The measurement of the frequencies of the intermediate- and high-degree p-mode oscillations is one of the most critical tasks faing the SOI. One of the challenges in making such accurate measurements is the determination of the spherical harmonic degree above which individual modes cannot easily be identified and above which only the p-mode ``ridges'' are observed. Different insturments using different spectral lines and having different spatial and temporal resolutions have obtained somewhat discordant results on the degree at which the individual modes can no longer be observed. We propose to study this problem by examining the model which is used for fitting frequencies to the power spectral peaks in the first place and also by examining the changes in the fitted frequencies which occur as the time series of low-telemetry rate data is increased in length. We also propose to compare the frequencies obtained from the SOI low-rate observations with hose obtained from other simulataneous obserevational programs such as the GONG and the Mt. Wilson-Crimean Network.
A second challenge to the measurement of accurate high-degree p-mode frequenies is the implementation of a frequency correction scheme in which the well-determined modal frequencies are regressed against the observed high-l p-mode ``ridge'' frequencies. We propose here to implement the latest refinements that we have been developing in the analysis of the mt. Wilson high-l observations. In particular, we will implement a correction scheme which takes into account the differing sizes of the errors of the different portions of the l-nu plane and which uses refined fitting algorithms to mimize the effects of systematic variationss in the frequency corrections which have been present in past frequency correction schemes. We will continue to test these new frequency correction algorithms using the combined Mt. Wilson-CrAO two-station network observations which we expect to begin reducing shortly. We will also apply these new algorithms to the correction of the SOI high-degree ``ridge'' frequencies in order to obtain the most accurate frequencies possible.
No additional text was submitted for this proposal.