Methods for correcting systematic errors in the measured position of
deposited features of a nucleic acid array on a substrate. Systematic
errors are modeled by an algorithmic model based on measuring the
positions (and possibly other properties) of a subset of the features,
and a model is constructed for predicting deviations in feature position
from an ideal grid. Deviations arising in the deposition process, the
scanning process, or both may be corrected.