Meet Pearson’s retiring map maven
For more than two decades, Cathie Tonkin has kept tabs on every inch of the airport as its resident mapmaker.
Cathie Tonkin has a kind of X-ray vision when it comes to Pearson. When she looks out at the airfield, she doesn’t only see concrete and painted markings like the rest of us. She can also visualize the kilometres of electrical wiring beneath the surface, the fuel lines, the stormwater pipes and countless other pieces of infrastructure hidden from view.
As a Supervisor of Engineering Data Operations and the airport’s first mapmaker, for the past 27 years Cathie has studied every inch of Pearson, above ground and below. She has kept tabs on the underground utilities, the surface features, the topography and alterations inside the buildings. If it has changed, moved or been redesigned in the past two decades, Cathie knows about it.
As she retires, we caught up with Cathie to find out what it means to be an airport cartographer and how she got into mapmaking in the first place.
Why do we need so many maps of the airport?
They’re used for all sorts of reasons. For instance, in early spring, maintenance starts trimming the grass, so I’ll create maps that guide them where to cut and at what lengths. Then in fall, I’ll create maps for snow removal, so the plow drivers know which routes to follow to clear the runways and taxiways. I also make a lot of maps for the security team and emergency services.
How do you keep your maps up to date?
Our department flies low-level aerial photography every other year to create high-resolution images of the entire airport, which we use to update our data sets. We also send survey teams to map changes in the underground utilities, because we can’t see those from an aerial photo.
Why don’t you use Google Maps like the rest of us?
The resolution isn’t good enough. We need to be able to find things as small as a manhole cover or a light on the runway and position it on our maps to an accuracy of a few centimetres. Services like Google Maps are better than they used to be, but when you try to drill down to that level of detail, they become a blur of pixels.
How did you get into cartography?
A teacher suggested it to me when I was in Grade 12. I didn’t even know what a cartographer was back then, but I liked geography and I liked to draw. I found a college course, and I just fell in love with it.
How has mapmaking changed over the years?
When I started, everything was hand-drawn in ink or using scribe coat, which is plastic with a very thin layer of powder on it that you’d scratch off the surface. Today, it is all on computer and we have software like GIS [Geographic Information System]. But you still need the cartographic part. There are all sorts of rules to maps – like directions and sizes of text – and you have to think about what the best approach is depending on the content and what the user needs to see. That’s what I love about it.
You must know the airport better than anyone.
Yes and no. The other day, the airfield maintenance guys took me on a runway inspection, and I was lost. I could only figure out where I was by visualizing what it would look like from above. I’ve spent my life looking down at the airport, I couldn’t get used to seeing it another way.
What’s your favourite map you’ve made?
It was one I created for Howard Eng, the former GTAA President and CEO. He wanted to see where the population densities were in Ontario and the existing transportation networks – airports, railways and roads. It required gathering geographic data from various sources, population statistics and combining it into one useable map. That was a unique challenge.
Any plans for your retirement?
I’m going back to playing the piano. I have an old one and I don’t know if it’s completely in tune, but it’ll do the job.
