... Nearly all FOS observations included an onboard target acquisition that used instrument observing modes to locate the science target in the desired aperture. ... No FOS acquisition exposure (e.g., an ACQ/BINARY exposure or a single scan-pattern of an ACQ/PEAK) could be interrupted by Earth occultation. ... Binary search acquisition mode is indicated by a raw data header file (. d0h ) OPMODE value of ACQ/BIN. ... In the following we use the term FOS ACQ Imaging to refer to all of these imaging modes....