Digital Mapping Workshop Part 1

From text to map

Behind any beautiful digital map lies the reality that every point, line or polygon is generated by some form of numerical and textual data. Here is an example of a “placemark” written in KML:

<Placemark>
	<name>Visualization Portal</name>
	<description>Don't fall asleep! Data is fun!</description>
	<Point>
		<coordinates>-118.44339036032716, 34.069750838829485</coordinates>
	</Point>
</Placemark>

A few more options…

<Placemark>
	<name>Visualization Portal</name>
	<description>Don't fall asleep! Data is fun!</description>
	<LookAt>
		<longitude>-118.44339036032716</longitude>
		<latitude>34.069750838829485</latitude>
		<heading>45</heading>
		<tilt>50</tilt>
		<range>500</range>
	</LookAt>
	<Point>
		<coordinates>-118.44339036032716, 34.069750838829485</coordinates>
	</Point>
</Placemark>

History mapped

A paper map can be scanned and made digital. As an image, it does not know “where it is”, in terms of its spatiality. A process called “georeferencing” allows us to “spatialize” printed documents, and put them in the context of other spatial layers. Here is an example of one of the most famous historical maps, the “John Snow Map” from 1854 that illustrates a Cholera outbreak that attacked London.