High Quality Content by WIKIPEDIA articles! The InterPlanetary Network (IPN) is a group of spacecraft equipped with gamma ray burst (GRB) detectors. By timing the arrival of a burst at several spacecraft, its precise location can be found. The farther apart the detectors, or the greater the timing precision of each detector, the more precise the GRB location. Typical spacecraft baselines of about one AU (astronomical unit) and time resolutions of tens of milliseconds can place a burst within an error box of several arcminutes, for followup with more powerful instruments.