# Calculation for new complex magnitude

Complex and pulse compressed complex acoustic data are represented by complex numbers. On echograms, the sample dB values represent the magnitude of the complex number. Some Echoview complex data calculations are handled through the dB values of samples and in a manner similar to the equivalent single frequency, power, Sv or TS data. When a new sample value is required, it is assumed that the phase is unchanged and the new complex magnitude of the sample is calculated as:

where:

ComplexMagnitudeNew is the new complex magnitude value for the new sample.

ComplexMagnitudeOld is the original complex magnitude value for the original sample.

dBValueNew is the new sample dB value as evaluated by Echoview. The evaluation could be a new sample value calculation from one of these operators:

- Attenuated signal removal
- Background noise removal
- Impulse noise removal
- Transient noise smple removal
- Transient noise ping removal
dBValueOld is the original sample dB value.