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1.
C++ and Java code for recursion formulas in mathematical geodesy 总被引:2,自引:0,他引:2
Klaus Hehl 《GPS Solutions》2005,9(1):51-58
2.
A global positioning system (GPS)-based online control and alarm system (GOCA) for monitoring of three-dimensional movements
has been developed at the Karlsruhe University of Technology. The GOCA hardware consists of an array of GPS sensors and communication
units to be placed in the monitoring area. The hardware-dependent control software communicates with the GPS sensors and provides
the GPS baseline data and covariance information to the GOCA deformation analysis software. The GOCA center, which comprises
both the control software and the GOCA software, may be linked – for example, over a long distance – to another personal computer
(PC) that serves as a remote control station. GOCA is able to provide the full capabilities of classical deformation analysis
online (with stations grouped into stable points and moving object points). Both types of points may be occupied either continuously
or over short periods at different times. The object points are determined with respect to the stable points. A network adjustment
is performed for each interval of data collection, and the coordinate and covariance information may optionally be transformed
into a specific reference system (e. g., the building system). Unstable reference points are to be detected by statistical
tests. The estimated object point time series are filtered with respect to gross errors using robust estimation techniques.
Online filters are used to smooth the time series data of critical displacements and to predict other deformation functions.
The time series data, as well as prediction results, are displayed graphically for each object point. An example concerning
the online monitoring of a slag heap in a coal-mining area is included. ? 2000 John Wiley & Sons, Inc. 相似文献
3.
Architectures of Software GPS Receivers 总被引:6,自引:0,他引:6
There are various applications in which a Global Positioning System (GPS) sensor only down-converts and digitizes the received
GPS signal and sends the digitized data to a processor, where the processor software performs all the correlation, search/track
operations, navigation solution, and so on. Among the applications are military and commercial ones (e. g., GPS(Communication
handheld sets, people tracking systems).
A major problem with the Software GPS Receiver is the large computing resources required for correlation or acquisition of
the GPS signal. In this article, several possible approaches for reducing computing resources will be introduced and analyzed.
It will be shown that the performance of the GPS software design strongly depends on the features of the computer hardware.
Implementations will be described on the TMS320C6201 processor and the Pentium II.
Experimental results will be demonstrated by processing of real GPS signals. A complete 16-channel GPS receiver was implemented
on the single TMS320C6201 processor in real-time mode and on the Pentium II processor with a duty cycle of about 50%. ? 2000
John Wiley & Sons, Inc. 相似文献
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5.
Applied Research Laboratories, The University of Texas at Austin (ARL:UT) has established a cross platform open source software
project called the GPSTk or the GPS Toolkit. The GPSTk consists of a library and collection of applications that support GPS
research, analysis, and development. The code is released under the terms of the Lesser GNU Public License. The GPSTk supports
a broad range of functionality. This includes reading and writing observations in standard formats, such as RINEX, BINEX,
and SP3, ephemeris evaluation, position determination, receiver autonomous integrity monitoring (RAIM), atmospheric delay
modeling, cycle slip detection and correction, and P-code generation. The GPSTk provides the core set of functionality that
is used for GPS research and development at ARL:UT. ARL:UT has been involved with satellite navigation since Transit (the
precursor to GPS) in the 1960s and is currently conducting research in a wide variety of GPS-related fields, including precise
surveys, monitor station networks, and ionospheric studies. The GPSTk is a community-wide resource for all users of GPS and
GNSS technology. Participation is welcomed in all areas including: bug reports, new algorithms, suggestions for improvement,
and contributions of additional functionality or applications. ARL:UT continually improves the library, shepherds community
participation, and is committed to the project’s development and maintenance.
The GPS Toolbox is a column dedicated to highlighting algorithms and source code utilized by GPS Engineers and scientists.
If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail
it to us at gps-toolbox@ngs.noaa.gov. To comment on any of the source code discussed here, or to download source code, visit
our website at . This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic
Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada. 相似文献
6.
Unlike the conventional hardware approaches to GPS base band signal processing, a software GPS receiver is extremely flexible
as it comes with all the associated advantages of a software solution. With a software solution, the improvements of silicon
technology can be easily translated into better performance at smaller form factors and lower power consumption, without a
redesign and/or change to the ASIC. A general purpose Digital Signal Processor (DSP) can be used effectively for GPS signal
processing. The memory and speed resources available determine the algorithms and applications that can be effectively implemented
in the receiver. The performance of software GPS receivers will soon be difficult to be surpassed by the hardware counterparts,
as high-performance processors become available at low cost. ? 2000 John Wiley & Sons, Inc. 相似文献
7.
