The CCD/Transit Instrument (CTI) is a 1.8 m, f/2.2 meridian-pointing telescope located on Kitt Peak. It has no moving parts, but utilizes two RCA charge-coupled devices (CCDs) aligned with columns in the east-west direction and operated in the “time-delay and integrate” (TDI) mode at the apparent sidereal rate to form an image of the sky as it transits (McGraw et al. 1986). The strip is 8.25 arcminutes wide north-south with length determined by the length of the night. Thus, each night the CTI surveys about 15 square degrees of the sky, or about 45 square degrees per year, to a nightly limiting magnitude of mv ≥ 20. One of the two CCDs in the focal plane always observes through a V filter while the other utilizes one of (U), B, R, or I, depending upon the sky brightness. These data are searched to find every detectable object and photometric parameters are calculated for each. These data become part of a Master List which contains the best estimate for each parameter and a History List which maintains a light curve for every detected object. The vital statistics of the project are listed in Table 1.
Digital readout integrated circuit (DROIC) implementing time delay and integration (TDI) for scanning type infrared focal plane arrays (IRFPAs)