Spectra

PEC has developed Spectra, a software package for consistent, expedient, and collaborative analysis of Photonic Doppler Velocimetry (PDV) signals. Spectra exists in two forms: the Library provides a toolbox of Python modules, and the Application is a user-friendly desktop application. Both the Spectra Library and Application can be used for exploring, modifying, and analyzing signals. These software tools are designed to be complementary. They were specifically developed for high-throughput automated analysis and are capable of extracting useful data from waveforms with low signal-to-noise ratios.

The Spectra Library is a toolbox of signal processing methods, pipelines, and data formats. The Library is designed for developers comfortable working with Python code. Included in the Library package are: Short-Time Auto-Regression (STAR), a powerful transform capable of high resolution in both time and frequency domains; Variable Baseline Subtraction (VBS), a dynamic method for removing unwanted baseline components from heterodyne PDV probe signals; and Auto-Adaptive Filtering (AAF), a fully automated algorithm for applying progressively narrower time-varying bandpass filters to remove spurious signal elements. The Library is entirely customizable and extensible with support for new or custom filters, transforms, and other processing techniques. It has built-in support for units and custom plotting via common open-source packages.

The Spectra Application is a desktop application for analysis of heterodyne and homodyne PDV signals. Built on top of the Spectra Library, it is easy to use and computationally efficient. Spectra tracks the processing history for each signal to allow analysts to easily share with collaborators and to aid in process improvement. Equipped with batch functionality, the software can analyze any number of input signals with a range of processing sequences for large-volume analysis and parametric uncertainty-quantification. The Application also provides monitoring capability to automatically process waveform files as they are generated by an oscilloscope. The Application is compatible with Windows 7 and later, and can be used on workstations or directly on oscilloscopes. No commercial software is required to run the Application.

Lead Developer: Alex Lakocy, alakocy@protection-consultants.com

Lead Experimentalist: Eddie O’Hare, eohare@protection-consultants.com