GROW HOUSES 'EASY TO PICK OUT'

Forward Looking Infra-Red (FLIR) cameras mounted on police helicopters
produce images of people and objects that are invisible to the human
eye by measuring heat or thermal radiation. In scientific terms, such
radiation is produced by the movement of atoms and molecules.

It is measured as infrared wavelengths which are part of the
electromagnetic spectrum.

The Wescam FLIR cameras mounted on the bottom of York Regional
Police's French-made Eurocopter EC120-B capture infrared images of the
land's surface from a height of more than 300 metres.

Mike Boris, of the York Regional Police air support unit, says various
temperatures are captured as different colours. "A lawn is colder than
a person," Boris explains.

Boris said the helicopter's infrared cameras typically captures images
from "10 to 20 houses at a time" as the chopper flies over a typical
subdivision.

Boris said marijuana grow houses are "easy to pick out" because the
heat needed for plant growth rises to the top of the house and
infrared cameras see it as a hot spot in the centre of the roof's peak.

"A substantial marijuana grow will stick right out," he
said.

Boris said the infrared cameras measure surface heat and cannot see
through walls, or into homes and vehicles.

The helicopter is liked by police because its unique tail rotor makes
little noise, Boris said.