Delay quantization and bandwidth decorrelation ($V/V_0\propto \mathrm{sinc}(\pi \Delta \nu \delta \tau )$)

A residual delay $\delta \tau$ in a rectangular band of width $\Delta \nu$ attenuates the correlated amplitude by $\mathrm{sinc}(\pi \Delta \nu \delta \tau )$. Coarse delay quantization must keep this factor near one; the relevant path scale is $c/\Delta \nu$. Separately, an untracked carrier phase has error $2\pi \delta \ell /\lambda$. Fine phase rotation can remove that central-frequency phase while leaving the band-dependent decorrelation, so delay-step specifications must state both bandwidth and compensation architecture.