DOCSLIB.ORG

Standards and Specifications for Geodetic Control .Networks

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Standards and Specifications for Geodetic Control .Networks ' ,//--:,. 1· I �'--/' _,..)', Standards and Specifications for Geodetic Control .Networks ···:=· Federal Geodetic Control Committee Rear Adm. John D. Bossler, Chairman Rockville, Maryland September 1984 FGCC Standards� 1and Specifications for Geodetic Control Networks Federal Geodetic Control Committee John D. Bossler, Chairman September 1984 For information write: Chairman Federal Geodetic Control Coinmittee 6001 Executive Boulevard Rockville, Maryland 20852 For sale by the National GeodeticInformation Branch (N/CG17x2), NOAA, Rockville, MD 20852 j ( , Libraryof CongressCataloging in PublicationData United States. Federal Geodetic Control Committee. Standard and specificationsfor geodetic control networks. Replaces both "Classification, standards .of accuracy, and general specifications of ieodetic control surveys," issued February 1974 and "Specifications to support classification, standards of accuracy, and general specifications of geodetic contrcii surveys," revised June 1980 Pref. c� "September 1984." ( 1. Geodesy-Standards-United States. I. Bossler, John D. II. Title. QB296.U89U5 1984 526.3'3 84-600257 ii Preface This single publication is designed to replace both "Classification, Standards of Accuracy and General Specifications of Geodetic Control Surveys," issued February 1974, and "Specifications to Support Classification, Standards of Accuracy, and General Specifications of Geodetic Control Sur­ veys," issued June 1980. Because requirements and methods for acquisition of geodetic control are changing rapidly, this publication is being released in loose-leaf format so that it can be updated more conveniently and efficiently. Recipients of this publication wishing to receive updated information should complete and mail the form below. Comments on the contents and format of the publication are welcomed and should be addressed to: FGCC Secretariat, Code N/CG1x5 National Geodetic Survey, NOAA , Rockville,Maryland 20852 (Detachand mailto: National GeodeticInf onnation Branch, code N/CG17x2,NOAA, Rockville, Maryland20852) Please inform me of updated information for "Standards and Specifications for Geodetic Control c�'· Networks." Name: ---------------------------------- Address: --------------------------------- D Check here if address given is a private residence. (signature) (date) iii Contents Preface . .. .. ............... .. .... .... ....... .. .... ........................... ........... .. .. .................................. ................... .. iii 1. Introduction.............................................................................................................................. 1-1 2 Standards .................................................................................. · .... ... ... .. ........ ..................... ... 2-1 2.1 Horizontal control network standards ................................. ........................................... 2-1 2.2 Vertical control network standards ................................................................................ 2-2 2.3 Gravity control network standards ................................................................................. 2-3 ,,:-; 3. Specifications....................................................................................................... .................... 3-1 3.1 Introduction .................................................................................................................. 3-1 3.2 Triangulation............................................................................................ .................... 3-1 3.3 Traverse ....................................................................................................................... 3-3 3.4 Inertial surveying ......................................................................................................... 3-5 3.5 Geodetic leveling ........................................................................................................... 3-6 3.6 Photogrammetry.................................................................. : ....................................... 3-8 3.7 Satellite Doppler positioning.................................................................... ...................... 3-9 3.8 Absolute gravimetry................................................ ..................................................... 3-12 3.9 Relative gravimetry........................ : .............................................................................. 3-13- 4. Infonnation.... .............. ·.......................................................................................................... 4-1 5. References ................................................................................................................................ 5-1 Appendix A. Governmentalauthority ................... , ........................................... ,............................... A-1 A.I Authority..................................................................................................................... A-1 A.2 References ................................................................................................................... A-1 Appendix B. Variance factor estimation........................................................................................... B-1 B.1 Introduction..... ...... ...................................... ............................................ ............. ........ B-1 B.2 Global variance factor estimation.................................................................................. B-2 B.3 Local variance factor estimation .......�.............................. ............................................. B-2 B.4 Iterated almost unbiased estimation .............................................................................. B-3 B.5 References.................................................................................................................... B-4 Appendix C. Procedures forsubm itting data to theNational GeodeticSurvey ................................ C-1 V ,!) (-(J 1. Introduction The Government of the United States makes nation­ vertical standards are defined in reasonable conformance wide surveys, maps, and charts of various kinds. These are with past practice. The recent development of highly necessary to support the conduct of public business at all accurate absolute gravity instrumentation now allows a levels of government, for planning and carrying out nationai. gravity reference standard. In the section on "Standards," and local projects, the development and utilization of the classification standards for each of the control net­ natural resources, national defense, land management, works are described, sample computations performed, and monitoring crustal motion. Requirements for geo­ and monumentation requirements given. detic control surveys are most critical where intense devel­ Control networks can be produced only by making very opment is taking place, particularly offshore areas, where accurate measurements which are referred to identifiable surveys are used in the exploration and development of control points. The combination of survey design, instru­ natural resources, and in delineation of state and interna­ mentation, calibration procedures, observational techniques, tional boundaries. and data reduction methods is known as a measurement State and local governments and industry regularly system. The section on "Specifications" describes impor­ cooperate in various parts of the total surveying and tant components and states permissible tolerances for a mapping program. In surveying and mapping large areas: variety of measurement systems. it is first necessary to establish frameworks·of horizontal, Clearly, the control networks would be of little use if vertical, and gravity control. These provide a common the datum values were not published. The section entitled basis forall surveying and mapping operations to ensure a "Information" describes the various products and for­ coherent product. A reference system, or datum, is the set mats of available geodeticdata. of numerical quantities that serves as a common basis. Upon request, the National Geodetic Survey will accept Three National Geodetic Control Networks have been data submitted in the correct formats with the proper created by the Government to provide the datums. It is supporting documentation (appendix C) for incorpora­ the responsibility of the National Geodetic Survey (NGS) to tion into the national networks. When a survey is submit­ actively maintain the National Geodetic Control Net­ ted for inclusion into the national networks, the survey works (appendix A). measurements are processed in a quality control proce­ These control networks consist of stable, identifiable dure that leads to their classification of accuracy and points tied together by extremely accurate observations. storage in the National Geodetic Survey data base. To From these observations, datum values (coordinates or fully explain the process we shall trace a survey from the gravity) are computed and published. These datum values planning stage to admission into the data base. This example provide the common basis that is so important to survey­ will provide an overview of the standards and specifica­ ing and mapping activities. tions, and how they work together. As stated, the United States maintains three control The user should first compare the distribution and networks. A horizontal network provides geodetic lati­
Load more

Recommended publications
  • Maintaining Geodetic Control for California
    Maintaining California's Geodetic Control System Strategic Assessment Version 1.0 Approved by the California GIS Council: December 14, 2017 Prepared by the California GIS Council's Geodetic Control Work Group Maintaining California's Geodetic Control System Strategic Assessment Geodetic Control Work Group Members CHAIR: Scott P. Martin, PLS – California Department of Transportation Landon Blake, PLS – Hawkins and Associates Engineering John Canas, PLS – California Spatial Reference Center Tom Dougherty, PLS – City of Fremont Kristin Hart, GISP – Padre Associates, Inc. Justin Height, PLS – Guida Surveying Ryan Hunsicker, PLS – GISP – County of San Bernardino Bruce Joffe, GISP – GIS Consultant Neil King, PLS – King and Associates Michael McGee, PLS – Geodetic Consultant Ric Moore, PLS – Public sector Reg Parks, LSIT – Santa Rosa Junior College Mark S. Turner, PLS – California Department of Transportation PAST CHAIR: Marti Ikehara – National Geodetic Survey, California Geodetic Advisor, Retired Acknowledgement The Work Group would like to thank the geospatial professionals who provided peer review of this document. Their valued input was critical to the finalization for delivery to the California GIS Council. Disclaimer Statement The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. This publication does not constitute a standard, specification or regulation. This report does not constitute an endorsement by any entity, employer or department of any product
    [Show full text]
  • Evaluation of the Accuracy of the New Primary Precise Geodetic Network in Korea
    Earth Planets Space, 50, 629–634, 1998 Evaluation of the accuracy of the new Primary Precise Geodetic Network in Korea Jae-Hwa Choi Department of Civil Engineering, Sungkyunkwan University, Korea (Received August 25, 1997; Revised April 23, 1998; Accepted May 21, 1998) Accuracy of the Primary Precise Geodetic Network (PPGN) established during the period of 1975–1994 in Korea is investigated through an analysis of residual from free network adjustment. The PPGN, composed of 1155 points with mean side-length of 11 km, was surveyed by EDM trilateration to revise old triangulation network established in 1910 s. A-posteriori standard deviation of unit weight is 3.8 × 10–6 of the observed length. Most of the estimated error ellipses of horizontal coordinates are nearly circular with a radius <5 cm except those in the marginal part of the network. Mean error of the adjusted coordinates was ±4.5 cm, a value good enough for a geodetic control network of current standard, and as the reference for future crustal deformation studies. 1. Introduction To keep consistency with the old coordinates system, the Geodetic control network not only provides a basic PPGN was adjusted in the way that its official coordinates framework for the survey of nation-wide topographic map, are same as the old ones. Unfortunately, original records of cadastral and civil engineering surveys, but also contributes the old survey are lost during the Korean war, and we only to geodynamics. Establishment of nationwide geodetic have a set of coordinates of triangulation points now. Hence, network in the Korean peninsula was carried out in 1910 s.
