Datums in Texas NGS: Welcome to Geodesy
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Shaded Elevation Map of Ohio
STATE OF OHIO DEPARTMENT OF NATURAL RESOURCES DIVISION OF GEOLOGICAL SURVEY Ted Strickland, Governor Sean D. Logan, Director Lawrence H. Wickstrom, Chief SHADED ELEVATION MAP OF OHIO 0 10 20 30 40 miles 0 10 20 30 40 kilometers SCALE 1:2,000,000 427-500500-600600-700700-800800-900900-10001000-11001100-12001200-13001300-14001400-1500>1500 Land elevation in feet Lake Erie water depth in feet 0-6 7-12 13-18 19-24 25-30 31-36 37-42 43-48 49-54 55-60 61-66 67-84 SHADED ELEVATION MAP This map depicts the topographic relief of Ohio’s landscape using color lier impeded the southward-advancing glaciers, causing them to split into to represent elevation intervals. The colorized topography has been digi- two lobes, the Miami Lobe on the west and the Scioto Lobe on the east. tally shaded from the northwest slightly above the horizon to give the ap- Ridges of thick accumulations of glacial material, called moraines, drape pearance of a three-dimensional surface. The map is based on elevation around the outlier and are distinct features on the map. Some moraines in data from the U.S. Geological Survey’s National Elevation Dataset; the Ohio are more than 200 miles long. Two other glacial lobes, the Killbuck grid spacing for the data is 30 meters. Lake Erie water depths are derived and the Grand River Lobes, are present in the northern and northeastern from National Oceanic and Atmospheric Administration data. This digi- portions of the state. tally derived map shows details of Ohio’s topography unlike any map of 4 Eastern Continental Divide—A continental drainage divide extends the past. -
Meyers Height 1
University of Connecticut DigitalCommons@UConn Peer-reviewed Articles 12-1-2004 What Does Height Really Mean? Part I: Introduction Thomas H. Meyer University of Connecticut, [email protected] Daniel R. Roman National Geodetic Survey David B. Zilkoski National Geodetic Survey Follow this and additional works at: http://digitalcommons.uconn.edu/thmeyer_articles Recommended Citation Meyer, Thomas H.; Roman, Daniel R.; and Zilkoski, David B., "What Does Height Really Mean? Part I: Introduction" (2004). Peer- reviewed Articles. Paper 2. http://digitalcommons.uconn.edu/thmeyer_articles/2 This Article is brought to you for free and open access by DigitalCommons@UConn. It has been accepted for inclusion in Peer-reviewed Articles by an authorized administrator of DigitalCommons@UConn. For more information, please contact [email protected]. Land Information Science What does height really mean? Part I: Introduction Thomas H. Meyer, Daniel R. Roman, David B. Zilkoski ABSTRACT: This is the first paper in a four-part series considering the fundamental question, “what does the word height really mean?” National Geodetic Survey (NGS) is embarking on a height mod- ernization program in which, in the future, it will not be necessary for NGS to create new or maintain old orthometric height benchmarks. In their stead, NGS will publish measured ellipsoid heights and computed Helmert orthometric heights for survey markers. Consequently, practicing surveyors will soon be confronted with coping with these changes and the differences between these types of height. Indeed, although “height’” is a commonly used word, an exact definition of it can be difficult to find. These articles will explore the various meanings of height as used in surveying and geodesy and pres- ent a precise definition that is based on the physics of gravitational potential, along with current best practices for using survey-grade GPS equipment for height measurement. -
State Plane Coordinate System
Wisconsin Coordinate Reference Systems Second Edition Published 2009 by the State Cartographer’s Office Wisconsin Coordinate Reference Systems Second Edition Wisconsin State Cartographer’s Offi ce — Madison, WI Copyright © 2015 Board of Regents of the University of Wisconsin System About the State Cartographer’s Offi ce Operating from the University of Wisconsin-Madison campus since 1974, the State Cartographer’s Offi ce (SCO) provides direct assistance to the state’s professional mapping, surveying, and GIS/ LIS communities through print and Web publications, presentations, and educational workshops. Our staff work closely with regional and national professional organizations on a wide range of initia- tives that promote and support geospatial information technologies and standards. Additionally, we serve as liaisons between the many private and public organizations that produce geospatial data in Wisconsin. State Cartographer’s Offi ce 384 Science Hall 550 North Park St. Madison, WI 53706 E-mail: [email protected] Phone: (608) 262-3065 Web: www.sco.wisc.edu Disclaimer The contents of the Wisconsin Coordinate Reference Systems (2nd edition) handbook are made available by the Wisconsin State Cartographer’s offi ce at the University of Wisconsin-Madison (Uni- versity) for the convenience of the reader. This handbook is provided on an “as is” basis without any warranties of any kind. While every possible effort has been made to ensure the accuracy of information contained in this handbook, the University assumes no responsibilities for any damages or other liability whatsoever (including any consequential damages) resulting from your selection or use of the contents provided in this handbook. Revisions Wisconsin Coordinate Reference Systems (2nd edition) is a digital publication, and as such, we occasionally make minor revisions to this document. -
