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Tiana Warner
Technical content marketing at Safe Software
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About FME    |   August 1, 2014   |   By Tiana Warner

CAT to GIS: Tracking Cats via GPS on Google Earth

Where do cats go when they’re outside all day and night? What do they do? How do they entertain themselves? Is there a secret cat meeting place in every major city? When Safers found out about Cat Tracker, we couldn’t resist. This science project is dedicated to tracking your cat’s GPS locations to find out exactly where little Catniss goes on her midnight prowls.

GPS Cat Tracking data when sent through an FME Workspace and output to KML

GPS Cat Tracking data when sent through an FME Workspace and output to KML

FME Can Haz Cat Tracking

The FME Workspace used to read and transform Movebank’s animal tracking data

The FME Workspace used to read and transform Movebank’s animal tracking data

The cat tracker data comes from Movebank, a free online repository of animal tracking data. The GPS datasets are provided in JSON format, which Aaron was able to download and extract using a few FME transformers. Flattening the JSON creates attributes, including latitude and longitude, which the FME Workspace then geocodes, transforming the data into spatial features.

GPS anomalies can be handled using QA / data validation

GPS anomalies can be handled using QA / data validation

Creating a convex hull around the points gets the cat’s “prowling area”. You might notice a few outlying points in the dataset, where the cat seems to travel a huge distance quite suddenly. Is this a burst of speed and energy? A car ride to the vet? Kitty teleportation? More likely, it’s just a GPS anomaly, and these can easily be removed with data validation. Next, the cats are ranked based on the size of their travel areas. The locations are then sent through an algorithm that calculates each cat’s average velocity using the distance between the points and the difference in their timestamps. This is also sorted and ranked by average. Finally, the top speed for each cat is determined, and the output sent through a few KML styling transformers.

Try it yourself

Download the workspace and output data, and be sure to open the KML file in Google Earth for the full experience. Trust me, you’re going to want to browse this data.

Chemistry Cat approves of this valuable contribution to science

Chemistry Cat approves of this valuable contribution to science

If you’ve transformed any weird and interesting data with FME, I’d love to hear about it. Send me a note or leave a comment!