Saturday, March 10, 2007


During the past two-weeks I have been teaching my post-graduates about geographical position, latitude and longitude, degrees, minutes, seconds, and decimal degrees. It might seem very easy to seasoned geo-informatics practioners, but students were finding it a little difficult. The problem surfaced when I expected the students to make different sized boundary boxes around a central point to insert some of our OGC web maps.

Well, help is on the horizon with our Geo-calculator which I have put into the sidebar on the right-hand side. This Java-script will convert both Degrees, Minutes, Seconds to Decimal degrees and the vice versa. I have made provision for calculating both Latitude and Longitude independently so you can simply insert these co-ordinates in Google Earth and add a negative to the value if you live in either the Southern or Western hemispheres to navigate to the exact site. To illustrate how you can use the geo-calculator, I will give you the co-ordinates to the entrance of our Ecology and Informatics Lab at the University of the Western Cape, South Africa.

Longitude 18 37 36.1
Latitude -33 55 53.4

You should type the degrees minutes and seconds with a space between each of them and then hit the calculate key to get decimal degrees calculated as follows.

Longitude 18.626694
Latitude -33.931500

Now type these co-ordinates into Google Maps, remembering to put Latitude first and then Longitude. Hope you find the Geo-calculator useful! Enjoy.