As concerns around Global Navigation Satellite System (GNSS) jamming and spoofing grow, engineers are rethinking how autonomous systems operate without external positioning signals. Here, Ross Turnbull, Director of Business Development at custom IC design and supply specialist Swindon Silicon Systems, discusses the growing role of inertial measurement units (IMUs) and how application-specific integrated circuits (ASICs) are supporting performance in navigation-critical platforms.
This shift is reflected in wider defence policy. The United Kingdom’s Strategic Defence Review 2025 placed autonomous systems at the centre of future capability, backed by “more than £4 billion” as a part of a wider investment across uncrewed and autonomous technologies. As defence and industrial sectors prioritise resilience in contested and signal-denied environments, technologies that can maintain accurate positioning and navigation independently of GNSS are becoming increasingly important.
The role of inertial sensing
For years, IMUs operated largely in the background as supporting components for navigation and stabilisation. Today, they play a critical role in autonomous aerial systems, robotics, industrial automation platforms and other applications where reliable positioning and motion sensing are required.
An IMU uses a combination of accelerometers and gyroscopes to measure linear acceleration and angular movement, typically across three axes. Many systems also incorporate magnetometers for heading correction. Together, these sensors provide the motion data needed to estimate orientation, direction and movement in real time.
In most modern navigation architectures, IMUs are used alongside Global Navigation Satellite System (GNSS) inputs in a complementary configuration. GNSS provides long-term absolute positioning, while IMUs provide short-term motion tracking and continuity between updates. In this arrangement, GNSS corrects IMU drift, while IMUs bridge gaps when external positioning signals are unavailable or degraded.
In high-reliability autonomous systems, however, the challenge is not simply generating inertial data. It is maintaining confidence in that data under harsh and highly dynamic operating conditions.
Modern microelectromechanical systems (MEMS) gyroscopes and accelerometers are compact, lightweight and power efficient, making them well suited to applications where size, weight and power consumption remain tightly constrained. However, their performance is heavily influenced by the quality of the surrounding electronics and signal chain, including analogue acquisition and signal conditioning.
Bias instability, thermal drift, vibration rectification error and electrical noise can all affect IMU accuracy, particularly during prolonged operation in challenging environments. Even relatively small orientation or positioning errors can accumulate over time and distance in autonomous systems.
Operating in challenging environments
This matters because IMUs are often used as primary navigation and control inputs rather than secondary reference systems.
When external positioning signals are interrupted, the IMU can support dead reckoning, motion tracking and continued system operation until those signals recover. In autonomous aerial systems, robotics and other navigation-dependent platforms, this continuity plays an important role in maintaining operational performance.
As autonomous systems become more capable, engineers are placing greater emphasis on the analogue front end, calibration strategy and signal conditioning architecture surrounding the sensing element itself. This is where mixed-signal application-specific integrated circuits (ASICs) are becoming increasingly important.
Mixed-signal ASICs allow developers to optimise analogue acquisition, filtering, calibration and digital processing around the specific characteristics of the sensing element itself. By integrating low-noise analogue front ends, signal conditioning and processing closer to the sensor, developers can improve signal integrity while reducing board-level complexity and susceptibility to electromagnetic interference.
As a result, aerospace, industrial and autonomous systems developers are moving away from generic interface electronics towards more tightly integrated ASIC architectures that also help reduce electrical noise and variability in IMU signal processing.
The silicon behind performance
The benefits are practical. Thermal compensation can be optimised more effectively for specific operating profiles, helping maintain sensing accuracy across wide temperature ranges and extended deployment cycles.
For manufacturers operating in aerospace, industrial and other high-reliability sectors, lifecycle support and long-term component availability also remain important considerations. Many systems are expected to remain operational for well over a decade, making reliability and obsolescence management key engineering priorities.
Swindon Silicon Systems has extensive experience developing mixed-signal ASICs for harsh operating environments where low-noise performance, reliability and long operational lifecycles are critical. That expertise is becoming increasingly relevant as IMUs move deeper into autonomous, sensor-rich and navigation-critical applications.
The next navigation challenge
Across aerospace, robotics and autonomous systems applications, development is increasingly focused on improving IMU performance, resilience and integration. Future advances are likely to involve tighter integration between MEMS sensing elements and ASIC architectures, alongside more advanced sensor fusion and edge-level processing.
For engineers developing next-generation autonomous systems, the question is no longer whether inertial sensing matters. It is how accurately and reliably IMUs can continue operating when external positioning signals become unreliable or unavailable.
For more information on mixed-signal ASIC development for sensor-rich and high-reliability applications, visit our website here.
