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Get Actionable Insight into EW and Radar Performance
June 8, 2021 Blog

Authored by: Nancy Friedrich, Aerospace & Defense Industry Solutions, Keysight Technologies

Radar and electronic warfare (EW) systems exist in a never-ending battle to dominate each other. When a radar appears to an EW system, the EW system should evaluate it and potentially reprogram itself in a fast manner to defeat that radar threat.

From the radar system point of view, the goal may be to verify that it can mitigate newer cognitive jamming or EW capabilities. As a result, their goal is to verify that EW systems cannot successfully launch an electronic attack against them.

For both types of systems, simulating and recording these scenarios in the real-world signal environment offers a clear view into the systems’ responses and, ultimately, the outcome. Understanding how your system was defeated will help you make changes to your system so that it prevails in the EM spectrum environment in the future.

Spectrum Challenges

To prove the performance of mission-critical radar and EW systems, developers increasingly face test limitations in terms of both cost and time. Yet radar and EW systems must overcome growing challenges to optimal performance, as they operate in the increasingly crowded, unpredictable electromagnetic spectrum operations environment (EMSO). The radiofrequency (RF) spectrum grows only more congested as intentional aerospace defence systems intersect with many potential interferers, such as terrestrial broadcast signals and cellular and satellite communications. At the same time, modern threats and countermeasures flood the modern EM spectral environment with thousands of emitters, including radios, wireless devices, and radar transmissions. This, in conjunction with advanced digital signal processing (DSP), creates a dramatically complex EM spectrum. By recording their system’s performance with evolving radar recording capabilities, it is possible to gain crucial information to validate both EW emitter and radar systems.

Burden of Test

When it comes to EW and radar systems, the testing process is exhaustive and expensive. Range testing a new fighter jet, for instance, demands a large investment. By limiting testing time and then closely evaluating a recording of that testing, it is possible to verify that you attained the measurement of interest and verify the response to it – whether you are validating that the system did respond properly or verifying that an improvement needs to be made.

For radar systems, it is essential to detect anything in the environment – unintentional or intentional – that presents as noise-like to the radar. By recording the EMSO environment in those dense environments while you are testing your radar, you can see:

  • Did my radar work correctly?
  • What else was present in that environment when it worked right or did not work correctly?
  • How does the radar respond in a given scenario?
  • How is the radar system performing over time?

This knowledge provides confidence in radar performance in the presence of both intentional and non-intentional interferers.

Validating EW Emitters

Similarly, electronic warfare emitter validation is critical to know how your systems will perform in the EM spectrum environment. Increasingly wider bandwidths and agile signals continue to emerge, complicating this task. Emitter validation demands quantitative verification and validation from an intentional stimulus in the lab, such as an anechoic setting. The goal is to capture enough signals of interest over a diverse range of frequencies. Longer simulation and overall technique times need to be evaluated over a longer frequency range and bandwidth.

The goal of such validation is twofold: acquisition and analysis. The priority in terms of acquisition is being ready to record – having overall system simulators and the device under test ready and coordinated for the overall scenario. The focus is on assuring that the correct scenario is being transmitted and received at the correct time in order to not waste lab time. In contrast, the analysis aspect is more concerned with examining the recorded data in detail for proper simulation, stimulus, reaction, etc. Through this process, the goal is to gain knowledge around points like:

  • Will the platform correctly operate and engage in the theatre or operational environment?
  • What happened during a given scenario time?

Beyond their multifaceted forms and capabilities, EW systems boast high intelligence. With the increased use of adaptive programming, these systems continue to grow smarter. In response to observed effects on the battlefield, they will alter operation via radiated waveforms, techniques, or timing. Waveforms, in particular, change nearly instantaneously. As their responses become more intelligent, it becomes more critical to gauge performance thoroughly to predict the system’s response.

Facing a Complex Future

By recording, you also may capture other systems lurking in the spectrum. In today’s spectrum environment, you need to know that your systems will remain effective when faced by unexpected signal events in dense signal environments. Within the operating radar environment, the range of complexities may include ground clutter, sea clutter, jamming, interference, wireless communication signals, and other forms of EM noise. It may also include multiple targets – many of which utilize materials and technologies that present a reduced radar cross-section. By recording the EMSO environment during testing, you can see what signals are present and whether they have any impact.

With the increasing complexity of the EM battlefield, accurately validating system under test (SUT) stimulus and output data to ensure correct operation is critical. This task becomes more critical as the systems themselves evolve quickly, incorporating new DSP techniques, architectures, materials, and approaches. These systems increasingly operate at higher frequencies as well and demand wider bandwidths. Such complexity makes testing much more difficult. By adding radar recording capability, it is possible to capture and record signals of interest continuously through a test threat scenario in order to truly validate proper operation.

For modern missions, timelines are short and the work increases along with complexity. You need tools that verify if all signals in the test scenario were acquired correctly, if the SUT responded correctly to the threat scenario, and if the correct signals were generated at the right time. The EMSO environment will only grow denser and more crowded. Without being able to predict everything in that environment, knowing how your EW or radar system will perform in the theatre or during an engagement becomes a critical step toward prevailing in that environment.

Keysight offers a variety of solutions to support radar recording and EW and radar test and analysis. The Z2099B Radar Recorder (KRR) is a fully integrated wideband multi-channel system designed for recording and analysis of pulsed signals. In addition, standard hardware and software make the Keysight UXR oscilloscope and PathWave 89600C Vector Signal Analysis Software (VSA) software a commercially off the shelf (COTS) solution for analysing multichannel EW signals.