Noise Correction
turns noise correction on or off by checking or clearing the Noise Correction checkbox.
This parameter is available with Power Spectrum, Adjacent Channel Power and Spectral Emissions Mask measurements.
Noise correction or "noise floor extension" (NFE) is an algorithm that improves measurement accuracy by using information about the instrument's noise floor. The noise correction algorithm automatically disconnects the analyzer's front-end to measure the internal noise floor, reconnects the front end to take another measurement, and then displays the corrected result on the analyzer screen. The VSA status bar will display "Measuring noise correction" when noise correction is turned on and a noise correction measurement is in progress.
Decrease the video bandwidth relative to the resolution bandwidth in order to increase the amount of noise correction. If the video bandwidth is set to Auto, the video bandwidth will automatically be set to a value that is significantly smaller than the resolution bandwidth.
Noise Correction and Measurement Speed
The noise correction algorithm requires two measurements and doubles the measurement time the first time a measurement is run with noise correction turned on. Measured Noise Correction Spectrum results are cached and reused in subsequent measurements as long as measurement parameters haven't changed. Noise correction will automatically run again if the setup has changed in a way that might affect the instrument noise level and there isn't a cached noise correction for the changed setup.
If you need to increase measurement speed, consider disabling noise correction in the following situations:
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when the signals of interest are sufficiently above the noise floor
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when your signal environment is relatively free of noise
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when the noise isn’t significant enough to affect your measurements
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when you can live with the level of degradation that will be present in the results
See Also
