GPC1 and GPC2: the Pan-STARRS 1.4 gigapixel mosaic focal plane CCD cameras with an on-sky on-CCD tip-tilt image compensation

We will report on the on-sky, on-CCD, tip-tilt image compensation performance of GPC1, the 1.4 gigapixel mosaic focal plane CCD camera for wide field surveys with a 7 square degree field of view. The camera uses 60 Orthogonal Transfer Arrays (OTAs) with a novel 4 phase pixel architecture and the STARGRASP controller for closed loop multi-guide star centroiding and image correction. The Pan-STARRS project is also constructing GPC2, the second 1.4 gigapixel camera using 64 OTAs. GPC2 will include design enhancements over GPC1 including a new generation of OTAs, titanium mosaic focal plane with adjustable three point kinematic mounts, cyro flex wiring and the recent software distributed over 32 controllers. We will discuss the design, cost, schedule, tools developed, shortcomings and future plans for the two largest digital cameras in the world.