For Doppler spectra that span a large fraction of the Nyquist velocity range, there may not be enough spectral points to accurately represent the true noise level. For these broad Doppler spectra, the calculated noise may overestimate the true noise. The goal is to replace the elevated noise values with a good estimate of the noise. Typically, ALRC is a constant for a particular installation. The equivalent reflectivity factor can be expressed in log units by and has units of dBZe.
All calculations are in reference to liquid water equivalent reflectivity factor.
Coherent integration is a digital filtering process used by profilers. One side effect of using coherent integration is the decreased power return at frequencies different than zero Doppler shift. 2 v Nyquist velocities. Define Doppler velocity such that downward motion is negative. The Doppler velocity recorded by the profiler is defined as positive motion toward the radar.