Abstract: Measuring a single linear function q(?1, ?2, . . . , ?d) of unknown parameters {?1, ?2, . . . , ?d} with a quantum sensor network while using the minimum amount of entanglement includes: providing a plurality of d quantum sensors, wherein each quantum sensor j is configured for measuring ?j; preparing the plurality of quantum sensors in a probe quantum state with a minimum amount of entanglement, such that the amount of entanglement is the smallest amount of entanglement that gives the same optimal measurement of the linear function q(?1, ?2, . . . , ?d) as if the amount of entanglement was not restricted; exposing the plurality of quantum sensors to the set of unknown parameters; measuring the plurality of quantum sensors; and calculating the single linear function q(?1, ?2, . . . , ?d) from the measurements of the plurality of quantum sensors with robust phase estimation.