------------------------------------------------------------------------
v1_1 Rel. 2 (27-Jul-2003) runs with idlutils v4_10_4 + healpix package

- Updated HEALPix file binary table headers to be strictly FITS
  compatible.  The NAXIS* keywords were out of order, and the SIMPLE
  keyword was present and should not have been.  This caused read
  errors for some FITS readers.  Thanks to Wayne Landsman for pointing
  this out.  Only the last step of the pipeline was rerun (healpix_halpha).

------------------------------------------------------------------------
v1_1 (25-Jan-2003) runs with idlutils v4_9_14 + healpix package

- Apply calibration factor of 0.8 to the VTSS data, with permission of 
  Dennison & Simonetti.

- Add CALIB header card to VTSS files with calibration factor.

- Make FITS astrometric header CD matrix double precision.

- Fix some plot labels in postscript figures.

- Add WHAM HI_VEL mask for pixels thought to have significant emission
  at v > 80 km/s.  This is now bit 7 of the bitmask. 

- Use floatcompress routine on data to improve gzip efficiency.
  Maximum fractional error introduced is 1/4096 in data and 1/256 in
  errors (results in factor of 3 compression). 

- Interpolate over l = +-180 better for healpix maps. 

- Compute airmass correction for SHASSA but do not apply.

- Mask bad WHAM pointings before doing interpolation / median filter
  of WHAM minus {SHASSA,VTSS} residual. 

- Change label of shassa_wing figure from arcsec to arcmin.


------------------------------------------------------------------------
v1_0 (25-Sep-2002) runs with (?) idlutils v4_9_13 (+ other dependencies)

- Apply WHAM zero-point to SHASSA, not just VTSS!

- Change criterion for good postage stamp in getwings -- avoid image
  edge. 

- Extensive changes in halpha_clean_image.pro, changing bleed trail
  detection criterion, handling of bright star halos, etc. 

- Rotate images so Galactic center is in the center. 

- Mask stars brighter than V_Tycho of 5mag rather than trying to
  interpolate over (which usually makes a mess). 

- Change floor of halpha_poster.

- halpha_remove_star iterates fit to annulus with outlier rejection. 

- Refined healpix header format on advice of Gary Hinshaw and Janet Weiland.

- More hand-tuning of maskwings.  Still not entirely happy with this -
  it is too ad hoc. 


------------------------------------------------------------------------
First version is v0_9

All software available from dfink@astro.princeton.edu upon request. 
Please tell me if you use the software for any published work.