  A locating-dominating set is a subset of vertices representing "detectors" in
a graph G; each detector monitors its closed neighborhood and can distinguish
its own location from its neighbors, and given all sensor input, the system can
locate an "intruder" anywhere in the graph. We explore a fault-tolerant variant
of locating-dominating sets, error-correcting locating-dominating (ERR:LD)
sets, which can tolerate an incorrect signal from a single detector. In
particular, we characterize error-correcting locating-dominating sets, and
derive its existence criteria. We also prove that the problem of determining
the minimum cardinality of ERR:LD set in arbitrary graphs is NP-complete.
Additionally, we establish lower and upper bounds for the minimum density of
ERR:LD sets in infinite grids and cubic graphs, and prove the lower bound for
cubic graphs is sharp.
