FOS Internal/External Wavelength Offsets


W. P. Blair, G. A. Kriss, and A. F. Davidsen
The Johns Hopkins University


Instrument Science Report CAL/FOS-056
December 1988



Abstract

We investigate the wavelength offsets observed between the internal
calibration lamps with respect to an external calibration lamp using
data. obtained with the FOS during the March 1988 and August 1988
calibration runs at Lockheed. The offsets are quite different than
those observed in earlier calibration data and in general are
considerably smaller. The improvement is most likely due to better
alignment of the Digicons that was achieved using a new procedure just
prior to the March calibration and was used again in August for the
final alignment.