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Since "tfinder" still isn't working under 2.16, I've been using astrometry.net to add WCS to my headers. It's not as precise but it IS automatic, and usually works.

However, it uses a gnomic projection plus distortion term by default, and even if there is no distortion term added (by specifying "no tweak") the ISM in ximtool is not picking up the WCS: I get x and y rather than RA and DEC. ds9 as standalone (i.e., imags loaded directly rather than via IRAF) does pick it up nicely.

Here's what the relevant part of the headers look like:

WCSAXES = 2 / no comment
CTYPE1 = 'RA---TAN-SIP' / TAN (gnomic) projection + SIP distortions
CTYPE2 = 'DEC--TAN-SIP' / TAN (gnomic) projection + SIP distortions
EQUINOX = 2000.0 / Equatorial coordinates definition (yr)
LONPOLE = 180.0 / no comment
LATPOLE = 0.0 / no comment
CRVAL1 = 84.0237767385 / RA of reference point
CRVAL2 = -69.4124631648 / DEC of reference point
CRPIX1 = 1448.20217896 / X reference pixel
CRPIX2 = 959.46711731 / Y reference pixel
CUNIT1 = 'deg ' / X pixel scale units
CUNIT2 = 'deg ' / Y pixel scale units
CD1_1 = -0.000120485558231 / Transformation matrix
CD1_2 = 7.58317742643E-07 / no comment
CD2_1 = -6.78988056717E-07 / no comment
CD2_2 = -0.000121201422141 / no comment
IMAGEW = 2046 / Image width, in pixels.
IMAGEH = 3148 / Image height, in pixels.
A_ORDER = 1 / Polynomial order, axis 1
B_ORDER = 1 / Polynomial order, axis 2
AP_ORDER= 1 / Inv polynomial order, axis 1
AP_0_1 = -0 / no comment
AP_1_0 = -0 / no comment
BP_ORDER= 1 / Inv polynomial order, axis 2
BP_0_1 = -0 / no comment
BP_1_0 = -0 / no comment

Hi Phil,

The short answer is that SIP isn't yet supported by the WCS interface and so the ISM sees it as an unknown projection (DS9 uses the AST package for WCS). Since your distortion coeffs don't seem to be used then you might try just HEDITing the CTYPE keywords. You might also see Frank's reply to an earlier question at

https://iraf.net/forum/viewtopic.php?forum=5&showtopic=1463515

I'll look again at reviving TFINDER ......

thanks! Getting tfinder going again would be great. Rob was close, but never quite finished.