The Observer: Modal Analysis for Any Structure Type!

Observer Powers Your Entire FDD Operational Modal Analysis Workflow

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The latest Observer features are a game-changing analysis toolkit for civil engineers and researchers working with Operational Modal Analysis (OMA). Digitex Systems designed it for effortless non-destructive evaluation and comprehensive decision-making support for Structural Health Monitoring.

This release now fully supports automated FDD Operational Modal Analysis Methods such as Frequency Domain Decomposition (FDD), Enhanced FDD (EFDD), and Frequency-Spatial Domain Decomposition (FSDD).

Whether you're monitoring bridges, buildings, skyscrapers or rotating machinery, Observer simplifies vibration-driven diagnostics into a unified and intuitive experience!

Let’s see how Observer’s FDD OMA methods work!

The Observer’s FDD Group

Digitex Systems is a Structural Health Monitoring company with only one thing in focus – structural efficiency and people’s safety! The development of its high-quality MEMS accelerometers, digital inclinometers or third-party sensor digitizers was just the first step toward the company’s priority. However, the Observer post-processing software was the last part of this journey and that’s why it had to be the most exciting one.

Currently, the Observer supports a comprehensive Operational Modal Analysis FDD toolkit consisting of FDD, EFDD, and FSDD methods. Each one of them is carefully developed and automated for the needs of every type of civil engineering expert.

The FDD OMA Methods – From the Eye of the Observer

After conducting the non-destructive testing measurements, the Observer enables you to import/create your structural geometry and do a pre-OMA configuration.

Once you do this, you’re ready to proceed to the FDD analysis and report features.

All you have to do is “Initialize the Operational Modal Analysis Parameters and Geometry” and click “Apply Changes”. Then, go to “Model” at the top bar and click the “Analysis” button underneath. This way, you’ll be able to choose your Operational Modal Analysis method to evaluate your conducted SHM measurements.

Frequency Domain Decomposition (FDD)

Once you choose the Frequency Domain Decomposition Method (FDD), a Singular Value Decomposition Diagram (SVD) will be displayed to you. In this case, the Observer will choose the peak values through its peak-picking algorithm.

All you’re left with is to press “Calculate” to see the 3D Mode Shapes of your structure and the identified frequencies.

Enhanced FDD (EFDD)

Another OMA method available with the Observer is the Enhanced FDD (EFDD). The process is basically the same with the addition of calculated damping ratios and more modal functions:

  • SDOF Bell Function vs Frequency: Single-Degree-of-Freedom (SDOF) Bell Function for easy identification of the dominant mode around your resonance peak in the frequency spectrum.
  • Auto-Correlation vs Time: Crucial for estimating the damping rations through the mode’s self-correlation over time after its transformation from a frequency to a time domain.
  • Singular Value vs Frequency: This feature enables you to identify the dominant modes and modal frequencies displayed as singular values.
  • Fitted Exponential Display: Through the standard assumption of decaying of the sinusoidal response, the Observer will automatically display you the free-decay curve and calculate the damping ratios of the particular mode.

Frequency-Spatial Domain Decomposition (FSDD)

The Frequency-Spatial Domain Decomposition (FSDD) is the last of the Observer’s FDD OMA methods group. By following the same steps, our software will take you again to the SVD Diagram and enable you the peak-picking method.

Once you identify and choose your peak values, the Observer will display all the additional modal functions and the 3D mode shape of your structure.

Conclusion

Observer brings the full power of FDD, EFDD, and FSDD into one seamless platform — making advanced Operational Modal Analysis faster, smarter, and more accessible.

From non-destructive testing to long-term Structural Health Monitoring, Observer equips you with precise results, clear visuals, and automated workflows designed for easily assessing structural integrity.

Whether you're part of a vibration monitoring company, a research team, or managing infrastructure health, it's time to modernize your diagnostics with Observer.