Solutions should be IDL ".sav" files with the data-name and a unique indicator such as "first_initial+last_name_filename.sav" For example, my solution for AR9026 would be called "KLeka_IVM_AR9026.sav". The depositing/incoming address is ftp://ftp.cora.nwra.com/incoming/AMBIGUITY_WORKSHOP Please contact me if you have any questions at leka@cora.nwra.com Thanks! -KD Dear Colleague, We are now set for the second attempt at the Ambiguity Resolution Workshop here in Boulder, 26-27 September 2005. It is time now to start preparing for the workshop. Most of you have made travel arrangements by now. If you need further assistance, please contact Louise Beierle (louise@ucar.edu, 303-497-1599). The meeting will be held in the new location of HAO: NCAR Center Green (CG-1), Room 2126. This is a smaller meeting room in the same building that the SPW4 Workshop will be held the preceding week. This building is adjacent to the Residence Inn where many of you will be housed. The new draft of the agenda is attached as a PDF document "Agenda_sept05.pdf". It has not been altered greatly from the Agenda set for the April meeting. We are using this new agenda as a guideline; the schedule will be flexible. Further information regarding the workshop and preparation of ambiguity resolutions follow below. We look forward to seeing you in Boulder at the end of September (and let's hope there is no snow)! Sincerely, Bruce Lites KD Leka Tom Metcalf ============================================================================= CONFIRMED ATTENDEES: Name Affiliation Email Arturo Lopez Ariste THEMIS alopez@themis.iac.es K. S. Balasubramaniam NSO/Sunspot bala@nso.edu Graham Barnes NWRA/CORA graham@cora.nwra.com Allen Gary MSFC Allen.Gary@nasa.gov Manolis Georgoulis APL/JHU manolis.georgoulis@jhuapl.edu Jack Harvey NSO/Tucson jharvey@noao.edu Carl Henney NSO/Tucson chenney@noao.edu Ju Jing BBSO/NJIT jj4@njit.edu K.D. Leka NWRA/CORA leka@cora.nwra.com Yang Liu Stanford quake.stanford.edu Bruce Lites HAO lites@ucar.edu Tom Metcalf NWRA/COR metcalf@cora.nwra.com Nour-Eddine Raouafi NSO/Tucson raouafi@noao.edu Paul Seagraves HAO paul@hao.ucar.edu Meir Semel Obs. Meudon, Paris meir.semel@obspm.fr Steve Tomczyk HAO tomczyk@ucar.edu There are several other people who are likely to be attending (Rees, Martinez Pillet in particular) who are registered to attend the SPW4, but I have not heard if they are also coming to the Ambiguity workshop. ========================================================================= TRIAL DATA SETS: As we agreed before the April Meeting, in order to compare resolution techniques we suggest that people apply their methods to particular selection of data sets. The data sets may be found now at both HAO and CoRA's ftp sites: http://download.hao.ucar.edu/pub/lites/ambiguity simulations/fan_simu_ts56.sav simulations/Barnes_TPD7.sav ASPdata/ASP_b24jun92.sav IVM/IVM_AR9026.sav http://www.cora.nwra.com/AMBIGUITY_WORKSHOP/DATA_FILES fan_simu_ts56.sav Barnes_TPD7.sav ASP_b24jun92.sav IVM_AR9026.sav To provide solutions, please use the anonymous ftp site ftp://ftp.cora.nwra.com/incoming/AMBIGUITY_WORKSHOP put your solution for each test case there with a unique indicator. As an example, use first_initial+last name in the name of the file you are depositing. If you have more than one solution please use '1', '2' consistently in the file name. For example, my solution for AR9026 would be called "KLeka_IVM_AR9026.sav". Please submit solutions by Tuesday 20 September. The data sets are presented as an IDL-structure following the Hawaii data format (outlined below) in an IDL save file (".sav"), please adhere to this format for presenting your solutions. In particular, results must be presented in the observer's frame, just as the original data, and the azimuth b_azim should be limited to the range +/- 180 degrees. IF you have any questions concerning coordinates, please try the IVM_AR9026.sav data set and send a test solution to KD as soon as possible. That data set includes a simple potential sunspot observed away from disk center, and as such can be used as a consistency check. B_AZIM is the ONLY parameter that will be used directly in the comparisons. That is, if you return simply the same structure but an updated b_azim tag, that will be sufficient. We will recompute Bx,By,Bz from your provided b_azim for comparisons in heliographic coordinates. There are two cases (fan_simu_ts56.sav and Barnes_TPD7.sav) for which the answer is known. As such they comprise the higher priority for our comparisons. The second two cases result from observations. Other data were provided from various sources for the April workshop, and while everyone is encouraged to experiment with those, the workshop will focus solely on these four with a higher priority on the model data. Thus if time is an issue, please provide solutions only for the model data. Everyone who is presenting a method or works with vector field data is encouraged to "put their money where their algorithms are", and submit solutions to the trial data sets. THANKS! =================================================================== DATA FORMAT: The following is the "Hawaii" data format: an IDL-save file containing a structure (named or anonymous) that presents the vector field and coordinates with tags: {i_cont,latitude,cmd,b_long,b_trans,b_azim,bx,by,bz,point} where "point" is itself an IDL named structure containing the pointing information: point = {point,lat,cmd,b0,p,radius,pix_size} The following are two-dimensional arrays: i_cont: continuum intensity latitude: solar latitude array for each point in the field, measured northward from the solar equator, in degrees cmd: solar longitude array for each point in the field, measured westward from the central meridian, in degrees b_long: longitudinal field strength, Gauss (averaged over the pixel if the analysis calculates a fill fraction) b_trans: transverse field strength, Gauss (averaged over the pixel if the analysis calculates a fill fraction) b_azim: azimuth angle of the transverse component of the field vector in the plane of the sky, measured counterclockwise from solar north, in degrees, +/- 180 (in ambiguous data it may be +/-90 or 0-180 or similar). In your provided solutions this will be YOUR ANSWER. bx,by,bz: the three components of the field vector in the "local solar frame": bx = field component directed solar West > 0, East < 0, by = field component directed solar North > 0, South < 0, bz = field component normal to the solar surface, outward > 0. These data are part of the structure, but not necessary for the ambiguity resolution, or for the final comparisons. Please do your resolution starting from the b_long, b_trans, and b_azim. The structure "point" contains the following quantities: lat: float, solar latitude of center of the observed field, radians cmd: float, solar longitude of the center of the observed field, radians be careful, the array for longitude in the main structure has the same name and different units!) b0: the ephemeris value for inclination of the solar rotation axis to the plane of the sky, radians p: the ephemeris value for the angle the solar rotation axis with respect to the terrestrial north direction, in radians. This quantity can be set to zero if the solar north direction is along the ordinate (slow axis) of the data arrays radius: solar radius as seen from Earth at the time of the observation, in arcseconds pix_size: two-dimensional array containing pixel dimensions [horizontal,vertical], in arcseconds Additional tags are accepted.