travel time maps


DATA DESCRIPTION

1. NOAA7973
Dopplergrams:
lat07.5Nlon045.0.fits 
- original MDI level 2 tracked

lat07.5Nlon045.0_start.fits
- 512 min datacube extracted from above, "_start" simply indicates that the
first image corresponds to the first image in the original, thus giving the
time. 
only these in the end).

tt_lat07.5Nlon045.0_LP_r1.51815.fits
- mean travel time for the 512 min doppler. LP - means Low Pass filter
applied during the preprocessing, r1 - resolution used (Mm per pixel)


inv_tt_lat07.5Nlon045.0_LP_r1.51815.fits
- soundpeed inversion delta c/c...inv_(mean travel time filename)...

The rest of the regions are similar...
2. NOAA8038
lat22.5Nlon142.5.fits

3. NOAA9056
lat15.0Slon180.0.fits


4. NOAA9138
lat30.0Slon120.0.fits


5. NOAA9142
lat15.0Nlon045.0.fits

6. NOAA9779
lat30.0Nlon270.0.fits


DETAILS OF ANALYSIS

Low Pass filter 5.2mHz with FWHM 0.2 
travel times were obtained using center to annulus geometry, with annulus
thickness equal to 3 data pixels, i.e. 3*1.51815

r1 is the spatial resolution of the MDI data, i.e. just the value of .125
degrees per pixel translated into MM per pixel.

List of central skip-distances and corresponding phase-speed filter
parameters used

skip-distance  phasespeed flt v0   phasespeed flt dv0
5.83            14.21                 2.63  
7.29            15.40                 2.63  
11.664          17.49                 3.33  
16.038          25.82                 3.86  
20.412          30.46                 3.86  
24.786          35.46                 5.25  
29.16           39.71                 3.05  
33.66           43.29                 3.15  
37.91           43.29                 3.15  
42.28           47.67                 3.57  
46.66           57.16                 3.78  
51.01           57.16                 3.78  


CONTINUUM & MAGNETOGRAMS

SOHO_WLremap_NOAA####.fits - continuum image
SOHO_MGremap_NOAA####.fits - magnetogram