    [Show full text]
  • FDM 9-20 Spatial Reference Systems
    Facilities Development Manual Wisconsin Department of Transportation Chapter 9 Surveying and Mapping Section 20 Spatial Reference Systems FDM 9-20-1 General February 28, 2001 The discipline of surveying consists of determining or establishing relative positions of points above, on, or beneath the surface of the earth. In Wisconsin, there are two primary spatial reference systems for defining the location of a point: - The U.S. Public Land Survey System (PLSS). - The National Spatial Reference System (NSRS). The PLSS is based on a system of townships, ranges, and sections (see FDM 9-20-5). The PLSS provides the basis for almost all legal descriptions of land. The NSRS, which includes the former National Geodetic Reference System (NGRS), is a mathematical reference system (see FDM 9-20-10). The NSRS consists of precisely measured networks of geodetic control that support accurate mapping over large areas. To understand the roles of these reference systems, it is important to recognize that the PLSS was designed for land ownership purposes but not for accurate mapping, and the NSRS was designed for geodetic surveying and mapping but not for land ownership documentation. Since accurate property maps are becoming essential with digital-based ownership documents, it is important that there be a substantial link between the two reference systems. Methods are needed to utilize the spatial characteristics of the NSRS when addressing the location of landmarks. Fortunately, recent technological developments such as the Global Positioning System (GPS), electronic total station survey instruments, and computer aided drafting (CAD) now make the task of using the PLSS and NSRS together more efficient, economical, and practical.
    [Show full text]
  • China National Report on Geodesy
    2015-2018 China National Report on Geodesy For The 27th IUGG General Assembly Montréal, Québec, Canada, July 8-18, 2019 Prepared by Chinese National Committee for International Association of Geodesy (CNC-IAG) June 25 2019 Contents Preface............................................................................................................................................... 1 1. Construction and Service of modern geodetic datum and reference frame in China ................ 2 1.1 Introduction ................................................................................................................... 2 1.2 Construction of Modern National surveying and mapping datum project .................... 3 1.3 The development of CGCS2000 ................................................................................... 5 1.3.1 CGCS2000 putting into full application ................................................................... 5 1.3.2 Study on nonlinear movement of China Coordinate frame ...................................... 5 1.3.3 Study on epoch reference frame establishment ........................................................ 5 1.4 Construction and Service of National dynamic geocentric coordinate reference framework ................................................................................................................................. 6 1.5 BDS/GNSS data processing and analysis ..................................................................... 7 1.5.1 Introduction to BeiDou Navigation Satellite System (BDS)
    [Show full text]
  • China National Report on Geodesy
    2007-2010 China National Report on Geodesy For The XXV General Assembly of IUGG Melbourne, Australia, 27 June - 8 July 2011 By Chinese National Committee for The International Union of Geodesy and Geophysics Beijing, China June, 2011 2007-2010 China National Report on Geodesy by Chinese National Committee for IAG CONTENTS 1. Preface CHENG Pengfei and DANG Yamin 2. Modernization of China Geodetic Datum (2000-2010) CHEN Junyong, ZHANG Peng, ZHANG Yanping and DANG Yamin 3. The development of Compass/Beidou Satellite Navigation System TANG Jing, GE Xia, GAO Weiguang and YANG Yuanxi 4. Chinese Geodetic Coordinate System 2000 CHENG Pengfei, YANG Yuanxi, CHENG Yingyan, WEN Hanjiang, BEI Jinzhong and WANG Hua 5. The Data Processing and Analysis of National GNSS CORS Network in China DANG Yamin, ZHANG Peng, JIANG Zhihao and BEI Jinzhong 6. Progress in the Research on Earth Gravity Field of China NING Jinsheng, LI Jiancheng,CHAO Dingbo,JIN Taoyong and SHEN Wenbin 7. Progress in Geoid Determination Research Areas in China LI Jiancheng,CHAO Dingbo,SHEN Wenbin,ZHANG Shoujian,ZOU Xiancai,JIANG Weiping and YAO Yibin 8. National Report on Absolute and Superconducting Gravimetry SUN Heping, WANG Yong, XU Jianqiao, ZHANG Weimin and ZHOU Jiangcun 9. Progress of Underwater Gravity-aided Inertial Navigation WU Xiaoping and LI Shanshan 10. Crustal Deformation Monitoring and Geodynamic Mechanism Study in China XU Caijun and WEN Yangmao 11. Progress of Geodetic Data Processing Theory and Method in China ZHANG Liping and YANG Yuanxi 12. Some Activities of Astro-Geodynamics in China during 2007-2010 HUANG Chengli, WANG Guangli, WANG Xiaoya, WU Bin and ZHOU Yonghong 13.
