Passage: The initial version of the Intruder was built around the complex and advanced DIANE (Digital Integrated Attack/Navigation Equipment), intended to provide a high degree of bombing accuracy even at night and in poor weather. DIANE consisted of multiple radar systems: the Norden Systems AN/APQ-92 search radar replacing the AN/APQ-88 on YA-6A, and a separate AN/APG-46 for tracking, AN/APN-141 radar altimeter, and AN/APN-122 Doppler navigational radar to provide position updates to the Litton AN/ASN-31 inertial navigation system. An air-data computer and the AN/ASQ-61 ballistics computer integrated the radar information for the bombardier/navigator (BN) in the right-hand seat. TACAN and ADF were also provided for navigational use. When it worked, DIANE was perhaps the most capable nav/attack system of its era, giving the Intruder the ability to fly and fight in even very poor conditions (particularly important over Vietnam and Thailand during the Vietnam War). It suffered numerous teething problems, and it was several years before its reliability was established.

Question: What does BN stand for?
bombardier/navigator