MATLAB Tools for viewing GPS velocities and time series 总被引:3,自引:2,他引:1
Over the past decade, many Global Positioning System (GPS) networks have been installed to monitor tectonic motions around the world. Some of these networks contain hundreds of sites spread across active tectonic margins where the differences in velocities across the network can be 50–100 mm/year. For networks that have been running for a number of years, the uncertainty in the velocity estimates can be less than 1 mm/year. In some cases the vertical motions can also be significant and of importance. Often, the time series of the motions of the GPS sites show complex non-linear behavior, and in all cases the statistical model of the time series is more complex than simple white noise. In this article, we describe a set of Matlab tools developed for use with the GAMIT/GLOBK GPS data analysis system (King 2002; King and Herring 2002) that allow interactive viewing and manipulation of GPS velocities and time series with a Matlab-based graphical user interface (GUI). The formats of the data files used by the tools are specific to GAMIT/GLOBK, but they are simple ASCII files that can be generated from other file formats. The tools are referred to as GGMatlab.The GPS Toolbox is a column dedicated to highlighting algorithms and source code utilized by GPS Engineers and scientists. If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail it to us at gps-toolbox@ngs.noaa.gov/. To comment on any of the source code discussed here, or to download source code, visit our website at . This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada. For the sidebar, see the Volume 6, Number 4, 2003 issue of the GPS Toolbox column. 相似文献
8.
In this article, Dr. J.F.G. Monico introduces the on-line resources at the website of the UN Office for Outer Space Affairs, including the web-based GPS resources and their technical background information. Its purpose is to inform the reader about the data, software, electronic documents that are available on-line. This article is coordinated by Dr. Jinling Wang, University of New South Wales, Sydney. Comments and suggestions are appreciated (Jinling.Wang@unsw.edu.au). 相似文献
9.
In this article, the architecture of a software Global Positioning System (GPS) receiver is described and an analysis is included
of the performance of a software GPS receiver when tracking the GPS signals in challenging environments. Results are included
that demonstrate the advantage of the software GPS receiver in tracking the GPS signals in low signal-to-noise or jamming
scenarios. Various current and previous applications of the software GPS receiver are also described. ? 2000 John Wiley &
Sons, Inc. 相似文献
10.
GPS technology will face not one but two critical rollover dates over the next eight months. One is the millennium (Y2K) rollover.
The other is the GPS week 1024 rollover also known as the GPS End of the Week (EOW). Each rollover dat has the potential to
cause severe problems in GPS receivers and related software. This article expolres the reasons why these dates are a problem
and describes choices that must be made as to their solution. The paper also describes some verification methods that may
be used to test GPS receivers and software. ? 1999 John Wiley & Sons, Inc. 相似文献
11.
Several hybrid neutral atmosphere delay models have been developed at the University of New Brunswick. In this paper we are
presenting UNB3m_pack, a package with subroutines in FORTRAN and corresponding functions in MatLab which provides neutral
atmospheric information estimated using the UNB3m model. The main goal of UNB3m is to provide reliable predicted neutral atmosphere
delays for users of global navigation satellite systems (GNSS) and other transatmospheric radiometric techniques. Slant neutral
atmosphere delays are the main output of the package, however, it can be used to estimate zenith delays, Niell mapping functions
values, delay rates, mapping function rates, station pressure, temperature, relative humidity and the mean temperature of
water vapor in the atmospheric column. The subroutines work using day of year, latitude, height and elevation angle as input
values. The files of the package have a commented section at the beginning, explaining how the subroutines work and what the
input and output parameters are. The subroutines are self-contained, i.e., they do not need any auxiliary files. The user
has simply to add to his/her software one or more of the available files and call them in the appropriate way.
The GPS Tool Box is a column dedicated to highlighting algorithms and source code utilized by GPS engineers and scientists.
If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail
it to us at gps-toolbox@ngs.noaa.gov. To comment on any of the source code discussed here, or to download source code, visit
our website at . This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic
Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada. 相似文献
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An ActiveX GPS control is presented which can be used to develop software applications with GPS functionality. It translates
the NMEA 0183 interface GPS instructions and triggers event procedures which are used by applications to access the GPS data.
It provides position data in the form of geographic coordinates as well as Universal Transverse Mercator (UTM) projected coordinates.
This control is recommended for the development of general purpose GPS-enabled applications which do not require a high level
of accuracy. A Visual Basic project is also included to demonstrate the use of various features of this control. Finally,
some real-time software applications are discussed which have been developed using this control. These applications include
static point averaging; path tracking; and imagery-based position mapping. 相似文献
14.