    [Show full text]
  • China Geodetic Coordinate System 2000*
    UNITED NATIONS E/CONF.100/CRP.16 ECONOMIC AND SOCIAL COUNCIL Eighteenth United Nations Regional Cartographic Conference for Asia and the Pacific Bangkok, 26-29 October 2009 Item 7(a) of the provisional agenda Country Reports China Geodetic Coordinate System 2000* * Prepared by Pengfei Cheng, Hanjiang Wen, Yingyan Cheng, Hua Wang, Chinese Academy of Surveying and Mapping China Geodetic Coordinate System 2000 CHENG Pengfei，WEN Hanjiang，CHENG Yingyan， WANG Hua Chinese Academy of Surveying and Mapping, Beijing 100039, China Abstract Two national geodetic coordinate systems have been used in China since 1950’s, i.e.， the Beijing geodetic coordinate system 1954 and Xi’an geodetic coordinate system 1980. As non-geocentric and local systems, they were established based on national astro-geodetic network. Since 1990, several national GPS networks have been established for different applications in China, such as the GPS networks of order-A and order-B established by the State Bureau of Surveying and Mapping in 1997 were mainly used for the geodetic datum. A combined adjustment was carried out to unify the reference frame and the epoch of the control points of these GPS networks, and the national GPS control network 2000(GPS2000) was established afterwards. In order to establish the connection between CGCS2000 and the old coordinate systems and to get denser control points, so that the geo-information products can be transformed into the new system, the combined adjustment between the astro-geodetic network and GPS2000 network were also completed. China Geodetic Coordinate System 2000(CGCS2000) has been adopted as the new national geodetic reference system since July 2008，which will be used to replace the old systems.
    [Show full text]
  • Ground Control Survey Report
    GROUND CONTROL SURVEY REPORT Services provided by: 3001, INC. a Northrop Grumman company 10300 Eaton Place Suite 340 Fairfax, VA 22030 Ground Control Survey in Support of Topographic LIDAR, RGB Imagery and Hyperspectral Imagery of The Gulf Coast Region of Texas and Louisiana Contract # W91278-09-D-0010 Task Order 003 Services provided for: U. S. ARMY CORPS OF ENGINEERS MOBILE DISTRICT POST OFFICE BOX 2288 MOBILE, AL 36628-0001 1 CONTENTS 1. ABSTRACT ………..…………...………..………………………….3 2. SURVEY METHODOLOGY...……….....………………………….5 3. MAIN REPORT …………………………....………..……………...7 4. GPS NETWORK…….………..………………….………………..16 A. GPS Control Layout Map B. Fully Constrained C. Error Ellipses D. Histograms of Standardized Residuals 5. GROUND TRUTH SURVEY.…….…………….…….……..……28 A. Map of Ground Truth Locations B. Ground Truth Analysis of LIDAR Points 6. CONTROL MARK DATASHEETS………………..……………..50 7. GPS BASE LOGS…………………………………………………100 2 ABSTRACT 3 ABSTRACT This report documents the GPS ground surveys conducted in support of LIDAR, RGB Imagery and Hyperspectral Imagery data collection for the US Army Corps of Engineers, Mobile District. The data was collected between March 03, 2009 and March 11, 2009. The ground control stations were established utilizing two Trimble 5700 GPS receiver, three Trimble 4700 series GPS receivers and five Trimble 4000 series GPS receiver, three Trimble micro-centered L1/L2 antenna, two Trimble Zephyr Geodetic, and five Trimble Compact L1/L2 antennas with ground plane GPS antennas. There were no problems encountered during this survey. Following the control network surveys, surveys were conducted at 18 LIDAR Check sites and 43 Photo control points 13 were used as both utilizing the base stations established in the static network.
