How to digitize maps

In a lay man's language, digitizing is the process of converting information to digital format, in this case maps. Digitizing converts raster data to vector data which can then be used for analysis this give various results. I am going to outline the process of georefrencing and digitizing using three common softwares which are ArcGis, QGIS, Grass and AutoCAD. In my future posts ibwiok also share Python scripts for these functions but it's not possible... By the time of writing this post... To digitize by just writing a Python script. Digitizing is a lengthy process is is very crucial for GIS and is better done manually.

HOW TO GEOREFERENCE IN ARCGIS

1. Start by creating a folder on the desktop or your preferred storage place and place your map that needs to be georegerenced.

2. Start ArcMap and add the map by going to the plus sign at the toolbar, connect to folder and access the map. The map will load in Arcmap.

3. Go to the georeferencing tools at the tool bar and select "add control points", go to a known location on the map, left click then right click, then input x and y which are the coordinates for the known location.

4. Do this for 4-6 points. Depending on the complexity of the data you are dealing with.


HOW TO DIGITIZE

1. After georeferencing the next step should be to digitize. The best way to digitize is to access the arc catalog from the windows dropdown at the tool bar.

2. Right click on your connected folder and create a new shapefile. This depends on the type features you want to digitize. They can take the form of lines or polygons or points.

3. Click on editor, start editing, select the control features and start digitizing.

NOTE
Georeferencing and digitizing can have some errors but we will discuss them in later posts and also how to rectify them. I will also share how to digitize and georeference using other softwares to cater for different peoples requirements and needs. If you enjoyed the post you can leave a comment below.

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