PAL Library The Starlink Positional Astronomy Library (PAL) is a C implementation of the SLALIB API. It is distributed under the GPL and uses the SOFA library wherever possible. V0.9.3 - Fix value of small in palFk524. Typo in port from Fortran had removed the "e" in the number. Thanks to @danielsf. - Add test for palFk524 V0.9.2 Thanks to Github user @nega0 for some BSD build fixes. More STARCONF_DEFAULT_PREFIX fixes for Scons file and for document building. New configure option: --with-erfa to allow the ERFA root location to be specified. V0.9.1 Now checks for STARCONF_DEFAULT_PREFIX environment variable when deciding whether a Starlink environment is present. This was more reliable than checking for STARLINK_DIR. V0.9.0 Add palPcd and palUnpcd V0.8.0 Add palEcleq V0.7.0 Add palPolmo. V0.6.0 New function, palVers, provides API access to the PAL version number as a string or integer. V0.5.1 The configure script was getting confused if run outside of Starlink without using --without-starlink. This was because $STARLINK is set in the script if it is not set and the configure script was assuming $STARLINK would be unset outside of a Starlink environment. The configure script now keys off $STARLINK_DIR but that may interact badly if STARLINK_DIR is set and --without-starlink is used. An experimental SConstruct build script is now available for users of scons. SUN/267 has been synced up with the associated source files. palIntin now respects the isblank configure check (as it should have done all along). Minor clean ups of some source prologues. V0.5.0 Now works with ERFA . The configure script has been modified to first check for ERFA and then check for SOFA. V0.4.0 New routines ported from SLA: palRefv, palAtmdsp New routine inherited from SOFA: palRefcoq Minimum SOFA version now 2013-12-02 palObs: Now includes telescope positions for APEX and NANTEN2 The autotools build scripts now require autoconf version 2.69. Thanks to Github user @nega0 for some BSD build fixes. A subset of the routines have been relicensed using LGPL to allow them to be included in the AST library. Thanks to Patrick Wallace for giving this permission. A paper on PAL has been published at ADASS: http://adsabs.harvard.edu/abs/2013ASPC..475..307J V0.3.0 Add refraction code and support palOap and palAop. For closer compatibility with SLA for testing purposes the refraction routines internally use clones of slaNutc, slaEqeqx, slaGmst and slaGeoc. Once the code has been verified further the PAL/SOFA routines will be used instead. Switching routines seems to change the results in palTest by about 0.05 arcsec. V0.2.0 Improve configure script when not in a Starlink build environment. Use ./configure --prefix=/path/to/install when Starlink is not available and add --without-starlink if Starlink is present but should not be used. V0.1.5 Explcitly look for libm rather than relying on SOFA to pull it in. V0.1.4 Check for isblank() function and fall back if it is missing. V0.1.3 Improve copysign() detection. V0.1.2 Check for copysign() c99 function and fall back if it is missing. V0.1.1 The palDrange function has been modified so that it now returns +PI if the supplied angle is +PI (previously, it returned -PI in these cases). V0.1.0 Initial release with sufficient SLALIB API for AST and the Astro::Coords perl module.