Geographical Influences on Climate Teacher Guide
Geographical Influences on Climate Teacher Guide Lesson Overview: Students will compare the climatograms for different locations around the United States to observe patterns in temperature and precipitation. They will describe geographical features near those locations, and compare graphs to find patterns in the effect of mountains, oceans, elevation, latitude, etc. on temperature and precipitation. Then, students will research temperature and precipitation patterns at various locations around the world using the MY NASA DATA Live Access Server and other sources, and use the information to create their own climatogram. Expected time to complete lesson: One 45 minute period to compare given climatograms, one to two 45 minute periods to research another location and create their own climatogram. To lessen the time needed, you can provide students data rather than having them find it themselves (to focus on graphing and analysis), or give them the template to create a climatogram (to focus on the analysis and description), or give them the assignment for homework. See GPM Geographical Influences on Climate – Climatogram Template and Data for these options. Learning Objectives: - Students will brainstorm geographic features, consider how they might affect temperature and precipitation, and discuss the difference between weather and climate. - Students will examine data about a location and calculate averages to compare with other locations to determine the effect of geographic features on temperature and precipitation. - Students will research the climate patterns of a location and create a climatogram and description of what factors affect the climate at that location. National Standards: ESS2.D: Weather and climate are influenced by interactions involving sunlight, the ocean, the atmosphere, ice, landforms, and living things. -
Part V: the Global Positioning System ______
PART V: THE GLOBAL POSITIONING SYSTEM ______________________________________________________________________________ 5.1 Background The Global Positioning System (GPS) is a satellite based, passive, three dimensional navigational system operated and maintained by the Department of Defense (DOD) having the primary purpose of supporting tactical and strategic military operations. Like many systems initially designed for military purposes, GPS has been found to be an indispensable tool for many civilian applications, not the least of which are surveying and mapping uses. There are currently three general modes that GPS users have adopted: absolute, differential and relative. Absolute GPS can best be described by a single user occupying a single point with a single receiver. Typically a lower grade receiver using only the coarse acquisition code generated by the satellites is used and errors can approach the 100m range. While absolute GPS will not support typical MDOT survey requirements it may be very useful in reconnaissance work. Differential GPS or DGPS employs a base receiver transmitting differential corrections to a roving receiver. It, too, only makes use of the coarse acquisition code. Accuracies are typically in the sub- meter range. DGPS may be of use in certain mapping applications such as topographic or hydrographic surveys. DGPS should not be confused with Real Time Kinematic or RTK GPS surveying. Relative GPS surveying employs multiple receivers simultaneously observing multiple points and makes use of carrier phase measurements. Relative positioning is less concerned with the absolute positions of the occupied points than with the relative vector (dX, dY, dZ) between them. 5.2 GPS Segments The Global Positioning System is made of three segments: the Space Segment, the Control Segment and the User Segment. -
TOPOGRAPHIC MAP of OKLAHOMA Kenneth S
Page 2, Topographic EDUCATIONAL PUBLICATION 9: 2008 Contour lines (in feet) are generalized from U.S. Geological Survey topographic maps (scale, 1:250,000). Principal meridians and base lines (dotted black lines) are references for subdividing land into sections, townships, and ranges. Spot elevations ( feet) are given for select geographic features from detailed topographic maps (scale, 1:24,000). The geographic center of Oklahoma is just north of Oklahoma City. Dimensions of Oklahoma Distances: shown in miles (and kilometers), calculated by Myers and Vosburg (1964). Area: 69,919 square miles (181,090 square kilometers), or 44,748,000 acres (18,109,000 hectares). Geographic Center of Okla- homa: the point, just north of Oklahoma City, where you could “balance” the State, if it were completely flat (see topographic map). TOPOGRAPHIC MAP OF OKLAHOMA Kenneth S. Johnson, Oklahoma Geological Survey This map shows the topographic features of Oklahoma using tain ranges (Wichita, Arbuckle, and Ouachita) occur in southern contour lines, or lines of equal elevation above sea level. The high- Oklahoma, although mountainous and hilly areas exist in other parts est elevation (4,973 ft) in Oklahoma is on Black Mesa, in the north- of the State. The map on page 8 shows the geomorphic provinces The Ouachita (pronounced “Wa-she-tah”) Mountains in south- 2,568 ft, rising about 2,000 ft above the surrounding plains. The west corner of the Panhandle; the lowest elevation (287 ft) is where of Oklahoma and describes many of the geographic features men- eastern Oklahoma and western Arkansas is a curved belt of forested largest mountainous area in the region is the Sans Bois Mountains, Little River flows into Arkansas, near the southeast corner of the tioned below. -