    [Show full text]
  • FDM 9-30 Real Time Kinematic (RTK) Surveys
    Facilities Development Manual Wisconsin Department of Transportation Chapter 9 Surveying and Mapping Section 30 Real Time Kinematic (RTK) Surveys FDM 9-30-1 Introduction March 31, 2017 1.1 Overview This section attempts to provide practical procedures and methods for using Real Time Kinematic (RTK) Global Navigation Satellite System (GNSS) to obtain consistent results for surveys performed by and for the Wisconsin Department of Transportation. The terms ‘GPS’ (Global Positioning System) and ‘GNSS’ (Global Navigation Satellite System) are often used interchangeably, but each of these terms has its own unique meaning. GNSS is an all-inclusive term used to describe a satellite navigation system from any country or region, while GPS refers specifically to the NAVSTAR satellite navigation system of the United States run by the Department of Defense. The most common GNSS systems are GPS (United States), GLONASS (Russia), Galileo (European Union), BeiDou (China) and QZSS (Japan). In the past, ‘GPS’ was synonymous with any form of satellite based positioning because, for a period of time, the United States GPS system was the only GNSS system available for civilian surveying applications. This section will use the term GNSS rather than GPS. RTK GNSS is a very good general observation tool for determining survey coordinates (horizontal and vertical) of a point. Some types of applications such as pavement matches and bridge decks require a more specific tool (e.g. total station) that RTK GNSS procedures should not be used for. Stated accuracies in this section are achievable by using proper survey techniques described in the following pages which are based on recommendations and information from the following publications: National Geodetic Survey (NGS) Manual “User Guidelines for Single Base Real Time GNSS Positioning” (W.
    [Show full text]
  • Geodetic Program Needs of Louisiana and Wisconsin
    GEODETIC PROGRAMS NEEDS OF LOUISIANA AND WISCONSIN Report to Congress U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service National Geodetic Survey August 2001 Donald L. Evans Secretary U.S. DEPARTMENT OF COMMERCE Scott B. Gudes Acting Under Secretary of Commerce for Oceans and Atmosphere and Administrator of National Oceanic and Atmospheric Administration Margaret A. Davidson Acting Assistant Administrator for Ocean Services and Coastal Zone Management National Ocean Service Charles W. Challstrom Director National Geodetic Survey August 2001 TABLE OF CONTENTS TABLE OF CONTENTS.................. i EXECUTIVE SUMMARY................. ii GEODETIC PROGRAM NEEDS OF LOUISIANA AND WISCONSIN . 1 REQUIREMENT FOR THE REPORT................1 INTRODUCTION.......................1 LOUISIANA ........................6 Background .....................6 Needs........................8 Potential Benefits ................ 11 Recommendations.................. 14 WISCONSIN ....................... 17 Background .................... 17 Needs....................... 19 Potential Benefits ................ 20 Recommendations.................. 24 GLOSSARY OF TERMS AND ACRONYMS .......... 25 i EXECUTIVE SUMMARY DIRECTION FROM CONGRESS This document was prepared in response to the direction contained in House Report 107-139 (to accompany H.R. 2500 - Departments of Commerce, Justice, and State, the Judiciary, and Related Agencies Appropriations Bill, Fiscal Year 2002) that the National Oceanic and Atmospheric Administration
    [Show full text]
  • Establishment of Geodetic Controls Network for Monitoring of Jimeta Bridge
    IMPACT: International Journal of Research in Engineering & Technology (IMPACT: IJRET) ISSN(P): 2347-4599; ISSN(E): 2321-8843 Vol. 5, Issue 8, Aug 2017, 41-50 © Impact Journals ESTABLISHMENT OF GEODETIC CONTROLS NETWORK FOR MONITORING OF JIMETA BRIDGE TAKANA ABUBAKAR & UMAR BUBA ALIYU Department of Surveying and Geoinformatics, Modibbo Adama University of Technology Yola, Nigeria ABSTRACT Bridges and flood control structures are subject to external forces that cause deformation of the structure itself, as well as its foundations. This is as a result of deflection in horizontal axis of the structure and/or settlement in vertical direction. Any indication of abnormal behavior, may threaten the safety of the structure. The need for establishing Geodetic Control Network for bridge deformation monitoring was addressed in this research. A Global Positioning System (GPS) receiver with the capabilities