OBSERVATIONS OF INTERMEDIATE DEGREE SOLAR OSCILLATIONS - 1989 APRIL-JUNE

We present frequencies, splittings, and line widths from 85 days of fu ll disk Doppler observations of solar p-modes taken between 1989 April 4 and June 30. We include all modes within the frequency range 2200 m uHz < v < 3500 muHz and with spherical harmonic degrees l > 10 such th at v/L greater-than-or-equal-to 45 muHz, where L = [l(l + 1)]1/2. We d escribe our analysis systems in moderate detail and give evidence indi cating that they are working correctly. Comparison of our mode paramet ers with published Big Bear Solar Observatory (BBSO) results yields go od agreement in general and is thus a confirmation of their work using an independent instrument and set of analysis routines. Small differe nces between the two experiments are consistent with known short-term characteristics of the Sun and the inherent accuracy of the measuremen ts in general. We explain average differences in p-mode frequencies me asured by the two experiments in 1989 spring-summer as a result of dif ferences in the exact periods of data collection during a time of rapi dly changing solar activity. The scatter in these frequency difference s, within narrow ranges of frequency and degree, yields standard devia tions confirming those estimated by the BBSO group from their fitting methods alone. We believe that an almost-equal-to 10% difference in li ne widths between our results and those from BBSO represents the curre nt precision limit of line width measurements due to systematic uncert ainties in calculating spatial crosstalk. We present even splitting co efficients from 1989 and show that their magnitudes are enhanced from 1988 BBSO even splitting coefficients, presumably due to increased sol ar activity. Our odd splitting coefficients for p-modes with v/L great er-than-or-equal-to 45 muHz match, within calculated uncertainties, th ose published by BBSO for their 1986 data, indicating that odd splitti ng coefficients do not vary appreciably with solar activity. We show t hat our a, splitting coefficients for p-modes with v/L < 45 muHz suffe r from a significant systematic error, but we are unable to identify t he cause of this error. We present evidence that a detector distortion or alignment problem, not a problem with the power spectra analysis, is the most likely explanation of this a, anomaly.