A View From the Top

Craig Mahlasi Works as a Geographic Information System and Remote Sensing Geographer, Working With Data That Promotes a Fuller Understanding of the Planet

- Bruce Dennill

Remote sensing: for the layman, what does it involve?

Craig Mahlasi Think of it as a sort of solution to nearsightedness, bringing objects that are far away into focus. We use specialised cameras on spacecraft orbiting the Earth, which help us to see beyond what we can see down here. We see red, blue and green; the cameras see near infrared and beyond infrared colours that can be interpreted in different ways.

How are measurements taken, and what constitutes a good or bad reading?

The satellites and cameras are so good now that the possibility of a bad picture is minimal. There are two types of remote sensors – active and passive.

Passive sensors rely on external power. The sun is one source. It shines on the Earth and the cameras record the light that is reflected and then builds an image based on what comes back. All of that data is then transferred to a ground station – we have one in South Africa at Hartbeeshoek.

There, it gets stored and processed and made available to whomever needs it – which could be for free or at a cost. Then the analysis starts, with us trying to extract the most out of the image. Doing that requires innovation, and the differentiation that results from working in different ways in the field is the basis of how the business develops.

How does what you do impact the average consumer in real terms?

Remote sensing is also called ‘Earth observation’. NASA and other similar institutions put up satellites to benefit humanity in general, with obvious applications including the monitoring of weather patterns, like the recent cyclones in Mozambique.