Dynamic-Scanning Spectral Analyzer

SAJ Specifications

   See: Dynamic-Scanning Spectral Analyzer)

SAJ is an easy way to express your results -- be scientifically precise, without needing to write a whole paragraph on signal-processing -- just write "as per the SAJ-1 specification."

Your results from the program are automatically expressed in SAJ-1. This ensures uniformity between different researchers in different fields.

Readouts

SAJ-1 provides a statistical summary of what is contained inside a region on a spectrogram. Rather than writing down the amplitude of every pixel on the spectrogram, it is possible to summarize the distribution of energy using a few numbers. The most basic ones are:

Conservative approach to Accuracy

SAJ-1 expresses +/- uncertainties with a cautionary approach. A +/- error is given to all the Fundamental Center and Bulk Spread numbers. The algorithm used is fairly conservative in its statements of accuracy, to avoid an overly optimistic perception of that accuracy. In practice, the "center" accuracy tends to be better than what the +/- numbers would warn.

However, it is very important to pay attention to the Enclosure Quality (Measurement Quality) numbers. If the quality is below 3dB or so, that indicates a rather poor positioning of the boxes around the event, and so the results might be corrupted. A quality of 12dB or higher indicates an excellent capture of the spectral peaks.

It is the responsibility of the user to position the boxes on the spectrogram so they properly surround the event, including an extra margin on all four sides.


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