HORIZONTAL DATUM CONVERSIONS Helping Vermonters Visualize Choice
PART 3: SECTION K HORIZONTAL DATUM CONVERSIONS Helping Vermonters Visualize Choice A Discussion, Examples, and Recommended Conversion Methodology for the Transformation of ARC/INFO Coverages from the North American Datum of 1927 to the North American Datum of 1983 in Vermont. This paper would not have been made available without the thoughtful writing of Milo Robinson, NGS Geodetic Advisor to the State of Vermont, and Gary Smith of Green Mountain Geographics. These recognized leaders in the VGIS community have all of our thanks. EXECUTIVE SUMMARY This paper outlines the steps required to convert ARC/INFO coverages from the North American Datum of 1927 (NAD27) to the more accurate North American Datum of 1983 (NAD83). Until recently, most contemporary maps of Vermont used the NAD27 as the reference datum. This made it the logical option for direct digital conversion and subsequent inclusion in the Vermont GIS database. With the arrival of the new Vermont Digital Orthophotography, expanded GPS activity and new maps from the U.S. Geological Survey being prepared using NAD83, it is increasingly necessary to convert existing NAD27 data to NAD83 to properly incorporate new information. The need of particular data developers or users to convert data depends on the location in the State, and particular mapping requirements. As this paper is released the Vermont counties for which NAD83 digital orthophotos are available are Rutland, Windsor, Franklin, Grand Isle and Addison, plus portions of Washington County. The remainder of Washington and Orange Counties will be available soon, with the remainder of Vermont to be processed in coming years. The remainder of this paper provides more detail on the datum change, suggests new data entry guidelines, details the coordinate and naming convention for Vermont's orthophotos, and provides the procedures for converting Vermont's NAD27 data to NAD83 using software by ESRI (Environmental Systems Research Institute, Redlands, CA). -
Vertical Datum Conversion Guidance
Guidance for Flood Risk Analysis and Mapping Vertical Datum Conversion May 2014 This guidance document supports effective and efficient implementation of flood risk analysis and mapping standards codified in the Federal Insurance and Mitigation Administration Policy FP 204- 07801. For more information, please visit the Federal Emergency Management Agency (FEMA) Guidelines and Standards for Flood Risk Analysis and Mapping webpage (http://www.fema.gov/guidelines-and- standards-flood-risk-analysis-and-mapping), which explains the policy, related guidance, technical references, and other information about the guidelines and standards process. Nothing in this guidance document is mandatory other than standards codified separately in the aforementioned Policy. Alternate approaches that comply with FEMA standards that effectively and efficiently support program objectives are also acceptable. Vertical Datum Conversion May 2014 Guidance Document 24 Page i Document History Affected Section or Date Description Subsection Initial version of new transformed guidance. The content was derived from the Guidelines and Specifications for Flood First Publication May 2014 Hazard Mapping Partners, Procedure Memoranda, and/or Operating Guidance documents. It has been reorganized and is being published separately from the standards. Vertical Datum Conversion May 2014 Guidance Document 24 Page ii Table of Contents 1.0 Overview .................................................................................................................................. -
Mind the Gap! a New Positioning Reference
A new positioning reference Why is the United States adopting NATRF2022? What are we doing about this in Canada? We want to hear from you! • The Canadian Geodetic Survey and the United States • Improved compatibility with Global Navigation • The Canadian Geodetic Survey is working closely National Geodetic Survey have collaborated for Satellite Systems (GNSS), such as GPS, is driving this with the United States National Geodetic Survey in • Send us your comments, the challenges you over a century to provide the fundamental reference change. The geometric reference frames currently defining reference frames to ensure they will also foresee, and any concerns to help inform our path Mind the gap! systems for latitude, longitude and height for their used in Canada and the United States, although be suitable for Canada. forward to either of these organizations: respective countries. compatible with each other, are offset by 2.2 m from • Geodetic agencies from across Canada are A new positioning reference the Earth’s geocentre, whereas GNSS are geocentric. - Canadian Geodetic Survey: nrcan. • Together our reference systems have evolved collaborating on reference system improvements geodeticinformation-informationgeodesique. to meet today’s world of GPS and geographical • Real-time decimetre-level accuracies directly from through the Canadian Geodetic Reference System [email protected] NATRF2022 information systems, while supporting legacy datums GNSS satellites are expected to be available soon. Committee, a working committee of the Canadian -
