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All People > MidnightYell2003 > Adrian Welsh's Blog > 2016 > November

I really liked how Denzel Washington used the phrase “explain this to me as if I were a xxx-year-old” in the movie Philadelphia (1993).

Reference: Philadelphia. Philadelphia, PA: Jonathan Demme, 1993. film.


So, I will take it one step further and attempt to explain the concept of georeferencing to an actual five-year-old.




Five-year-old engineer says, “I have this PDF of a site plan. I want to put this on a map and have it line up properly.”



Here is my map.



We need to zoom in a little bit closer.


Open Street Map 1:100,000<-- click to make larger


A little bit more.


Open Street Map 1:5,000<-- click to make larger


Almost there. Zoom in some more so that our site plan will fit better.


Open Street Map 1:1,050<-- click to make larger


Much better. Now, we need to shrink the site plan to a more usable size. Currently, it’s larger than our map.



Let’s make it a little bit smaller.



Perfect. Now we need to place the site plan on our zoomed in map and adjust it to fit by rotating it and resizing it.



Great! Now, after some quality control of adjustments and transformations, we can rectify this image and call it georeferenced!


OSM 1:1,050 with Image<-- click to make larger


We can make the georeferenced image transparent to where we can see the basemap behind it.


OSM 1:1,050 with Image, Transparency 50%<-- click to make larger


Finally, we can add existing linework and other GIS files to give the image a more solid reference.


OSM 1:1,050 with Image, Transparency 50% and Linework<-- click to make larger





Please leave comments and let me know if this is helpful and/or what I should change with this blog post. Thanks for reading!

Happy Thanksgiving, everyone! (at least, it is Thanksgiving time in the US). I thought this would give me a fun chance to write a blog post on “GIS for Dummies”, but with a cooking/recipe twist, Thanksgiving style. Some folks at my office and I came up with this idea and this would be a good place to share it.


For starters, this is GIS:


GIS: A Map, But More Than a Map

  • A way to capture, store, manipulate, analyze, and present data
  • A series of layered geospatial data organized in one space
  • A way to solve problems and answer complex questions


However, let’s make it fun so that anyone can understand.


GIS for Dummies Recipe




  • 4 parts Database
  • 1 1/2 parts Geographic Data
    • Points, Lines, Polygons, Rasters, DEM, and 3D Data
  • 1 part Data from Forms / Spreadsheets (Tabular Data)
    • Address Lists, GPS Coordinates, and Files
  • 1/2 part Basemap
    • Satellite Imagery, Street Map, Topography
  • 3 parts Graphics
    • Graphical User Interface (GUI) and Mapping Tools



  • In a large Database: Stir Geographic Data with Tabular Information
    • Geocoding, Database Design, Make Event Layers
  • Select a non-stick User Interface and press Basemap evenly into the Corners



  • Preheat the GIS toolbox to Automate Tasks using Models or Scripts
  • Divide Data mixture evenly into Feature Layers
  • Sift and Fold the Feature Layers into Geoprocessing and Analysis tools
    • Perform Analyses, Generate Statistics, and Analyze Networks


Finishing Touches

  • Glaze with Thematic and Map Elements to tell the Story
    • Symbols, Labels, Layout, Legend, North Arrow, and Scale Bar
  • Trim excess and Overlay Layers
    • Demonstrate Statistical Hotspots and Illustrate Spatial Patterns
  • Cool the map on a Web Server for Publishing
    • Interactive Maps highlight Spatially and Temporally Dynamic data
  • When baking at a high altitude, use Custom Widgets to show Data Trends
  • Decision-makers see Correlations and answer Complex Questions


(this image was too cool not to post! source:


I would love to hear what y’all think about this and would love to hear of anything I should add/take away from this as well. I can continue to update it.  


title Image source: