the magnitude of the households' income effect on the demand for leisure. Since I am interested in quantitatively characterizing regions of indeterminacy, I use the Jaimovich and Rebelo [N. Jaimovich, S. Rebelo, Can news about the future drive the business cycle? Mimeo, Northwestern University, 2007] preferences that span a wide range of income effect values. I find that indeterminacy can occur for levels of aggregate-returns-to-scale that are well within recent empirical estimates. For these regions of indeterminacy, the model, when driven solely by sunspot shocks, generates second-moment properties that are consistent with the U.S. data at the business cycle frequency.     

近20年内蒙古西乌珠穆沁草原景观结构变化浅析

借助景观生态学方法及遥感和地理信息系统等技术,编制草原景观类型图,并利用专业景观分析软件FRAGSTATS对内蒙古西乌珠穆沁草原景观的连通性、异质性等进行定量分析。结果表明：西乌珠穆沁草原景观空间结构发生了一定程度的变化,土地沙化退化趋势明显,人工景观比例增加,但总体相对稳定,草地景观占整个景观面积的86%以上。随着人为活动干扰加剧和气候环境变化,景观整体的破碎度加剧,连通性降低,景观的分布更加均匀化,生态系统向退化方向发展。     

Panel data inference under spatial dependence

This paper focuses on inference based on the standard panel data estimators of a one-way error component regression model when the true specification is a spatial error component model. Among the estimators considered, are pooled OLS, random and fixed effects, maximum likelihood under normality, etc. The spatial effects capture the cross-section dependence, and the usual panel data estimators ignore this dependence. Two popular forms of spatial autocorrelation are considered, namely, spatial autoregressive random effects (SAR-RE) and spatial moving average random effects (SMA-RE). We show that when the spatial coefficients are large, test of hypothesis based on the standard panel data estimators that ignore spatial dependence can lead to misleading inference.