The Exploration Place The Electronic Forest Living Landscapes

Photos need work before they make sense

A picture of Punchaw Lake with an overlay of dots marking areas where pine beetles have infested trees.

Before a satellite photo can be used, it is tied to fixed reference points.

Filters make items of interest more obvious. Here, for example, individual trees infested with mountain pine beetles are shown as yellow dots. Beetle-killed trees can be pinpointed because they first turn red, then grey. Red trees are easy to spot because trees in this area are generally green, with some turning yellow in autumn; red maples do not grow in the sub-boreal forest. Trees do not turn grey when alive, so a filter finds them easily too.

A satellite image makes it possible to identify affected trees and locate them within about 10 metres. A helicopter can be flown over the area to verify the satellite image and, using a Global Positioning System (GPS), identify more precisely where the affected trees are.

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