The story from above: Expanding our coverage footprint
Jun 2021
High-resolution aerial images captured by Nearmap cover 90% of the population in Australia, spanning more than 130,000 square kilometres.
Jun 2021
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Since Nearmap began capturing aerial imagery in 2007, our technology and capabilities have taken flight, and will continue to do so with our dedication to ongoing innovation and development.
As Director of ANZ Survey Operations at Nearmap, I’m responsible for ensuring we cover the areas that need to be photographed, and make the most of when everything aligns to make it possible.
Aerial image capture program overview
We only use fixed-wing aircraft to capture the truth on the ground — which includes Cessna 210s, Cessna 310s, Cessna 404s and Vulcanair 68 models. These steady workhorses generally fly at altitudes between 8,000 and 18,000 feet. For perspective, the cruising altitude of commercial jets is normally around 30,000 feet.
Flying at those altitudes with our exceptional camera systems enables us to achieve the level of high-resolution aerial image clarity we aim for with every flight – a ground sampling distance (GSD) of 5.5cm-7.5cm per pixel.
We create, manufacture and own the entire process from end-to-end (except the planes), including the design and manufacture of onboard hardware, the patented camera systems, the software to process the images, and our own flight plans, mapped carefully so as to combine the perfect balance of efficiency and coverage.
On average, a single flight lasts around four hours. Each flight takes thousands of photos — amounting to more than 500 million photos every year. A number of factors have to come together for us to be able to capture successfully.
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Takeoff clearance challenges
The challenges we face when planning flights include the weather; we need clear skies, no visual obstructions like clouds, fog or smoke. Seasonal climates can also present challenges, especially with cloud and rain in sub-tropical regions during the wet season, or the southern regions mid-winter.
Just like the equipment on board the aircraft, our flight plans are all about precision. Our pilots have to directly follow, and maintain, the GPS-guided flight-plan. Turbulence can affect their ability to remain directly on course, so clear, turbulent-free skies are needed for the pilots to be able to skilfully compensate for roll, pitch and yaw. If the sun is below 30 degrees in the sky, we will wrap up our capture, to avoid long shadows in photos. With Nearmap, it’s all about the detail.
The crucial underlying factor behind flights in controlled airspace is the need for clearance from Air Traffic Control — different locations have different air space restrictions, and we must work with those requirements. We fly 364 days a year: the only day we know our cameras are going to be on the ground with their shutters closed is Christmas Day.
A brief glossary of terms
A flightmap is a section of area that we cover, and it is the boundary of the aerial ‘footprint’ that our pilots follow. Our coverage areas are broken down into survey regions. For example, in Australia, we cover 118 different survey regions between one and six times per year, with population density a major factor determining capture frequency. These survey regions can be broken into several flightmaps, depending on the overall survey region size and shape. There is no standard size or shape of a flightmap, each is uniquely designed for the most efficient flying for our aircraft and systems.
2021 aerial map capture program update
We recently completed captures along the Queensland and West Australian north coasts – up to Cairns in QLD and all the way up to Broome in WA. These are two areas that can be tricky to capture due to their tropical latitudes and heavy rain or turbulent conditions during the wet season.
Since those first captures in 2007, we have expanded our coverage considerably.
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In 2020, the number of flightmaps published decreased marginally due to bushfires and COVID-19 restrictions which resulted in slightly fewer areas captured than originally planned. We have introduced 19 new areas into our Oblique/3D program, including NSW the Central Coast, Blue Mountains, Cessnock, Port Macquarie, South Coast and Southern Highlands; in VIC, Ballarat VIC Bendigo, Broadford, Bunyip, Calder, Melton, Mornington Peninsula, Seville, Torquay and Traralgon; in WA, Bunbury and soon, Toowoomba in QLD.
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Our Australian capture program covers 90% of the population, spanning more than 130,000 square kilometres across 118 survey regions; our oblique and 3D content (including DSM, DTM, Point Cloud and True Ortho) covers 77% of Australia’s populated areas, in 32 survey regions across 42,000 square kilometres.
In New Zealand, our program captures 73% of the population, in 14 survey regions across 11,450 square kilometres.
And in the US, we capture 70% of the population, over 700 urban and regional areas encompassing more than 878,000 square kilometres (339,000 square miles).
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What I do every day is pretty unique in terms of a job description, and I wouldn’t trade it for anything. Well, maybe some days I do wish I could be in the pilot’s seat seeing the world from above – but being one of the first to see the incredible images we capture when they come back after processing is something that makes every day a new discovery.
To learn more about the Nearmap coverage program, visit our aerial map coverage page.