         than any interval, within the confinement window, over which
               the specified occultation condition is met. In other words,
               'step' must be shorter than the shortest occultation event
               the user wishes to detect; 'step' must also be shorter than
               the shortest time interval between two occultation events that
               occur within the confinement window (see below). However,
               'step' must not be *too* short, or the search will t