sky2xy
Examples

1. Print x-y coordinates for 2 sky positions in image test.fts: sky2xy test.fts 9:55:41.600 +69:00:27.99 9:54:53.258 +69:03:49.30; 9:55:41.600 +69:00:27.99 -> 324.536 419.073; 9:54:53.258 +69:03:49.30 -> 689.350 704.221
2. Print x-y coordinates for sky position just off image and outside of projection in image test.fts.
Positions more than 90 degrees from the tangent point are undefined in plate-tangent (TAN) projections, but it is quite possible for the tangent point to be off an image, as for the image of one detector from a detector array.: sky2xy test.fts 149.10704 68.92327 J2000 320 -31 FK5; 149.10704 68.92327 J2000 -> -10.002 -10.022 1 (off image); 320 -31 FK5 -> 0.000 0.000 1 (offscale)
3. Print x-y coordinates in image test.fts for sky positions in file skyfile.: sky2xy -v test.fts @skyfile; 9:55:41.600 +69:00:27.99 -> 324.536 419.073; 9:54:53.258 +69:03:49.30 -> 689.350 704.221; 9:54:31.983 +69:01:25.55 -> 851.482 502.482; 9:54:42.238 +69:05:44.77 -> 771.670 867.499