of accurate long-term monitoring was used. The designed scheme, therefore, involved the establishment of the geodetic control network within the study area and monuments on the bridge itself, as well as the sets of observations and adjustments using least squares as standard goal data for deformation monitoring. It also includes the observation procedure, analysis method, mathematical and statistical models for initial deformation monitoring on which subsequent deformation monitoring of the bridge will be based. The results of established monitoring network obtained determined the vector of structural deformation of Jimeta Bridge. KEYWORDS: Control Network, Deformation, Global Positioning System, INTRODUCTION In general, bridge and other flood control structures are subject to external forces that cause deformation and permeation of the structure itself as well as its foundations.
    [Show full text]
  • The Future of Vertical Geodetic Control
    1 The Future of Vertical Geodetic Control G. Steinberg H. Papo Survey of Israel Technion, Israel Institute of Technology Abstract The phenomenal progress made by motorized leveling in the past two decades has not changed the status of vertical geodetic control (VGC) worldwide. Only a few countries have been able to establish and to maintain (re-observe at reasonably short time intervals) their national VGC networks at first order accuracies. The establishment of a national VGC network by precise leveling has been indeed a technical possibility for many years and for some countries it has been even economically affordable. We claim that today those national VGC networks are not indispensable. Due to their many drawbacks such as high cost, slow pace, obstacle-crossing impotence and monumentation problems, we believe that they are going to be replaced in the near future by a more attractive alternative. The alternative we envision is a national VGC network based on GPS measurements which forms an integral part of a 3-D spatial network. The reference surface is the WGS84 (or any future equivalent) ellipsoid and thus the system of heights is ellipsoidal and not orthometric. We believe that the switch from orthometric (OVGC) to ellipsoidal (EVGC) height systems at the national (or at the continental or even at the worldwide) level is imminent and inevitable. OVGC networks may continue to be used in the future but that only in the form of floating islands with a limited geographical extent. Viable candidates for such orthometric islands are regions and projects where the use of orthometric heights remains mandatory.
    [Show full text]
  • Geodetic Network Design and Strategies Followed for Drilling a 25 Km Tunnel for High Speed Railway in Spain
    Geodetic network design and strategies followed for drilling a 25 km tunnel for high speed railway in Spain Jesus VELASCO, Juan PRIETO, Tomas HERRERO and Jose FABREGA, Spain Key words: TBM, tunnel breakthrough, underground network, surface network, accuracy, gyrotheodolite azimuth SUMMARY During the last years several large high-speed railway tunnels have been built in Spain. To solve these projects, technical and scientific problems have been solved from the geodetic and surveying point of view. These studies have allowed us to set a methodology that optimizes the performance of this kind of works in the world of Civil Engineering. We have applied our studies to the Tunnels of Pajares that are the second longest ones in Spain with a total longitude of about 25 km. The studies summarize the design of the geodetic networks to support the guidance of the TBMs used as well as the election of the observations to be done, the instrumental to be used and the observation and computation procedures to be followed. A special emphasis has been taken into account for the treatment of the uncertainty of the coordinates, displacements and breakthrough obtained during the drilling tasks. The article shows the results obtained and the conclusions that can be followed in order to successfully complete a similar project. TS 6H - Engineering Surveys I 1/18 Jesus Velasco, Juan Prieto, Tomas Herrero and Jose Fabrega Geodetic network design and strategies followed for drilling a 25 km tunnel for high speed railway in Spain FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11-16 April 2010 Geodetic network design and strategies followed for drilling a 25 km tunnel for high speed railway in Spain Jesus VELASCO, Juan PRIETO, Tomas HERRERO and Jose FABREGA, Spain 1.
    [Show full text]