Program Traces Rays With Quadruple Precision

QRAYPKS is a general-purpose FORTRAN optics-analysis computer program that enables the computation of path lengths to an unprecedented level of precision. The impetus for developing QRAYPKS was the need to mathematically model an outer-space laser interferometer to be used in detecting gravitational waves; the interferometer is expected to have a baseline about 5 million kilometers long, and it is necessary to be able to compute the length of the baseline to subpicometer precision. QRAYPKS can also be used to model other large optical systems in their entirety.