procedure hdf_wcs_fix (pc1,wf2,wf3,wf4,wcsup)

# Update WCS in HDF version 2 release images to match the 
# coordinate system (RA, Dec) used for the HDF catalog published 
# in Williams et al. 1996, AJ 112, 1335.
#
# M. Dickinson, 30 Oct. 1996
# requires that the 'proto' package be loaded.

string	pc1	{prompt="HDF v2 PC1 image(s) for WCS correction"}
string	wf2	{prompt="HDF v2 WF2 image(s) for WCS correction"}
string	wf3	{prompt="HDF v2 WF3 image(s) for WCS correction"}
string	wf4	{prompt="HDF v2 WF4 image(s) for WCS correction"}
bool	wcsup	{yes,prompt="Update RA, Dec zeropoint to match HDF v2 catalog?"}
struct	*fread

begin

	string	pc1im, wf2im, wf3im, wf4im
	string	tempfile, image
	bool	dowcsup

	print (" ")
	print ("This program will modify the world coordinate system (WCS)")
	print ("in the image headers of the selected files.  These images")
	print ("MUST be the HDF version 2 drizzled images as obtained from")
	print ("STScI, or at least must have the same pixel coordinates and")
	print ("orientations as those STScI version 2 release images.")
	print (" ")

# Get query parameters

	pc1im = pc1
	wf2im = wf2
	wf3im = wf3
	wf4im = wf4

	dowcsup = wcsup

# Correct PC1 images

	tempfile = mktemp("tmp$hdfwcsfix")
	sections (pc1im,option="fullname",>tempfile)
	fread = tempfile
	while (fscan(fread,image) != EOF) {
	      hedit (image,"CTYPE1","RA---TAN",add+,ver-,up+,show+)
	      hedit (image,"CTYPE2","DEC--TAN",add+,ver-,up+,show+)
	      if (dowcsup) {
	      	wcsedit (image,"crval","189.18491442038","1","",
			wcs="world",inter-,verbose+,up+)
	      	wcsedit (image,"crval","62.219760477133","2","",
			wcs="world",inter-,verbose+,up+)
	      }
	}
	delete (tempfile,ver-)

# Correct WF2 images

	tempfile = mktemp("tmp$hdfwcsfix")
	sections (wf2im,option="fullname",>tempfile)
	fread = tempfile
	while (fscan(fread,image) != EOF) {
	      hedit (image,"CTYPE1","RA---TAN",add+,ver-,up+,show+)
	      hedit (image,"CTYPE2","DEC--TAN",add+,ver-,up+,show+)
	      if (dowcsup) {
	      	wcsedit (image,"crval","189.21043170410","1","",
			wcs="world",inter-,verbose+,up+)
	      	wcsedit (image,"crval","62.231066368033","2","",
			wcs="world",inter-,verbose+,up+)
	      }
	}
	delete (tempfile,ver-)

# Correct WF3 images

	tempfile = mktemp("tmp$hdfwcsfix")
	sections (wf3im,option="fullname",>tempfile)
	fread = tempfile
	while (fscan(fread,image) != EOF) {
	      hedit (image,"CTYPE1","RA---TAN",add+,ver-,up+,show+)
	      hedit (image,"CTYPE2","DEC--TAN",add+,ver-,up+,show+)
	      if (dowcsup) {
	      	wcsedit (image,"crval","189.22912064331","1","",
			wcs="world",inter-,verbose+,up+)
	      	wcsedit (image,"crval","62.212189763997","2","",
			wcs="world",inter-,verbose+,up+)
	      }
	}
	delete (tempfile,ver-)

# Correct WF4 images

	tempfile = mktemp("tmp$hdfwcsfix")
	sections (wf4im,option="fullname",>tempfile)
	fread = tempfile
	while (fscan(fread,image) != EOF) {
	      hedit (image,"CTYPE1","RA---TAN",add+,ver-,up+,show+)
	      hedit (image,"CTYPE2","DEC--TAN",add+,ver-,up+,show+)
	      if (dowcsup) {
	      	wcsedit (image,"crval","189.18661365727","1","",
			wcs="world",inter-,verbose+,up+)
	      	wcsedit (image,"crval","62.203675138200","2","",
			wcs="world",inter-,verbose+,up+)
	      }
	}
	delete (tempfile,ver-)

	fread = ""

end