Thermal orthophotograh

By Andrew Starc

FAVOURITES – 4 May 2010 – Moonee Valley City Council, located in the area north-west of the Melbourne CBD, is in the early stages of using an aerial thermal imagery technology to help slash the heat and energy levels of buildings, parks and roads.

The technology, known as thermal orthophotography, is being provided by Perth based company Digital Mapping Australia, which uses a light plane to take orthophotos that provide quick and accurate monitoring of temperatures within specifically defined areas.

According to the company’s director Bruce Mason the aerial imagery picks up reflective heat through airborne sensors attached to aircraft, providing a snapshot in time, revealing the specific temperature variations between individual buildings, parks and roads.

The company has already taken thermal orthophotos of various sites in Perth, Sydney, Adelaide and Victoria.

Moonee Valley City Council’s senior geographical information system officer Michael Hakkennes says the council is in the early stages of using the technology as a key instrument in determining projects to reduce temperatures of buildings.?“Thermal imaging allows us to take snapshots of buildings and streets, see what their temperatures are from the colour thematic map of the whole area and then see which ones are the hottest,” Mr Hakkennes said.

“So far we’ve used thermal imaging for two projects, both concerned with planting vegetation in an effort to reduce heat. The first is to see which buildings are the hottest, then to plant vegetation next to those buildings. At a later date we take another thermal shot and see if the temperature has been reduced by the vegetation.

“The second project is to do with the amount of trees on roads, with the view of seeing if planting more trees on roads has the effect of cooling the road.

“We’ve also applied the technology to residential areas, with thermal imagery able to show the average temperature of particular buildings, identifying which houses are hotter than others, from where we can deduce whether temperatures vary because of different roof materials.

“We’re in the early stages of using this technology, [but] we’re hoping that in the next few weeks and months that we can analyse our results in more detail and see in what areas we can expand on the use of thermal imagery within our municipality.”

Mr Mason said that the temperature information gathered by the technology can provide an insight into the level of energy consumption of individual buildings.

“The information taken from these photos, like the temperatures of individual buildings, allows us to make deductions and produce a value added output of data, for example how much money a particular building is spending per square metre of building space,” Mr Mason said.

“A thermal orthophoto is a snapshot in time. Taking pictures at intervals, say 12 months apart, can allow us to identify changes in temperature. For example, if a building undergoes a retro-fitting, we can take before and after pictures and see if there’s been a change in the building temperature. With this information, the causes of temperature variations in buildings can be investigated. ”

What is perhaps most insightful about this emerging brand of technology, is its use as a monitoring tool, allowing councils or businesses to ask questions as to why a building is of a certain temperature.

“If we find out the temperature of certain buildings through aerial thermal imagery, and some of those temperatures turn out to be higher or lower than the temperatures of surrounding buildings, roads or parks, then we can start to ask questions as to why that is.
It gives councils [and or other clients] an opportunity to conduct on-ground checking, to see why a particular building’s temperature is at odds with its surrounds. This could reveal that there may be excessive use of air-conditioners, heating systems or other appliances.”