While it makes sense for a 3-station array to only record data when all three stations are tracking the fringe (and this is why this mode was used with NPOI's 3-station configuration), NPOI 6-station data from the hybrid beam combiner are recorded even if up to three stations are in fringe search mode. ... Use Util|Edit (located in plot selection widget) to place three rectangular boxes around the bad data points and flag them. ... This step further eliminates bad tracking data. ... Data loaded. ...