Simulation of resonance scattering helioseismometer signals from spatiallyresolved images: Application to the GOLF instrument on SOHO

A step in the analysis of the data from the GOLF (Global Oscillations at Lo w Frequency) instrument on SOHO (SOlar and Heliospheric Observatory, an ESA /NASA Mission) involves the calculation of the sensitivity of the GOLF sign al to the velocity at each point on the solar surface. A successful model o f this sort will permit the intercomparison of data from the spatially reso lved MDI (Michelson Doppler Imager) instrument to the integrated sunlight G OLF signal. This paper presents a formalism and data adequate for the calcu lation of the required sensitivity functions. An important complication in the treatment of the GOLF data is the need to include both the sodium D-1 a nd D-2 lines. The latter is subject to contamination by telluric absorption and is difficult to observe from groundbased systems. This paper presents some telluric corrected data for the D-2 line. The uniform displacement of the solar surface is an important special case which is observed directly b y GOLF The comparison of the appropriate integral of the sensitivity functi on derived from the ground-based profiles to that derived from GOLF data sh ows that the model can successfully reproduce important properties of the G OLF instrument function. A formalism and some data are presented which allo w the calculation of the sensitivity of the GOLF instrument to magnetic eff ects. At present this approach takes a form in which the full magnetic effe ct is approximated by the magnetic effect on the sodium D-1 line alone.