2 and the instrument is non-imaging. However, the PCA can be scanned across a target region and the location of a bright source determined to an accuracy of 1-2$\arcmin$ by fitting the collimator response to the observed count-rate.

The low extinction and unobstructed line of sight to the SMC enable accurate measurements of X-ray luminosity and useful observations of the optical counterparts with 1-2m telescopes [see for example @edge2002]. From the X-ray viewpoint, since the distance to the SMC is significantly greater than its ’depth’ all of the objects in the SMC can be considered to lie at an equal distance for the purposes of luminosity calculations.

Observing Strategy
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The [[*RXTE* ]{}]{}Proportional Counter Array (PCA) [@Jahoda96] was used to make regular observations of the SMC to look for new X-ray pulsars and monitor the outbursts of known systems. The instrument consists of 5 co-aligned Proportional Counter Units (PCU), each has a xenon filled detector volume with 3 layers of anode-grids for photon detection plus a lower xenon veto layer for background rejection. Propane-filled veto detectors are positioned above the PCA to attenuate particle background and non-source direction X-rays. Operated in Good Xenon mode, individual photon arrival times are recovered 