GISystem

May 18th, 2014

Creating school catchment zones with QGIS

A mess of classified streets

If you ever want to test a potential hire for a GIS position give them a task to accomplish using a different GIS system than that which they are familiar with. Having taught GIS for almost 10 years, it’s clear that those students who are capable simply read the documentation or do a search online for the best way of accomplishing their desired task. So presenting a potential recruit with a new GIS system will quickly reveal whether they are familiar with the concept of figuring things out on their own by searching online. Once you are familiar with the GIS concepts, any GISystem should be straight forward.

(more…)

November 5th, 2010

ArcGIS: Joining a Text File

Joining data in ArcGIS is a fundamental task for analysis. It allows database type joining operations in a versatile and simple manner. This process can however fail inexplicably, or so it seems, causing great frustration and anger.
(more…)

March 17th, 2010

Integrate Tool & Network Analyst

Network Analyst is a fun package to explore. It allows the calculation of much more meaningful distances than a buffer can accomplish. Of course with more power and potential comes more difficulty/buggyness and errors to be encountered. I was using ArcGIS’s Network Analyst (NA) extension to calculate the distance from residential blocks to various amenities using the ‘Find Closest Facility’ method. I was encountering significantly high failure rates – 90 percent of the blocks failed to find a facility.

(more…)

January 11th, 2010

Adding GPS points to ArcMap

One of the most satisfying activities when using a GIS is using your own data. Typically this is in the form of lat/long coordinates from a map or a GPS unit. The next step is to import the GPS data/coordinates into ArcGIS:

(more…)