TRIANGULATION ON THE OBLATE SPHEROID EARTH
Lake Pontchartrain – Maps and Charts
Triangulation Diagrams –
Geodetic Control Diagrams –
Nautical Charts –
Topographic Maps –
NGS Geodetic Control Data Sheets –
Geodesy And Construction
An Example of Horizontal Geodetic Control for Bridge Engineering and Planning – Lake Pontchartrain Causeway Bridge Triangulation Network
An Example of Geodetic Control for Highway Location and Engineering
Example of State Boundary Control
Basic Surveying For Brian
Brian Leake claims to have 30 years of surveying experience. When I attempted to have a conversation with him about his surveying experience, I learned that he has none. None at all. He has never made any surveying measurements, ever. At most, Brian has checked some grades using an auto level in his job as a construction worker. It’s no wonder Brian believes the earth is flat when he also believes that his work on construction sites counts as 30 years of surveying experience. But, it’s never too late to learn, so I put together some references below that can be helpful to Brian if he chooses to look at them. He lives in Florida, so I made sure to include materials specific to his home state.
BASIC SURVEYING – THEORY AND PRACTICE
FUNDAMENTAL SURVEYING – THEORY AND PRACTICE
Florida State Plane Coordinates
FLORIDA DEPARTMENT OF TRANSPORTATION SURVEYING AND MAPPING HANDBOOK MARCH 29, 2019
FDOT Districts State Plane & UTM Zones
FDOT Surveying & Mapping – Documents & Publications
Florida Surveying & Mapping Society
Chesapeake Bay
For those interested to see where Travis aka The Plane Truth records his videos through the highly refracted atmosphere near to the water surface of The Chesapeake Bay, I am posting the links you can click on to download PDF files of the Nautical Charts and Surveying Triangulation Diagrams showing the locations of the land features, infrastructure, buoys, and lighthouses visible in his videos.
The murky “eatherband” that Travis talks about does not prevent us from performing accurate surveys to locate all the features plotted on these maps and charts. That is because surveyors know better than to attempt making measurements down low near the water surface where Travis records his blurry videos.
Potomac River, Chesapeake Bay to Piney Point, Maryland-Virginia (557) May 1979
Chesapeake Bay, Cove Point to Sandy Point (1225) MD, Feb. 1979
Chesapeake Bay, Smith Point to Cove Point, MD – VA (1224) April 1979
Chesapeake Bay, Wolf Trap to Smith Point (1223) MD – VA, Jan. 1972
Maryland & Delaware (Northeast Section)
Maryland & Delaware (Southeast Section)
Baltimore_Maryland_VA_WV_PA_NJ_18_1
NOAA Chart – 12280 – CHEAPEAKE BAY
NOAA Chart – 12273 – CHESAPEAKE BAY SANDY POINT TO SUSQUEHANNA RIVER
Surveying Instruments – Curvature & Refraction Corrections
SOKKIA iX-1000 seriesiX-500 series intelligence X-ellence Station OPERATOR’S MANUAL
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TOPCON GTS-220 SERIES ELECTRONIC TOTAL STATION INSTRUCTION MANUAL
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LEICA TPS1100 Professional Series User Manual
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NIKON Total Station NPL-322 Instruction Manual
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TRIMBLE S SERIES TOTAL STATIONS
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Reciprocal Zenith Angle Projects
In this blog post, I am sharing the projects I conducted to record reciprocal zenith angles measured with very high precision theodolites and total station instruments.
Walter Bislin evaluated some of these projects and included the observation data on his blog post – Determining the Shape of the Earth with Zenith Angle Measurements
This first project that I am including here in this blog post is not one that I performed, but was observed by Charlie Glover, who shared it with me by email. Here is the blog entry I made to share the information that he sent to me – Long Line EDM & Reciprocal Zenith Angles – A Measure Of The Plumbline Tilt.
