• Define Projection vs Project... a visual guide

    There is ... still ... confusion regarding the proper use of the  Define Projection Tool versus the Project Tool.    "my data don't line up..." "I am sure about the coordinate system..." "eve...
    spk578
    created by spk578
  • Moving from Static Spatial Reference Systems in 2022

    This is a publication by @JimBaumann in ARCUSER.   In 2008, the National Geodetic Survey (NGS) announced in its 10-year plan the replacement of the country’s two national datums: North American Datum ...
    spk578
    last modified by spk578
  • US datum modernization coming in 2022

    The US National Geodetic Survey (NGS) is implimenting a plan to replace NAD 83 and NAVD 88 through a modernization effort.   NGS’s main page on the subject: https://www.ngs.noaa.gov/datums/newdatums...
    MKennedy-esristaff
    last modified by MKennedy-esristaff
  • Checklist: Adding coordinate values from a spreadsheet

    Importing data from a spreadsheet   There has been an increase in queries regarding the import of coordinate values from spreadsheets into ArcGIS Desktop and ArcGIS Pro. With that in mind, find a check...
    spk578
    last modified by spk578
  • Adding a Newer Coordinate System Definition to an Older Version of ArcMap

    Let’s say the latest version of ArcMap includes the definition of your country’s latest coordinate system and you would like to use it in your version of ArcMap. For that you need to export the new definit...
  • The Night Sky: Making a Star Chart with ArcGIS Pro

    I discovered this amazing, well I think it is amazing, find recently and though to share how you can create a beautiful star chat using ArcGIS Pro. This StoryMap is made by Heather Smith you can find more information ...
    spk578
    last modified by spk578
  • Devices using Europe’s GNSS Galileo

    Galileo is Europe’s Global Satellite Navigation System (GNSS), providing users with improved positioning and timing information.   The project has been running since the launch of the first ...
    spk578
    last modified by spk578
  • The Vertical Datum: Or is that Mean Sea level?

    What is a Vertical Datum? The Geodetic Glossary (2009) defines height as ‘distance, measured along a perpendicular, between a point and a reference surface’. This definition is concise and direct but leav...
    spk578
    last modified by spk578
  • Geodesic distances: How long is that line again?

    What are Geodesic distances?   A geodesic line is the shortest path between two points on a curved surface, like the Earth. They are the analogue of a straight line on a plane surface or whose sectioning plane a...
    spk578
    last modified by spk578
  • Drifting of the celestial sphere: What is J2000?

    What does the "2000" mean at the end of the coordinate system names in the Solar System folder?   You can also find reference to the number in the details of the *.prj file itself.   GEOGCS["GCS...
    spk578
    last modified by spk578
  • Planetary Coordinate Systems: The Moon

    Planetary Coordinate Reference Systems There is an interesting but perhaps little-used folder of *.prj files called “Solar System”. As someone interested in geodesy and its application it is particula...
    spk578
    last modified by spk578
  • Distance on an ellipsoid: Vincenty's Formulae

    Vincenty's Formulae are two methods named after Thaddeus Vincenty a Polish-American geodesist who lived during the 20th Century. During his career, he devised his formulae as well as contributing to major project...
    spk578
    last modified by spk578
  • Distance on a sphere: The Haversine Formula

    I decided to look into some of the mathematics that makes it possible to calculate distances considering 3D space, for example, calculating distance on a sphere. You can find our more on geodesic distances from the pr...
    spk578
    last modified by spk578
  • Finding Knowledge Base or Technical Articles

    While fine-tuning a technical workshop for next week, my co-presenter and I realized that our comment of "don't forget these knowledge base articles!" (see terminology note below) wasn't very helpful. You used to be a...
    MKennedy-esristaff
    last modified by MKennedy-esristaff
  • Global Geodetic Reference Frame (GGRF)

    Introduction The Global Geodetic Reference Frame (GGRF) is the realisation of the Global Geodetic Reference System (GGRS). The GGRS comprises terrestrial and celestial components allowing users to precisely...
    spk578
    created by spk578
  • Some thoughts on datum realizations and transformations

    A customer had some questions on why Esri has "null" or "bookkeeping" transformations as well as why there are transformations which have the same parameter values, but convert between multiple geographic coordinate s...
    MKennedy-esristaff
    last modified by MKennedy-esristaff
  • The European Datum: A History (Part 3)

    The Central European Net (CEN ) The European datum began its life as the Central European First-Order Triangulation Adjustment (Hough, 1947) this project began in April 1945 after the U.S Third Army with the HOUGHTEAM...
    spk578
    created by spk578
  • The European Datum: A History (Part 2)

    Introduction In Part 1 of this series we saw the setting for the development of a proto European-wide datum by the Germans. This super-National Datum was originally driven from the need of political and military power...
    spk578
    last modified by spk578
  • Listing Transformations for an Area with ArcMap and ArcPy

    A common question asked when working with Coordinate Reference Systems (CRS) in ArcMap is not only how to transform between different CRS but simply what transformations are available between two CRS in a given area? ...
    spk578
    last modified by spk578
  • The Antipodes...finding summer all year long!

    What is an antipode? Any point on the surface of a sphere, in this case the Earth, that lies diametrically opposite from a given point on the same surface, so that a line drawn between the two points through the cente...
    spk578
    last modified by spk578