JHR Final Report Template
TRANSFORMING NAD 27 AND NAD 83 POSITIONS: MAKING LEGACY MAPPING AND SURVEYS GPS COMPATIBLE June 2015 Thomas H. Meyer Robert Baron JHR 15-327 Project 12-01 This research was sponsored by the Joint Highway Research Advisory Council (JHRAC) of the University of Connecticut and the Connecticut Department of Transportation and was performed through the Connecticut Transportation Institute of the University of Connecticut. The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Connecticut or the Connecticut Department of Transportation. This report does not constitute a standard, specification, or regulation. i Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. JHR 15-327 N/A 4. Title and Subtitle 5. Report Date Transforming NAD 27 And NAD 83 Positions: Making June 2015 Legacy Mapping And Surveys GPS Compatible 6. Performing Organization Code CCTRP 12-01 7. Author(s) 8. Performing Organization Report No. Thomas H. Meyer, Robert Baron JHR 15-327 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) University of Connecticut N/A Connecticut Transportation Institute 11. Contract or Grant No. Storrs, CT 06269-5202 N/A 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Connecticut Department of Transportation Final 2800 Berlin Turnpike 14. Sponsoring Agency Code Newington, CT 06131-7546 CCTRP 12-01 15. Supplementary Notes This study was conducted under the Connecticut Cooperative Transportation Research Program (CCTRP, http://www.cti.uconn.edu/cctrp/). -
Evolution of NAD 83 in the United States: Journey from 2D Toward 4D
Evolution of NAD 83 in the United States: Journey from 2D toward 4D Richard A. Snay1 Abstract: In 1986, Canada, Greenland, and the United States adopted the North American Datum of 1983 (NAD 83) to replace the North American Datum of 1927 as their official spatial reference system for geometric positioning. The rigor of the original NAD 83 realization benefited from the extensive use of electronic distance measuring instrumentation and from the use of both TRANSIT Doppler observations and very long baseline interferometry observations. However, the original NAD 83 realization predated the widespread use of the global po- sitioning system and the use of continuously operating reference stations. Consequently, NAD 83 has evolved significantly in the United States since 1986 to embrace these technological advances, as well as to accommodate improvements in the understanding of crustal motion. This paper traces this evolution from what started as essentially a two-dimensional (2D) reference frame and has been progressing toward a four-dimensional (4D) frame. In anticipation of future geodetic advances, the U.S. National Geodetic Survey is planning to replace NAD 83 about a decade from now with a newer, more geocentric spatial reference system for geometric positioning. DOI: 10.1061/(ASCE)SU.1943- 5428.0000083. © 2012 American Society of Civil Engineers. CE Database subject headings: History; Datum; Transformations; Geodetic surveys; North America. Author keywords: History; Datum transformations; Dynamic datums; Crustal deformation; NAD 83. Introduction height, and how these three coordinates vary over time. NAD 27 provided a foundation for measuring only geodetic latitude and lon- In 1986 a group of institutions representing Canada, Greenland, and gitude; therefore, it is considered a horizontal datum. -
Using a Surveyor's Level to Generate a Topographical
Using a Surveyor’s Level to Generate a Topographical Map This application note describes the process of using a surveyor's level for generating a topography (topo) map. The site survey described below uses San Francisco's Yerba Buena Gardens as a site for recording relative elevations over a specific area. With these relative elevations organized into a grid, a topographical map can be created. Equipment: (most available from Tool Lending Library): Surveyor's Level Level Tripod Leveling Rod Compass 100' Tape Measure Notebook and Pencil Procedure: Step 1: Find a Reference Point (Benchmark Elevation) Step 2: Set up the Surveyor's Level Step 3: Reading the Leveling Rod Step 4: Taking Readings Step 5: Make a Grid Over the Chosen Plot Step 6: Making Sense of the Collected Data Step 7: Drawing Topography Lines Figure 1: Surveyor’s level Step 1: Find a Reference Point (Benchmark Elevation) 1. Establish a reference point, also known as the benchmark elevation. A list of official benchmark elevations in San Francisco is available from the Bureau of Street Use and Mapping. (located at 875 Stevenson Street, Room 460 /// San Francisco, CA. 94103 /// 415.554.5810). The nearest benchmark to the plot is the intersection of 4th and Mission Street. (Figure 2). Using a Surveyor’s Level to Generate a Topography Map Page 1 of 8 Copyright© Pacific Gas and Electric Company, all rights reserved www.pge.com/pec Figure 2: Benchmark descriptions as printed by the SF Bureau of Street Use and Mapping. The benchmark on the list in Figure 2 is a fire hydrant with the word "OPEN" on top.