sisThickMaps package

	author: bruce sears
	released: 3-19-97

	This package is used for determining the absolute thickness
	of a sis detector given the number of the sis detector and a
	point (x, y) on the detector.

	IMPORTANT: This package relies on the package idlUtilities_bs being
	installed on your system (and in your IDLPATH).

version 1.02:
	fixed factor of 2 problem in interferometer dT maps

version 1.01:
	added missing data for P1000 detector in absThickAt00.db file

version 1.00:

	Calls:
		get_sis_thickness, detNum, x, y, thickness, extrapCount

		in:
			detNum = sis detector number (integer)
				e.g., use detNum = 1000 for P1000,
				use detNum = 0 for ACE000, etc.
			x, y = point on the detector (float, float)

		out:
			thickness = thickness at (x, y) in microns (float)
			extrapCount = the value of thickness at (x, y)
				is interpolated between the 4 nodes
				at the corners of 5 mm x 5 mm pixels.
				The nodes correspond to the points which
				were measured by the interferometer maps
				of the sis detectors.  At the edges of the
				detector, the thickness has been extrapolated
				to the nodes outside of the actual measurments.
				extrapCount will usually return as 0, but near
				the edges of the detector may be from 1 to 3.
				if extrapCount = 4, the point you are looking
				at is probably not physically on the detector
				even though get_sis_thickness may return a
				thickness value using 4 extrapolated nodes.
				(integer)