Drone Safety: Avoiding positional uncertainty
Page last updated:14 March 2025
The Challenge
Remotely Piloted Aerial Systems (RPAS), commonly known as drones, continue to gain popularity due to their versatility and utility across a wide range of industrial applications. In Australia and New Zealand, RPAS are increasingly deployed to assist with farming, remote health, environmental management, entertainment, emergency rescue and disaster relief. With the first commercial Beyond Visual Line-of-Sight (BVLOS) delivery services already occurring, drones are positioned to be a prominent facet in the future of logistics.
Alongside a rising trend of more frequent and widespread RPAS use, there is a growing demand for robust and dependable methods to monitor and manage their movements through airspace. This necessity has been demonstrated by past incidents where critical air services have been forced to divert during emergency operations due to the presence of RPAS in the vicinity. In the future, co-operative efforts involving both crewed and uncrewed aerial systems operating in close proximity will require improved situational awareness. Enhanced navigational technologies are key to realising these capabilities. Global Navigation Satellite Systems (GNSS) are commonly used to support a wide range of RPAS functions. Many RPAS used in industry already carry GNSS equipment, though this equipment may have limited accuracy.
Until recently, there has been a gap in capability for applications where very high accuracy is cost-prohibitive, but consistency and repeatability are a priority. Ensuring safe and reliable RPAS operations will require a high degree of trust in their positioning systems. This is made possible through GNSS augmentation. The Southern Positioning Augmentation Network (SouthPAN) is the first Satellite-Based Augmentation System (SBAS) in the Southern Hemisphere, providing real-time connectivity and enabling sub-metre accuracy in compatible devices across Australia and New Zealand.
The Solution
Quantum Systems’ Trinity Pro RPAS, utilising SouthPAN DFMC navigation capabilities in flight.
The Southern Positioning Augmentation Network (SouthPAN) is a joint initiative of the Australian and New Zealand Governments that delivers SBAS services across Australia and New Zealand, and their maritime regions. Geoscience Australia in partnership with Toitū Te Whenua Land Information New Zealand are leading the development, deployment, and operation of SouthPAN, the first SBAS launched in the Southern Hemisphere. Without correcting for common error sources, affordable GNSS systems are often limited in accuracy to around 5-10 metres. SouthPAN delivers corrections that mitigate these errors, improving positioning accuracy down to less than a metre.
By delivering corrections signals directly from a satellite, SouthPAN is able to overcome gaps in mobile, internet and radio communications. Early Open Services are now available, featuring real-time connectivity, and enabling sub-metre accuracy in compatible devices across Australia and New Zealand. SouthPAN provides users with open access to both L1 (the standard GNSS frequency) and Dual Frequency Multi-Constellation (DFMC) services, paving the way for improvements to the accuracy and dependability of RPAS operations, both in the short-term, and in the future. Through SouthPAN’s L1 Early Open Service, RPAS users can now monitor positioning integrity in real-time, helping them to ensure safer flights without reliance on mobile networks or additional ground-based infrastructure.
Open-access DFMC SBAS promises further improvements to navigation performance and integrity and provides resilience to ionospheric effects. DFMC SBAS services allow for seamless navigation throughout all of Australia and New Zealand, including challenging geographic locations for GNSS, such as those close to the equator and poles. DFMC will bring additional resilience, and further improve the positional certainty of the systems, providing pilots with greater situational awareness necessary to navigate congested airspaces and support safe cooperation between crewed and uncrewed aircraft.
The Impact
RPAS pilots using SouthPAN’s L1 service can immediately benefit from a reduction in positional uncertainty, giving them the confidence in their systems to safely tackle jobs in challenging environments. Relying only on the standard L1 GNSS frequency allows this capability to be utilised by a multitude of platforms, without any additional costs to the user.
Upgrading to SouthPAN’s DFMC service will bring additional resilience to ionospheric impacts, and further improve the accuracy and integrity of systems, unlocking the potential to operate multiple aerial vehicles in closer proximity, or within shared airspace with crewed aircraft. Preliminary testing using a fixed wing, Vertical Take-off and Landing (VTOL) drone, has shown up to 44% additional improvement in the positional certainty using DFMC over L1. Flight testing in Townsville, Queensland recorded an improvement in 3D accuracy from 1.6 m using SouthPAN L1, to 0.39 m when using DFMC.
With SouthPAN, RPAS operators can enjoy a wide range of benefits, including:
- Improved accuracy throughout all phases of flight, better supporting pilot aids and autonomous functions.
- Enhanced RPAS reliability, essential for coordinated traffic management between crewed and uncrewed aircraft within operational airspace.
- Real-time indications of navigational integrity, further enhanced through the DFMC service.
- Greater situational awareness due to minimised positional uncertainty, giving operators the confidence needed to conduct safe and compliant activities.
- Reduced costs by utilising open-access L1 and DFMC navigation services with coverage across all of Australia and New Zealand.
- Greater alignment with the navigational requirements imposed by the legislative standards of respective national aviation authorities.
- L1 SBAS operates using the standard frequency already widely supported by GNSS receivers and commercially available RPAS.
- DFMC SBAS services allow for seamless navigation throughout challenging geographic locations for GNSS, made possible by vastly reduced susceptibility to ionospheric effects.
SouthPAN L1 and DFMC services offer RPAS users a multitude of benefits, ranging from improved accuracy and reliability, to enhanced safety and regulatory compliance, facilitating seamless and efficient operations across diverse environments and airspace.