How the Triton Quality Factor Helps You Grade Your Data

Built into the firmware of Second Wind’s Triton is a powerful tool that helps you understand your wind data more quickly; allows you to view it more flexibly; and improves the credibility of the data with analysts and independent engineers. Called the Quality Factor, this powerful set of algorithms tags each wind measurement so it can be interpreted and understood both within the SkyServe wind data portal environment and by later analysts. What makes the Quality Factor so powerful, and how can you use it to save time and money?

To understand what makes the Quality Factor powerful, it helps to understand how other wind measurement systems deal with sources of uncertainty. Even though anemometry is still the gold standard by which remote sensing systems are judged, anemometer and vane data do have sources of error, ranging from mechanical failure of the sensors to deadband interpretation, icing, tower shadow, and more. Two anemometers mounted at the same location will not always agree with each other. Remote sensing systems also have known sources of uncertainty, mostly involving the interference of environmental factors and ambient conditions.
To lessen the impact of these discrepancies on a wind resource report, analysts use various methods of filtering or scrubbing the data. With the exception of Triton, no wind measurement system on the market has an algorithmic method of measuring data quality as it relates to the known sources of uncertainty. Anemometry data is analyzed by well-established consultants, using programs and methods that vary depending upon who is doing the analysis. Many sodars and lidars in the market have published quality standards that relate to data recovery, but. these standards only serve as marketing claims. Data recovery statistics are also cited in individual wind measurement reports. But these only answer the question "How much is in the bucket?" They do not qualify the data or provide any method for judging its validity.
Triton's Quality Factor was developed to give everyone from wind developers through investors a way to measure the wind data against the known sources of bias. Data recovery statistics tell you how much data you've gathered. The Quality Factor tells you something about the confidence you should assign to the data. In other words, "What is in the bucket?"
Looking Under The Hood
Triton's Quality Factor operates at the firmware level. For each chirp the Triton sends out, it hears an echo. Each echo is analyzed for quality, primarily signal-to-noise ratio (SNR, which compares the environmental noise to the strength of the echo). Based upon the average SNR of all the chirps sent out during a ten-minute interval, Triton tags each ten-minute average with a Quality Factor number.
Triton sends its ten-minute averages to SkyServe so that you can see your wind data in near-real-time. Each ten-minute average is tagged with the Quality Factor number, and you use SkyServe to filter out data that you don't want to see. It's important to note that neither Triton nor SkyServe use the Quality Factor to change or discard any data. You simply choose what to display or hide based upon your preference. For example, if you set the Quality Factor to 90% in SkyServe, you will see only the data tagged with a Quality Factor number above 90%. It's like only allowing the "A" students to participate in a classroom survey.
How You Can Use Quality Factor To Get Better Returns
Looking at wind data can be confusing. SkyServe's graphical reporting tools already make it easier by displaying Triton data in a similar format to anemometry data. Choosing a Quality Factor threshold allows you to understand how much data you have that is good for a certain purpose. This allows you to make quick judgements about whether a measurement campaign needs to be extended or can be terminated early.
Research has shown that a Quality Factor of 90% is the best-practice standard for wind resource assessment. [For more on this research, and on the business case for the Quality Factor, click to download our free white paper.] By viewing the data with Quality Factor set to 90%, you can quickly see if you have enough data for the wind resource assessment study.
The Triton and SkyServe do not discard any of your wind data. Some analysts ask for all of the raw data so that they can do their own processing and filtering. In these cases, simply set the Quality Factor threshold to zero before exporting.

The same data set, filtered with a high Quality Factor setting of 90% (top, considered acceptable for a wind resource assessment report) and an ultra-high Quality Factor setting of 95% (bottom).
Improved Confidence Reduces Uncertainty
The Quality Factor improves confidence in the Triton data while saving you time and effort. A growing body of wind resource experts -- including independent engineers, consulting meteorologists, wind data analysts, and wind resource assessment service firms -- are experienced in the application of Triton's Quality Factor.
One of the key attributes of sodar and lidar systems is their ability to reduce project uncertainty by measuring the wind across a turbine's rotor sweep. Triton's Quality Factor further reduces uncertainty by qualifying each measurement, providing not only the raw data but also a standard metric for data quality. The Quality Factor is flexible -- providing the analyst with the freedom to choose which data are being viewed -- but the building blocks of the Quality Factor are fixed. Neither the SNR nor the Quality Factor calculations are customer-configurable. This is why all the leading independent engineering firms involved in wind project financing understand and use the Quality Factor as part of their energy projection calculations.