Lately, the news seems to be filled with talk of drones, whether deployed for military purposes, to help overenthusiastic paparazzi peek into the lives of celebrities or as a future logistics option for companies like FedEx, Amazon or Dominos Pizza.
You’d be forgiven for thinking that this emerging platform was a relatively recent phenomenon, but the truth is that these technologies have been used since the mid-1800s, when pilotless balloons bombarded Venice during the first Italian War of Independence. After the invention of photography, primitive aerial photographs were captured from balloons in the 1860s, and from tethered kites from the 1880s onwards.
A lot has changed since then - Remotely Piloted Aircraft (RPAs), Unmanned Aerial Vehicles (UAVs) and drones have moved beyond their original military applications and are carving out a niche in the science of remote sensing and mapping, while creating regulatory challenges for governments around the world. Australia was actually the first country in the world to begin to regulate RPAs in 2002, but advances in GPS, robotics, microelectronics and battery technologies continue to deliver new choices for consumers and new demands on regulators to keep the sky safe.
But how does the state of the art in RPAs stack up against what is possible from the Spookfish aerial platform? Why don’t companies like Spookfish abandon expensive aircraft and operate low cost drones instead? I’m glad you asked – let’s see what they have in common... and where the critical differences exist.
Both platforms are capable of capturing high resolution (sub-5cm) orthophotos, Near Infrared, 3D models and elevation data, at high levels of positional accuracy without the need for ground control. Both platforms can include automated processing of captured imagery, which enables users to access the data very soon after capture. And both platforms require specialist software to plan flight lines over survey areas to ensure sufficient overlap of images to provide accurate geo-referencing.
Operationally, the Civil Aviation Safety Authority (CASA) impose a very different set of restrictions on RPAs when compared with the well-established air traffic control regime that aerial operators like Spookfish work within. RPAs must be kept more than 30m from people, vehicles, boats and buildings and cannot fly over crowds or higher than 400ft (122m). They must also stay away from aircraft, remain more than 5.5km from aerodromes and be kept in line of sight by on-ground operators at all times. It is also illegal to fly commercially unless the pilot has a CASA-issued unmanned operator’s certificate.
In terms of imagery data acquisition, most RPAs used for remote sensing have a payload capacity of a few kilograms, in-air endurance of around 15 to 45 minutes per flight and can capture data of around 5-10km2 with a single camera. This means a typical day of RPA surveying might cost around $5,000 to $7,000, involve 3-4 flights and capture data over areas up to 40km2. Whilst larger drones exist, their size, weight and complexity results in high numbers of ground crew being required, making them much costlier to operate than traditional aircraft.
This makes RPAs useful for bespoke, small area use cases, like mining volumetrics, irrigation design, earthworks projects, noise modelling, dam design and catchment mapping, and localised vegetation mapping, where the project requirements (for example, capture at a specific time on a specific day), do not fit into a larger capture program. These use cases can pose problems for safely landing the RPA, particularly in the rough terrain of Australia’s remote areas…but those landscapes don’t tend to feature in promotional videos filmed on the flat, grassy plains of Europe!
This contrasts sharply with the higher performance camera system and multi-hour flight time of aerial platforms, which in the case of Spookfish enables the capture of data over tens of thousands of square kilometres a day, at costs of only a few dollars per km2.
The bottom line? Advancing technology will continue to open up exciting applications for RPAs, but for the foreseeable future, RPA capture will be limited to very small areas which, although tailored to meet bespoke requirements, are still comparatively expensive and less convenient compared with Spookfish.