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Refer to YouTube Video “Flat Level Lake Measurements – Flat Earth Proof? Oct 27, 2016
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Blog Post – “Flat Earth Proof? – Perfectly Flat Level Lake”
Refer to YouTube video “Perfectly Flat Level Lake” Nov 18, 2016
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Blog Post – “One Mile Level Line”
Refer to YouTube video “One Mile Level Line” Nov 25, 2016
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Google Earth Street View Picked Up My Survey Points From 2018 – Cool ! Oct 21, 2020
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11 Miles Signal Mirror – “I can see it!” 😉 6 of 6 Streamed live on Dec 12, 2018
Reciprocal Zenith Angles 12/11/18, 5 of 6 Streamed live on Dec 11, 2018
Reciprocal Zenith Angles 12/10/18, 3 of 6 Streamed live on Dec 10, 2018
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Your GNSS Vectors Match Your EDM Slope Measurements
Your GNSS Vectors Match Your EDM Slope Measurements – In Case You Didn’t Know 😉
Feb 24, 2020 (PDF download)
If you wonder about things like grid-ground and you aren’t sure why you might be seeing differences between your GPS measurements and your total station measurements, here is a little exercise you can run through to firm up your understanding and increase your confidence in your approach to combining these 2 measurement technologies in your daily surveying practice.
Try going to your local EDM CBL nearest to your town to measure it with your GPS. Note that the published lengths are NOT projected to the state plane grid or computed as ellipsoid distances. They are actual slope distances measured by NGS using high precision EDM instruments. They reduced their slope measurements to the published mark-to-mark lengths and the horizontal lengths. Note the accuracy is published at tenths of millimeters.
See here for an example –
Texas EDM CBLs
https://www.ngs.noaa.gov/CBLINES/BASELINES/tx
You can compare your EDM slope measurements with the published mark-to-mark lengths to make sure your instrument is working properly. In some states, in order to qualify to perform work for the DOT or other agencies, you are required to measure an NGS EDM CBL using your GPS to verify your equipment, methods and procedures are all working properly.
Using 2, 3, or 4 GNSS receivers, log data occupying all the marks to obtain simultaneous data sets between each pair of marks. Then post-process all the baselines between all the marks. Note, you do NOT have to select a grid coordinate system to process that raw GNSS data. That is because the raw GNSS data is NOT referenced to the state plane coordinate system OR the ellipsoid as some may assume. Rather, the positions resulting from GNSS measurements are referenced to the WGS84 ECEF 3D Cartesian Coordinate System which is basically a box centered at the Earth’s mass center as the origin being 0,0,0 meters.
ECEF coordinates in relation to latitude and longitude
https://en.wikipedia.org/wiki/ECEF#/media/File:Ecef.png
The ECEF coordinates are then converted to Latitude, Longitude, and Ellipsoid Heights and these geographic coordinates are then projected to mapping surfaces such as UTM, SPCS and other national grid systems. But, that is beyond the focus of this drill comparing your GNSS vectors with your EDM slope distances using the native ECEF vector components.
So, continuing to the next step of making the comparison, all you need to do is open a new project to start a post processing session and select US Survey Feet as the units. Then, process the raw data to solve all the baselines which will be displayed as delta X, Y, and Z between all the points and the vector lengths will match the published EDM CBL mark-to-mark lengths AND your EDM slope measurements. EDM slope length = GNSS vector length. [ SQRT(dX^2 + dY^2 + dZ^2)= straight vector between the 2 points) ]
And by the way, you can do this same test using RTK instead of post-processing. Just place your Base receiver on a mark and observe all the other marks with your Rover. For a full data set on that EDM CBL, move your Base to each mark and repeat the whole process. RTN and VRS are not well suited to make this direct comparison between GNSS vectors and EDM slope distances.
One more thing. There are some EDM CBLs that have some of their marks included in the NGS database, meaning those marks have PIDs and their positions are available on a published datasheet. If your EDM CBL has published positions, you are fortunate because there is more fun to be had using those datasheets after you complete this little drill of comparing your GNSS vectors with your EDM slope distances described herein. And stay tuned for the next step, combining GNSS vectors and total station measurements in a least squares adjustment.
In this old article linked below, originally printed as a series of 3 installments for Professional Surveyor magazine, I purposely chose to use an example located near sea level in order to make an important point about scale factors. The EDM CBL comparison with GNSS vectors example is in this paper too. Go out and try it for yourself. Any uncertainty you had about grid-ground will disappear after you enjoy a day at your local EDM CBL performing this exercise.
GPS & EDM Measurements – Why Don’t They Match?
http://www.sawj.org/files/drupal4/GPS_Vs_EDM.pdf
EDMI Calibration Base Line Program
https://www.ngs.noaa.gov/CBLINES/calibration.shtml
NOAA Technical Memorandum NOS NGS-10: Use of Calibration Base Lines, by Fronczek, December 1977, reprinted 1980, 38 pp.
Jesse Kozlowski, Surveyor 
