GHRS Instrument Science Report 053 "Using SPYBALs to Improve Pipeline Wavelength Calibrations for the First-Order Gratings of the GHRS" David R. Soderblom, Lisa E. Sherbert and Stephen J. Hulbert Abstract excerpted from the text: GHRS ISR-052 showed that wavelengths produced by PODPS can be significantly in error compared to the solution that would re- sult from obtaining a WAVECAL in conjunction with a science ex- posure. This report illustrates how the information contained in Spectrum Y Balance (SPYBAL) exposure, which is routinely obtained before many GHRS exposures, can be used to correct the default wavelengths so that they are nearly as good as if a WAVECAL had been specified. This procedure can also be used with archival data.
