NASA’s Parimal Kopardekar, a key figure in the field of advanced air mobility (AAM), recently highlighted the need for alternative position, navigation, and timing (PNT) systems to support GPS in autonomous aircraft. AAM encompasses various systems, from piloted aircraft to fully autonomous air taxis, and the reliable tracking and location of these vehicles in urban areas is crucial.
According to Kopardekar, there are urban locations where GPS signals are unreliable or not available due to factors like multi-path error. As a result, NASA is working with various companies to identify and define the requirements for alternative PNT systems. The agency is not developing the technology itself but is focusing on establishing the necessary operating requirements.
Potential solutions could include satellite-based systems, ground beacons, or a combination of different technologies. NASA is collaborating with both traditional and non-traditional aviation companies, such as Higher Ground and NextNav, to explore these alternatives.
NASA’s AAM Mission unit, established in 2020, aims to facilitate the safe development of air transportation systems for emerging aviation markets. While NASA has an ambitious schedule for AAM with piloted systems expected to be operational sooner, the agency recognizes that reliable positioning is particularly critical for autonomous or remotely operated vehicles.
The FAA’s Advanced Air Mobility Implementation Plan, released in July, projects the operationalization of AAM systems or a system by 2028. Collaborative initiatives like Innovate28 (I28) are driving the development of an integrated AAM ecosystem across key locations.
During the AAM Summit, another participant, Erick Corona from Wisk Aero, highlighted their solution for alternative navigation. Wisk plans to use a redundant, multi-source positioning approach, such as a tightly-coupled inertial navigation system (INS), to ensure the safety of their air taxis in the event of GNSS outages. They have partnered with Safran Electronics & Defense for their sixth-generation air taxi to supply the SkyNaute INS, which is based on Safran’s patented HRG Crystal Hemispherical Gyroscope technology.
Overall, NASA’s exploration of alternative PNT solutions aims to address the challenges associated with GPS reliability in AAM operations, particularly in urban areas, and ensure the safe and efficient movement of vehicles in the future airspace.