| ADD_DISTORT | Add SIP distortion parameters into a FITS header |
| AD2XY | Use astrometry structure to convert celestial to pixel coordinates |
| ADXY | Use FITS header to convert celestial (RA,Dec) to pixel coordinates |
| CONS_DEC | Obtain the X and Y coordinates of a line of constant declination |
| CONS_RA | Obtain the X and Y coordinates of a line of constant right ascension |
| EXTAST | EXTract ASTrometry parameters from a FITS header into an IDL structure |
| FITS_ADXY | Use a FITS file to convert from world to pixel coordinates |
| FITS_CD_FIX | Update obsolete representations of the CD matrix |
| FITS_XYAD | Use a FITS file to convert from pixel to world coordinates |
| GET_EQUINOX | Return a numeric equinox value from a FITS header |
| GETROT | GET ROTation and plate scale from a FITS header |
| GSSS_STDAST | Insert the closest tangent projection astrometry into an STScI Guidestar Survey Image |
| GSSSADXY | Convert RA, Dec to pixel coordinates for an STScI survey image |
| GSSSEXTAST | Extract astrometry parameters from an STScI Survey Image |
| GSSSXYAD | Convert pixel coordinates to RA, Dec for an STScI survey image |
| HASTROM | Rotate, Congrid, and/or shift an image until astrometry matches that in a reference FITS header. Used to align images. |
| HBOXAVE | Boxaverage an image and update astrometry in a FITS header |
| HCONGRID | CONGRID an image and update astrometry in a FITS header |
| HEULER | Convert between Galactic, celestial and ecliptic coordinates in FITS a header |
| HEXTRACT | Extract a subimage and update astrometry in a FITS header |
| HPRECESS | Precess the astrometry in a FITS header to a new equinox. |
| HREBIN | REBIN an image and update the astrometry in a FITS header |
| HREVERSE | Reverse an image about either dimension and update astrometry in a FITS header |
| HROT | Rotate an image and update astrometry in a FITS header. |
| HROTATE | Apply IDL ROTATE function and update astrometry in a FITS header |
| MAKE_ASTR | Build an astrometry structure from input parameter values |
| PRECESS_CD | Precess coordinate description (CD) matrix in a FITS header to a new equinox. Called by HPRECESS |
| PUTAST | Put astrometry parameters (e.g. rotation, plate scale) into a FITS header. |
| SIP_EVAL | Compute distorted coordinates given SIP (simple imaging polynomial) coefficients |
| SOLVE_ASTRO | Solve for an tangent-plane astrometric plate solution with optional distortion terms. |
| STARAST | Obtain an exact astrometry solution given the coordinates and plate position of 2 or 3 stars. |
| TNX_EVAL | Compute distorted coordinates give TNX (IRAF) projection |
| TPV_EVAL | Compute distorted coordinates given TPV (Tangent + PV_ polynomial) coefficients |
| UPDATE_DISTORT | Update SIP astrometry coefficients for a linear transformation |
| WCS_CHECK_CTYPE | Check that pair of CTYPE parameters conform to WCS format. |
| WCS_GETPOLE | Compute the coordinates of the native pole for non-polar projection |
| WCSSPH2XY | Convert between longitude,latitude to X,Y angular coordinates for 25 different map projection types |
| WCSXY2SPH | Inverse of WCSSPH2XY |
| WCS_DEMO | Demo program for WCSSPH2XY and WCSXY2SPH |
| WCS_ROTATE | Rotate between standard (e.g. celestial) and native coordinates |
| XYAD | Use FITS header to convert pixel (X,Y) to celestial(RA, Dec) coordinates |
| XY2AD | Use astrometry structure to convert pixel to celestial coordinates |
| XYXY | Convert X,Y values on one image to X,Y values in another image using astrometry in the FITS headers |