Calibration of the Rossi X-ray Timing Explorer Proportional Counter   Array
  We present the calibration and background model for the Proportional Counter Array (PCA) aboard the Rossi X-ray Timing Explorer (RXTE). The energy calibration is systematics limited below 10 keV with deviations from a power-law fit to the Crab nebula plus pulsar less than 1%. Unmodelled variations in the instrument background amount to less than 2% of the observed background below 10 keV and less than 1% between 10 and 20 keV. Individual photon arrival times are accurate to 4.4 micro-seconds at all times during the mission and to 2.5 micro-seconds after 29 April 1997. The peak pointing direction of the five collimators is known to a precision of a few arc-seconds 
K. Jahoda (1), C. B. Markwardt (1,2), Y. Radeva (2,3), A. Rots (4), M.   J. Stark (5), J. H. Swank (1), T. E. Strohmayer (1)...