EXFO FTB -5240S/5240BP Optical Spectrum Analyzer for FTB 500 (NS-1434) - Manual (Page 309)

Managing Results
Optical Spectrum Analyzer 301
Managing WDM Test Results
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Signal power calculation: indicates which calculation method to
apply for signal power value.
Integrated signal power: The integrated signal power represents
the sum of the power values included between the channel limits
of this channel, minus the estimated noise contribution between
the same boundaries. In some cases, for instance CATV signals,
signals with high-frequency modulation, or signals with an
inherent line width similar or larger than the OSA's resolution
bandwidth, this calculation becomes a better estimation of the
true signal power.
Peak signal power: The peak signal power represents the
maximum power value inside the channel, but it differs a little
from the peak measurement on the spectrum due to the fact that
the estimated noise is subtracted to get the peak signal power.
Total channel power: The total channel power represents the sum
of the power values included inside the channel width (including
noise).
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Noise for OSNR: indicates which calculation method to use for
OSNR value.
Fixed range IEC based (IEC): The IEC method uses the
interpolation of noise measured on both sides of the signal to
estimate the noise level. The position at which the noise is
estimated from the center wavelength is given by the OSNR
distance.
In-Band (InB): The In-Band method uses a series of scans having
different polarization states to calculate the noise level in band.
In-Band narrow filter (InB nf): The In-Band narrow filter method
uses the In-Band method with additional processing to provide an
accurate OSNR value for the narrow carved noise. This is because
with narrow filters, the noise level under the peak is not uniform
and the OSNR value depends on the processing width selected.