Sensitivity of the GOLF signal to combined solar velocity and intensity variations

The GOLF instrument provides a stable and continuous measurement of the int ensity of spatially integrated sunlight in one wing of the sodium D lines. Because the detected radiation results from atomic scattering, the GOLF sig nal can be traced to an atomic reference wavelength. The planned operations were to involve a form of relative photometry through the use of measureme nts on both the blue and red wings of the solar D lines of neutral sodium. However, due to the occasional malfunction of the polarization subsystem a "one wing photometric mode" operational alternative has been selected in or der to ensure achievement of a 100% duty cycle. In this case, the signal ob served consists of two photometric measurements at only one wing of each li ne of the sodium doublet separated by g x 0.43 picometers (pm). The sodium cell system in GOLF combines photons scattered at three different wavelengt hs: one at D-1 and two at D-2. This paper developes a formalism to describe this system in terms of the solar spectral line profiles. A method of conv erting the one wing data to an effective velocity scale is presented. The m ethod is applied to the nearly continuous 804 day sequence received from th e GOLF instrument prior to the loss of telecommunications with SOHO on 24-J une-1998. The resulting time sequence is part of the GOLF archive and can b e made available to investigators. This publication describes some properti es of this time series.