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Ring Diagram Development Plan & Status

Team Coordinator: Rick Bogart

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  1. In the matter of infrastructure, the current modules for tracking and power spectral calculation need some fixing and checking, extension to accept a wider class of "conforming" data sets as input, and improved documentation; the module for determining the first-order frequency differences needs to be installed in the SOI pipeline collection. It would be useful to develop a convenient graphical representation for the flow-field maps with appropriate error representations.

  2. We have agreed to analyze artificial data and compare the results with the Ring approach. Frank Hill is currently preparing power spectra with known velocity fields and no noise. We will perform a "forward" analysis: the expected frequency shifts of selected modes will be compared with results from the two fitting approaches.

  3. We should analyze as long a stretch of continuous South Pole data as practicable, on the order of a week, in order to verify the ability of the analysis modules to handle the scale. By independently analyzing subsets of the data, we could learn more about noise and resolution.

  4. We should analyze some Doppler data from Mt. Wilson to learn about the problems and features specific to Doppler vs. Photo data. In particular, the tracking code needs to be freed from image registration. Ed Rhodes and Yong Xue are currently implementing Frank's code; they should be initiated into the workings of the SOI pipeline and help run the Mt Wilson data through it.

  5. If at all possible, we should try to analyze two independent data sets covering the same time and area, to see whether we are really seeing solar signal or systematic instrumental effects. In addition to HLH, South Pole, and Mt Wilson data, we should at least reinvestigate the possibility of looking at TON data.

  6. We need to develop an inversion module, both to be able to present real scientific results, to determine the appropriate spacings in k, and to learn how best to organize the data from the ring fits. We should develop both asymptotics for quick looks (data quality estimation, perhaps) and a real inversion pipe.

  7. The official "Ring" Analysis plan needs to be revisited and updated. We also need to think about higher-order term analysis (sound-speed variations) in the azimuthal Fourier expansion.

A mini-workshop at Stanford is being planned the week of May 22-26. Probable attendees are Deborah Haber, Frank Hill, Ed Rhodes, and Yong Xue.

This page last reviewed and revised 4 May 1995

Please address comments and questions to the Team Coordinator

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