Keeping Radar Systems Alive

“We Humans Are A Complex Interwoven System Of The Body, The Mind, And The Spirit. We Are Formed And Informed By The Interplay Of These Systems.” (Ann Scott, French novelist ).

You may not realize the importance of each part of your “System Of The Body”, until your little finger, your knee, back or any other part of the system gets hurt and maybe even immobilized for some times. As any system, a body is aging, one has to take more rest, take more care for health, and some functions and the overall wellbeing will almost certainly degrade over time. Each of us understands all this when it is about human health. However, what about a technical system that has to last decades, has to suffer sometimes from physical or environmental stress, and that is still expected to perform as at a younger age despite of the hours of operation in a sometimes changing environment?

Defence systems are designed to fulfil their role over a long period of time and are becoming more and more complex, connected, and intelligent. They are built using proven, reliable and scalable technologies. Sensors are a critical part of these technologies as they provide the “eyes” to the defence ecosystem, including complex controls, measurements, and monitoring. Sensors are used in flight controls, propulsion, environmental monitoring, weaponry controls, indicators, communication systems, etc. Here I want to focus on radar sensor systems only.

Radars are active electromagnetic sensors that are used for detecting, locating, tracking, and recognizing objects of various kinds at large distances. A passive radar operates by transmitting electromagnetic energy towards a target and observes then the echoes returned to the radar. The targets may be aircrafts, drones, ships, any kind of vehicles, or missiles. Multiple calculations using the reflected echo allow then to identify size and shape but also location, direction or speed of the target. A basic radar system uses a transmitter that generates a high-power signal. The signal then is radiated by the antenna, a duplexer enables alternate transmission and reception with the same antenna; and a receiver selects and amplifies the radar echoes. A signal processor separates the signals reflected by possible targets from unwanted noise and clutter. Based on the information provided, a decision can be taken whether a target is present or not. The track of the target can be obtained by measuring the target location at different times. The target coordinates are shown on a display and action can be taken.

Image: Key elements of a radar system ? Thales

Radars are designed to last sometimes many decades. The environment the radar operates may be evolving (e.g. windfarms), there can be new challenges (e.g. drones) or new legislation (e.g. operator safety). As with the human body, one needs take care for each element of the radar to make sure the expected system performance can be achieved over time. There are some key pain points to be considered, may it be during maintaining, overhauling or upgrading an existing defence radar:

1.??????Keep it working

The first challenge when extending a product’s lifecycle is ensuring basic functions for the additional time it needs to operate. This requires product lifecycle roadmap planning that involves internal (make) and external (buy) product and software dependencies. Life extension programs can help anticipate potential aging of components or addressing obsolescence issues. A specific case is fatigue. Older radar generations include mechanical parts that can be subject to fatigue. Traditionally parts concerned by fatigue are replaced under preventive maintenance programs.

2.??????Old products meet new requirements

Upgrade programs can be extremely complex. New parts and tools may be introduced; software may need to be updated. Modern capabilities of instrumentation, simulation and computer monitoring have often been developed years after these defence radars have entered service. Such tools are constantly improving. In some cases, data is already available in the system, but also new monitor capabilities may be added to measure for example external temperatures, vibrations or humidity so that the impact of system or environmental conditions on the system health can be predicted. Data analysis and planning tools can improve the radar system availability. These supporting capabilities and software can and should be retroactively introduced during a life extension programme to provide maintainers and operators with the tools to track, analyse and manage the radar system performance.

3.??????Spare parts availability

Maintenance teams need the right part in the right place at the right time. Ensuring this performance down to the last bolt requires a full view of the supply chain. With the advanced age of some radar systems, spare parts availability becomes critical and maintenance schedules may be at risk. Due to the age or small volume, some suppliers cease trading and the supply chain becomes less reliable. With spare parts no longer available from the same sources, this often leads to building internal repair capabilities or additional investment for finding and qualifying new sources. Sometimes creative approaches using specialized websites for obsolete spare parts or buy-back initiatives where spare parts are bought from customers may allow providing a solution, but this is limited to smaller quantities and these parts still need verification to guarantee quality standards are met.

4.??????Scarce resources - skill transfer is a must

As equipment ages, so do the maintenance engineers who keep them operational. Declining transfer of knowledge means a large proportion of key maintenance processes are at risk of being lost. To avoid this potential skills gap, anticipation of departures, but also a systematic approach towards digitalization of knowledge (documentation, videos, augmented reality…) is necessary to bridge the gap. Incorporating maintenance history into maintenance systems ensures that the lessons learned stay learned and component history can be tracked along the lifecycle. Modern tools also help making the maintenance work more attractive for younger generations of maintainers.

As discussed in the key pain points above, delivering services over long lifecycles can be a challenging undertaking. All parts of “System Of The Body” are concerned and many potential health risks have to be addressed, one by one. The imperative to improve conditions, cost effectively manage radar systems over their whole life, and conserve limited resources are addressed by lifecycle planning. Lifecycle planning allows ensuring the efficiency and availability, at the required performance level for your mission-critical radar systems.