Frequently Asked Questions

The North Australia and rangelands Fire Information service (NAFI) is centred around this website which aims to help land and fire managers across the open country of north Australia and the rangelands better manager fires. It does this by distributing regularly updated maps of burnt areas and active fires tailored to the needs of people who manage fires in this open country and who want to manage country as well as controlling wildfires.

NAFI is a non-profit unit based at Charles Darwin University with staff in the Northern Territory and north Queensland. It draws on the university’s world class research on fire management and its focus on science and objectivity.

NAFI also provides tools and other mapping based on this hotspot and burnt area mapping to help people manage this open country. We create multi-year fire history maps that help with planning, and we have reporting tools based on this fire history that help people measure progress in their fire management.

The NAFI team also run workshops with users to help them get more out of NAFI.

“Hotspots” (locations of active fires) are automatically detected by overpassing satellites that detect bright/warm points in the landscape. Most of these satellites are moving across the sky capturing images of fires on the ground as they pass overhead - the images are then beamed down to a receiving station.

A computer algorithm identifies the “hotspots” in the satellite image and their locations are sent to the NAFI website and displayed on a map. There can be many thousands of hotpots detected each day at the height of the fire season and an automated process is the only practical way to go.

There are two types of hotspots displayed on NAFI:

• Regular Hotspots with a location accuracy between around 375m – 1km sourced from the overpassing satellites. With half a dozen or so of these satellites passing overhead at particular times of day, the hotspots updates appear in clusters: in the late morning, in the mid-afternoon, late in the evening and in the early hours of the morning.
• 10-minute Hotspots sourced from a Geo-stationary satellite that sits above Australia and provide updates every 10 minutes, but this satellite is at a very high altitude and has a location accuracy of a few km and tends not to detect smaller fires.

• The satellites orbit above the cloud layer and the hotspot sensors cannot see through clouds – so fires that have clouds between them and the overpassing satellite will not be detected. In northern Australia the main fire season from April/May – November/December tends to have less cloud cover and most fires are detected.

• The computer algorithms used to pick out hotspots can only identify the heat/brightness signals that an active fire produces. In the great majority of cases these are active fires, but not always. Hot rocks, hot pools, hot smoke, chimney stacks and small gaps in clouds can also trigger a hotspot identification. Sometimes sensor errors can produce lines of false hotspots or hotpots in shifted locations. Where such errors are detected, we remove those hotspots.

• Unlike hotspots which record the passage of fires across the landscape, burnt area mapping records the impact these fires have on the landscape: the area burnt and the time it was burnt. These burnt areas are also mapped by examining satellite imagery – in this case to see where areas show signs of being recently burnt with blackened areas that were not seen in previous images. The date of the burn can only be narrowed down to the time between the latest satellite image showing the burn and the most recent image showing no burn in the same location.

• Because the burnt area maps are a permanent record and are used to create multi-year fire histories which are used in property planning and emissions estimation, they need to be accurately located right across the mapped regions. An automated process is used to create the initial burnt area mapping but to get the required accuracy they are then manually edited by NAFI mappers.

There are two main types of burnt area mapping displayed on NAFI with different location accuracies depending on the satellite imagery used:

• Moderate-resolution burnt area mapping with a location accuracy of 250m – each map pixel is the size of a sporting arena. This mapping covers much of the open country of Australia and is updated weekly in areas with frequent fire.
• Finescale burnt area mapping with a location accuracy of 10-20m – each map pixel is the size of basketball court or less. As accurate finescale mapping requires more resources, this mapping covers smaller regions in the far north where demand is high, and end-users pay for this mapping.

• The satellite sourced maps of hotspots and burnt areas are more reliable in the broad, open landscapes of north Australia and the rangelands. They are not as reliable in effectively capturing the smaller, fast-moving intense fires that occur in southern cropping lands, forested country and more populated areas. So these areas of south-western WA, south-eastern SA, Tasmania, Victoria, and eastern NSW are masked out.

• Western NSW and the Victorian Mallee are open country but tend to have smaller fires that ae not well captured by the standard NAFI mapping and hotspots, so these areas are also masked out.