  The position accuracy based on Decawave Ultra-Wideband (UWB) is
affectedmainly by three factors: hardware delays, clock drift, and signal
power. Thisarticle discusses the last two factors. The general approach to
clock drift correc-tion uses the phase-locked loop (PLL) integrator, which we
show is subject tosignal power variations, and therefore, is less suitable for
clock drift correction.The general approach to the estimation of signal power
correction curves re-quires additional measurement equipment. This article
presents a new methodfor obtaining the curve without additional hardware and
clock drift correctionwithout the PLL integrator. Both correction methods were
fused together toimprove two-way ranging (TWR).
