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Time-Distance Pipeline for the Upper 30Mm Convection Zone Status 11/5/2007

Time-Distance Pipeline for the Upper 30Mm Convection Zone

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Time-Distance Pipeline for the Upper 30Mm Convection Zone. Status 11/5/2007. Code: fastrack R.Bogart, T.Duvall J.Zhao Status: needs improvements (remapping issues) Additional funding: none. Code: cross-covariance T.Duvall J.Zhao Status: needs improvements Additional funding: none. - PowerPoint PPT Presentation

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Page 1: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Time-Distance Pipeline for the Upper 30Mm

Convection ZoneStatus 11/5/2007

Page 2: Time-Distance Pipeline for the Upper 30Mm Convection Zone

DopplerVelocity

Tracked TilesOf Dopplergrams

Filtergrams Time-distanceCross-covariance

functionWave travel times

Deep-focus v and cs

maps (0-200Mm)

High-resolution v and cs

maps (0-30Mm)

Carrington synoptic v and cs

maps (0-30Mm)

Full-disk velocity, v(r,Θ,Φ),And sound speed, cs(r,Θ,Φ),

Maps (0-30Mm)

Time-Distance Helioseismology

Code: fastrackR.Bogart,T.DuvallJ.Zhao

Status: needs improvements (remapping issues)

Additional funding: none

Code: cross-covarianceT.DuvallJ.Zhao

Status: needs improvements

Additional funding: none

Code: travel time fittingT.DuvallJ.ZhaoS.Couvidat

Status: needs improvements

Additional funding: none

Code: sensitivity kernelsA.KosovichevJ.ZhaoA.Birch

Status: needs improvements

Additional funding: Birch: 2 PM

Code: inversionsA.KosovichevJ.Zhao, A.BirchS.CouvidatJ.ToomreB.Hindman

Status: needs improvements

Additional funding: Toomre:5 PM

Code: deep-focus mapsT.DuvallA.KosovichevJ.Zhao

Status: needs substantial development

Additional funding: need new postdoc at Stanford

Page 3: Time-Distance Pipeline for the Upper 30Mm Convection Zone

TaskInput: Output:

Dopplergrams

Active region structures and flows

Synoptic flow maps

Page 4: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status: Cross-Covariance

Code: cross-covarianceT.DuvallJ.Zhao

Status: needs improvements

Additional funding: none

Task: Do filtering and compute cross-covariance

Status:• filtering: code ready, comparisons among Tom, Sebastien and myself have achieved excellent results• cross-covariance computation: code ready, comparisons also done, and excellent results achieved• selection of annulus pixels: algorithm has been compared between Tom and me, a Fortran code needs to be developed for the active region cases. Synoptic flow maps will use pre-computed locations.

Summary: Nearly done except one subroutine for on-fly computation of annulus pixels. Module is needed.

Page 5: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status: Travel Time Fitting

Code: travel time fittingT.DuvallJ.ZhaoS.Couvidat

Status: needs improvements

Additional funding: none

Task: Fit cross-covariances to derive acoustic travel times

Status: • As of last Friday, comparisons among Tom, Sebastien and myself are still going on. I am optimistic that excellent results will be achieved. • Codes in Fortran are largely ready. Only some fine-tuning is needed in some parameters. • Fitting code based on Gizon-Birch method was written by Sebastien and ready to be incorporated into main code.

Summary: Nearly done except incorporating Sebastien’s subroutine. Module is needed.

Page 6: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status: Sensitivity Kernels

Code: sensitivity kernelsA.KosovichevJ.ZhaoA.Birch

Status: needs improvements

Additional funding: Birch: 2 PM

Task: Compute sensitivity kernels as input for the inversion code

Status:• Ray-approximation kernels: a few codes exist, some comparisons have been planned to finalize this. • Born-approximation: Birch code ready for use with some opitmization that is being carried out by Konstantin. Also MPI can provide this.

Summary: in a pretty good shape. Should be finished in a couple of months.

Page 7: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status: Inversions

Code: inversionsA.KosovichevJ.Zhao, A.BirchS.CouvidatJ.ToomreB.Hindman

Status: needs improvements

Additional funding: Toomre:5 PM

Task: Develop code to do inversions

Status: • Pipeline work on this part is barely started.• Codes for two different algorithms (LSQR and MCD) exist. Probably both algorithms will be put into pipeline. • Some comparisons between different codes and different algorithms are needed.

Summary: Barely anything has been done. A lot of efforts are needed in this. An estimate of 6 months(?) is required for this part of work.

Page 8: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Additional Issues• Poor or no noise estimations in both time-distance measurements and inversions. This needs a great deal of research efforts to implement it. Not sure whether this part can be accomplished by the time of March 2009.• Sebastien has code for inversions with noise covariance. • All codes are based on MDI observations. Some parameter changes and more testing is needed for HMI observations.• Co-I asks for more support. • Overall, it is very optimistic to deliver all codes before March, 2009

Page 9: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Computer Requirement

• Now we are ambitious in computing 17 different annuli for HMI data

• Computing 17 annuli using 512-minute MDI full-disk data takes approximately1.5 hours on 1 LWS cluster node for 1 of 9 regions selected on solar disk.

• We do not yet know whether we will use HMI full resolution to do this.

• We save fitted travel times and inverted 3D velocity and 1D sound-speed perturbation for approximately 15 depths. Every 8.5 hours, it takes 62MB saving space for MDI resolution.

Page 10: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Time-Distance Pipeline for Far-side Imaging

Status 11/5/2007

Page 11: Time-Distance Pipeline for the Upper 30Mm Convection Zone

TaskInput: Output:

Dopplergrams

Far-side images

Page 12: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status• All codes for computing travel times are ready in Fortran. Some

processing and making of maps after travel times are in IDL. • Each far-side map is combined from one 4-skip map and one 5-

skip map.• Module is needed. • Should be able to share a lot of things with holography far-side

imaging, hence saving a lot of computing and storage resources.

Computer Requirement• One map is made every 12 hours• Using MDI medium-l data, one map needs about 1 hour computing time using one LWS2 cluster node. • Storage space is quite small.

Page 13: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Issues

• No additional support is needed.• Though codes are ready, results are published, maps

are not widely available online and seen by colleagues. Hence, it is useful to broadcast the results so as to receive feedbacks from colleagues.

• Statistical study regarding to how much we can believe in those images, which part of images is more reliable and which part is not reliable.

• Systematic comparison with holography far-side images is probably necessary.

Page 14: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Helioseismic Holography Pipeline

Status 11/5/2007

Page 15: Time-Distance Pipeline for the Upper 30Mm Convection Zone

DopplerVelocity

Tracked TilesOf Dopplergrams

Filtergrams Egression andIngression maps

Wave phase shift maps

Far-side activity index

High-resolution v and cs

maps (0-30Mm)Acoustic Holography

Code: fastrackR.BogartD.BraunC.Lindsay

Status: needs improvements (field-effect corrections)

Additional funding: Braun: 2 PM

Code: egression-ingressionD.BraunC.Lindsay

Status: needs improvements

Additional funding: none

Code: phase shiftsD.Braun C.Lindsay

Status: needs improvements (showglass corrections)

Additional funding: Braun: 3 PM

Code: sensitivity kernelsA. Birch

Status: in development

Additional funding: Birch: 2 PM

Code:holographic inversionsA.Birch

Status: in development

Additional funding: Birch: 6 PMLindsay: 6 PMProgrammer: 0.5 PM

Code: Far-side imagingP.ScherrerC.LindsayD.Braun

Status: needs improvements

Additional funding: Lindsay: 4 PMProgrammer: 0.5PM

Inversions

Page 16: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status (I)

Code: egression-ingressionD.BraunC.Lindsay

Status: needs improvements

Additional funding: none

Code: phase shiftsD.Braun C.Lindsay

Status: needs improvements (showglass corrections)

Additional funding: Braun: 3 PM

Task: Compute egression and ingression functions, and measure acoustic phase shifts by cross-correlating egression and ingression

Status: Codes are essentially existing for MDI-type data, though some improvements are necessary, and some tuning to fit HMI is also required.

Page 17: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status (II)

Code: sensitivity kernelsA. Birch

Status: in development

Additional funding: Birch: 2 PM

Code:holographic inversionsA.Birch

Status: in development

Additional funding: Birch: 6 PMLindsay: 6 PMProgrammer: 0.5 PM

Task: Compute sensitivity kernels, and invert for flow fields based on phase-shift measurements

Status:Still under development. Only very limited experimental coding has been developed.

Page 18: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Status: Far-side Imaging

Code: Far-side imagingP.ScherrerC.LindsayD.Braun

Status: needs improvements

Additional funding: Lindsay: 4 PMProgrammer: 0.5PM

Status:Codes are ready and are already run in MDI pipeline, though retooling to HMI is needed. Researches on corrections, calibrations and near-side limb imaging are carried out, but do not yet promises anything for updating or improving for HMI pipeline.

Page 19: Time-Distance Pipeline for the Upper 30Mm Convection Zone

Issues

• Nearly all codes are needed to be re-adjusted to HMI. • Without additional funding, the codes they provide will

be quite limited in utility and scope:

* use local plane-parallel geometry;

* have limited or no corrections in large-scale artifacts

* no treatment on magnetic surface effect

* far-side images will have little or no calibration.