SQLX is a unique seismological data analysis tool useful for both Data Quality Control and Research
The Challenge
The amount of seismological data being collected around the world is growing every day. Consequently, it is increasingly important to be able to:
- Accurately validate the quality of incoming data
- Easily analyze large and complex data sets to find events and signals of interest
- Quickly alert network operators of problems
The Solution
SQLX is an effective and efficient tool that addresses these concerns and more. Requiring minimal configuration, SQLX converts time-domain data into Power Spectral Density (PSD) equivalents in the frequency domain. Using these PSDs, different types of plots are created for analysis and inspection. Available plots include: PSDPDF, spectrograms, seasonal and diurnal spectrograms, and more.
With data converted to the frequency domain, “noise” is readily visualized and easy to interpret. For example, network operators will know if a station is not optimally performing, allowing them to easily identify the exact problem, when it occurs, and what needs to be done to ensure that the data is of the highest quality possible.
Using the baseline feature, a signal of interest in the frequency domain may be imported to identify all PSDs where this signal appears, in other words, a frequency-domain picker. Finding events of interest in a large data-set is simple and straightforward.
SQLX is a robust tool that features many time-domain and frequency-domain analysis techniques developed over the course of 25 years. It is designed to handle, and provide new insights into, ultra-large data-sets (terabytes+).
For all data channels, SQLX provides statistics for:
- The maximum and minimum noise levels across all frequencies
- The nominal noise levels to be expected over all time, per station and per channel
- Proximal human noise sources – motors, trains, vehicles, etc.
- Natural noise sources – earthquakes, ocean waves, glaciers, weather, etc.
- … and how each of these may vary over time
Product Descriptions
- Basic: A graphical-based program providing basic waveform analysis functionality: zooming, scaling, data inspection, overlay, data transformation, filtering, spectra, and more. Every aspect is configurable with configuration retained between executions.
- Standard: Expanding on the Basic product, includes PSDPDF analysis and addition plots by storing all PSDs in a local database for later retrieval. Display of time-domain data by station up to 60 days on a single line. PSD data can also be graphically queried to answer questions such as: When do problems compromising the data occur? What noise levels can I expect to see over all time for a particular station and channel? How often does a particular (type of) signal occur?
- Premium: Further expanding on the Standard product, contains all the new developments since 2012, including but not limited to: many new plot types based on PSD data; frequency bins generalized between 256 kHz and one million seconds, allowing for direct comparison of PSD data between all existing channels; execution efficiencies to work for very large data-sets (terabytes+) and very large numbers of CPU’s (80+), and more.
- A complete list of features available by product can be found here.
- A no-obligation trial subscription can be found here.
- Quarterly and annual subscriptions can be found here.
Use Cases
- Data Quality Control: Identify potential data problems – in order to apply corrections.
- Network Operations: Manage any size network to detect and diagnose problems with stations in near real-time, enabling quick fixes.
- Signal Identification: Convert data to frequency domain to find events of interest quickly and easily across an entire data-set.
- Site Location: Thoroughly test a site location before committing to a permanent installation.
- Site Response Characteristics: Identify how each component of a site contributes to overall noise levels. For example, what is the effect of soil density? Do installation-specific details (e.g., vault vs. above-ground) have an adverse influence on noise levels? Are there long-period variations (e.g., tilt) needing mitigation? etc.
- Station Characteristics: Determine expected noise levels across frequencies over time, and to determine minimum event detection thresholds.
- Dam and Building Monitoring: Monitor potentially damaging strong motion events, and determine harmonic resonances.
- Volcano Monitoring: Monitor daily activity and swarm events, and help determine threat levels.
- Hardware Design and Verification: Test performance of hardware, being built or being purchased, across the frequencies for which it is expected to perform.