分别在精密星历与广播星历下采用TBC 2.8数据处理软件进行C级全球定位系统(GPS)控制网基线解算,并采用GAMIT加载精密星历文件进行基线解算,在COSAGPS软件中进行环闭合差统计及平差计算.针对上述方法得出的数据进行比较,分析TBC软件采用不同星历解算对C级GPS基线解算及网平差成果的影响,研究发现TBC在两种星历下均可进行C级GPS数据解算,但在精密星历下的基线解算精度较高,在工作中可根据实际情况采取恰当的方法作业. 相似文献
15.
随着GPS和传统地面测量技术的发展,两种技术的组合应用常常是适宜的选择。显然,有关GPS网与地面网联合处理的研究在GPS测量技术应用中是重要的。本文对区域GPS网与地面网3维联合平方差方法进行了研究,给出了相应的函数模型,解决了经典3维平差中天文经纬度缺乏和垂直折光差改正两个关键技术问题,此外,为节省计算机存储和运算时间,笔者建议采用变带宽存储法和剖面极小化算法,文章的最后简要介绍了CPSTGD数据处理软件。 相似文献
16.
近年来手持GPS在基层国土资源管理部门的野外调查工作中的需求越来越迫切。利用智能手机GPS的功能配合专业的手机GPS软件可快速高效地实现土地权属确认、长度测算、准确定位等野外调查和监测工作,并且能满足一般精度的测量要求。较之价格高昂的专业GPS,该方法具有费用低廉、操作便捷的特点,非常适合基层国土资源工作人员掌握使用。 相似文献
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18.
GPS和航空影像在现代测量中已成为一种不可或缺的技术手段,如何能更好地利用现有的我们能掌控的技术资源,让它为我们的测量服务呢?在这里我根据以往的工作经验及对GPS手持机处理软件MapSource和Google Earth的使用情况,初步探讨这两种软件的整合及给我们测量工作带来的益处,尚需说明的是本文只是想起到一个抛砖引玉的作用,希望能给大家带来一点有益的思考. 相似文献
19.
Ahmed Elaksher Tarig Ali Franck Kamtchang Christian Wegmann Adalberto Guerrero 《International Journal of Digital Earth》2020,13(5):586-601
ABSTRACTEstablishing reliable elevation differences is imperative for most geoscience and engineering applications. This work has traditionally been accomplished through spirit leveling techniques; however, surveyors have been utilizing satellite positioning systems in measuring height differences for more than a decade. Yet the quality of these heights needs to be evaluated in order to adopt them in different applications. In this article, we present the outcome of an accuracy assessment of height differences obtained with static and RTK surveys. Twenty control points with an average baseline length of 1?km were occupied with dual-frequency GNSS receivers for different time periods. Collected signals were processed using open-source software and verified with an online processing tool. Heights were estimated by processing the GPS and the GLONASS data individually, and combined (i.e. GNSS). Height differences were determined and compared with those measured by spirit levels and corrected through geoid models. Best results were achieved by combining GPS and GLONASS solutions for both static and RTK surveys. Solutions with either GPS or GLONASS satellites were comparable, but in most cases, the GPS solutions performed better. For the static surveys, longer occupation provided much accurate height differences. Inconsistencies among 10 different RTK surveys were minimum for the GPS?+?GLONASS solutions and worst for the GLONASS solutions. The ANOVA, LSD, F, and χ² statistical tests confirmed our findings at the 95% confidence level. 相似文献
20.
The Scripps Orbit and Permanent Array Center (SOPAC) has completed development for the UNAVCO community of first-generation GPS Seamless Archive (GSAC) software. The GSAC is a virtual archive composed of an assembly of agencies and investigators exchanging information about their respective GPS-related data holdings in a well defined, cohesive manner. The superset of this published information is collected and ingested into centralized databases administered currently by two data brokers (Retailers), who make the data available to the public in a seamless manner. There are three user interfaces available: the interactive GSAC Wizard, a command-line Unix-style executable called gsac-client, and a front door HTTP service called the GSAC Retailer Service Interface. Each user interface provides access to the data collections of 6 different GPS archives (GSAC Wholesalers) in North America. Together these archives have published more than 2 million GPS data files pertaining to over 10,000 different geodetic monuments. These datasets are composed in large part of data collected by US scientists and their collaborators over the period 1986 to the present in Western North America and other tectonically active regions around the globe, as well as the holdings of two IGS global data centers. In this article, we describe how the three GSAC user interfaces provide the community a powerful set of tools for seamlessly mining information and collecting data files from a distributed network of GPS archives.The GPS Toolbox is a column dedicated to highlighting algorithms and source code utilized by GPS Engineers and scientists. If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail it to us at gps-toolbox@ngs.noaa.gov. To comment on any of the source code discussed here, or to download source code, visit our website at . This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada. 相似文献