In addition to UAVs and satellites, conventional aircraft can also be used to capture highly detailed aerial imagery in order to enhance urban planning and analysis.
While much is being made about the potential of unmanned aerial vehicles (UAVs) to improve monitoring and reconnaissance of infrastructure and other built assets, aerial surveillance from conventional planes using readily available camera equipment is already transforming the way we view and analyse our urban environments.
According to James Rabey of nearmap, the use of high-end camera technology for aircraft-based surveillance can capture highly detailed aerial imagery in a manner that confers distinct advantages compared to UAVs or satellites.
“The aerial camera system that we’ve developed employs high-range off the shelf cameras, which we then use to survey large parts of Australia’s populated areas,” Rabey said. “Because the surveillance is performed from planes, we can capture a large amount of area much more quickly than we could from drones.”
The use of planes facilitates the comparatively rapid surveillances of huge swaths of land, enabling image providers to capture detailed information on populated areas.
“In the United States we’ve captured around 60 per cent of populated areas,” said Rabey. “In Australia, where we’ve been running a lot longer, we’ve captured around 85 per cent of these areas.”
In addition to permitting the rapid capture of aerial images covering sizeable surface areas, the technology also provides far more detailed imagery than the satellites that conduct surveillance of the earth’s surface from far higher altitudes.
“What makes this technology different is the high resolution,” said Rabey. "It’s five times greater than the sort of satellite imagery that is usually made publicly available, so compared to what you can typically get publicly, it's definitely got the highest resolution.”
A further advantage of aircraft-based surveillance is the regularity of updates, which enables planners to access timely and accurate information on urban environments that would be impossible to obtain via on-site terrestrial surveys.
"We cover most of the major towns and cities in Australia on a fairly regular basis – all the capital cities we would do at least six times a year,” said Rabey.
“The important thing to remember is that when you talk about urban development, it isn’t finished when the suburb’s been built, or the last house is built.
“From that point on the owners themselves continue to engage in urban development as the area grows in size and maturity, so it's important for council to have access to regularly updated information.”
Joseph Kaspar, a postgraduate researcher from the University of Melbourne, points to the importance of having access to timely and detailed aerial imagery for the purposes of urban planning and analysis.
“Aerial imagery possesses higher resolution than satellite photos, and is also available at more regular intervals, with companies like nearmap providing updates on a monthly or bimonthly basis,” he said.
“Regularity is very important. What I do with the University of Melbourne is look at tree cover in urban areas. If we wanted to examine this using satellite imagery, we’d use Google Maps, which is the standard platform, and perhaps only have access to image data that’s four years or five years old.
“But with nearmap we’ve got far more images, so over a five-year period, for example, you can see if zoning laws have encouraged buildings in areas and whether or not that’s decreased tree cover. We’re looking at this see if we can help councils understand what’s going on with tree cover, which has huge implications for a whole range of environmental and health factors.”
In addition to the provision of detailed imagery that is updated on a far more frequent basis, Rabey notes that in-built software tools enable engineers, builders and urban planners to engage in detailed analysis of the features of landscapes or the built environment based on aerial reconnaissance.
“We have a number of tools that allow you to then perform measurements – for example you can estimate the volume of soil that you may need to excavate, and then use it to determine how many trucks you will need to move,” he said.