  We present a method to mitigate the effects of fiber assignment
incompleteness in two-point power spectrum and correlation function
measurements from galaxy spectroscopic surveys, by truncating small angular
scales from estimators. We derive the corresponding modified correlation
function and power spectrum windows to account for the small angular scale
truncation in the theory prediction. We validate this approach on simulations
reproducing the Dark Energy Spectroscopic Instrument (DESI) Data Release 1
(DR1) with and without fiber assignment. We show that we recover unbiased
cosmological constraints using small angular scale truncated estimators from
simulations with fiber assignment incompleteness, with respect to standard
estimators from complete simulations. Additionally, we present an approach to
remove the sensitivity of the fits to high $k$ modes in the theoretical power
spectrum, by applying a transformation to the data vector and window matrix. We
find that our method efficiently mitigates the effect of fiber assignment
incompleteness in two-point correlation function and power spectrum
measurements, at low computational cost and with little statistical loss.
