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author | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
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committer | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
commit | 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch) | |
tree | 4464880c571602d54f6ae114729bf62a89518057 /math/slalib/read.me | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
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diff --git a/math/slalib/read.me b/math/slalib/read.me new file mode 100644 index 00000000..0b216cb6 --- /dev/null +++ b/math/slalib/read.me @@ -0,0 +1,443 @@ +READ.ME + +Revision date 14 June 2005 SLALIB Version 2.5-2 + +----------------------------------------------------------------------- + +FILES IN THE ORIGINAL SOURCE DIRECTORY (UNIX) + + read.me this file + *.f Fortran source (separate modules) + *.vax Fortran source for VAX/VMS + *.cnvx Fortran source for Convex + *.mips Fortran source for DECstation + *.sun4 Fortran source for Sun SPARCstation + *.lnx Fortran source for Linux + *.pcm Microsoft Fortran source for PC + *.c C functions needed for Linux version + sla.news NEWS item for latest release + make_file Unix make file + mk C-shell script to run make + sun67.tex document + +----------------------------------------------------------------------- + + Copyright (C) 1995-2005 Rutherford Appleton Laboratory + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + + +----------------------------------------------------------------------- + +PORTING FORTRAN SLALIB TO OTHER SYSTEMS + +FORTRAN SLALIB runs on VAX (VMS), PC (Linux+f2c), PC (Microsoft FORTRAN), +Convex (ConvexOS), DECstation (Ultrix), DEC Alpha (OSF-1) and Sun +SPARCstation (SunOS and Solaris). + +For most platforms, the required changes are confined to these routines: + + sla_GRESID + sla_RANDOM + sla_WAIT + +VAX, CONVEX, DECSTATION/ALPHA, SUN & PC + +Versions suitable for the above platforms are supplied in the +development directory as *.vax, *,cnvx, *.mips, *.sun4, *.pcm and +*.lnx respectively. + + +----------------------------------------------------------------------- + +LATEST RELEASE INFORMATION + +The latest release of SLALIB includes the following changes (most recent +at the end): + +* In sla_RCC, the topocentric term of coefficient 1.3184D-10 sec + had the wrong sign. Minus is correct. + +* The IAU decided in 1991 to rename the Terrestrial Dynamical + Time, TDT, which is now called "Terrestrial Time" or TT. + Appropriate changes have been made in the SLALIB documentation. + The same IAU resolutions introduced the timescales TCG and TCB; + there are at present no SLALIB routines to handle these new + timescales. + +* The Keck 1 Telescope has been added to sla_OBS. + +* The handling of the random-number seed in the PC versions of + sla_RANDOM and sla_GRESID was flawed and has been improved. + +* The UTC leap second at the end of June 1993 has been added to the + routine sla_DAT. Existing applications which call sla_DAT or + sla_DTT require relinking. + +* Some unnecessary code in sla_AMPQK has been removed. + +* Minor reorganization of the sla_REFRO code has led to an improvement + in speed of about 20%, and precautions have been taken against + potential arithmetic errors. + +* There have been small revisions to sla_FK425 and sla_FK524. The + results are not significantly affected, except in the pathological + case of large proper motion combined with immense distance, where + sla_FK524 could produce erroneous radial velocity values. The + latest versions are close to the algorithms published in the 1992 + Explanatory Supplement to the Astronomical Almanac. + +* The leap second at the end of June 1994 has been added to sla_DAT. + +* THE SLA_RVLSR ROUTINE HAS BEEN RETIRED. Its place has been taken + by two new routines: sla_RVLSRK and sla_RVLSRD. The original + sla_RVLSR had used a "kinematical" LSR. When this was later changed + to a "dynamical" LSR for (what seemed liked good reasons at the time), + the small differences were noticed by spectral-line radio observers, + who had to fall back on old copies of the routine to remain consistent + with existing practice. The new routines provide both sorts of LSR: + sla_RVLSRK uses a kinematical LSR and sla_RVLSRD uses the dynamical LSR. + +* The sla_PA routine (computation of parallactic angle) used an + unnecessarily complicated formulation, which has been simplified. + The results are unaffected. + +* The sla_ZD routine (computation of zenith distance) used a + straightforward cosine-formula-based method, which suffered from + decreased accuracy near the zenith. A better, vector-derived, + formulation has been substituted, without materially affecting + the results. Because sla_ZD is double precision, the old + formulation was always adequate; however, had anyone transcribed + the code in single precision errors approaching 1 arcmin could + have resulted. The new formulation delivers good results all + over the sky even in a single precision version. + +* Routines have been added to transform equatorial coordinates + (HA,Dec) to horizon coordinates (Az,El) and back. Single and + double precision are both supported. The routines are called + sla_E2H, sla_DE2H, sla_H2E, sla_DH2E. + +* A new routine has been added to the tangent-plane projection set. + The single and double precision versions are called sla_TPRD and + sla_DTPRD respectively. Given the RA,Dec of a star and its + xi,eta coordinates, the routine determines the "plate centre". + +* The existing routine sla_PREC for obtaining the precession matrix + uses the official IAU model and should continue to be used for + canonical purposes. A new version, called sla_PRECL, uses a + more up-to-date model which delivers better accuracy, especially + over intervals of millennia. + +* The routine sla_PVOBS was returning velocities in AU per sidereal + second rather than per UT second. This has been corrected. The + maximum error was equivalent to about 0.001 km/s. + +* In sla_MAPQK and sla_MAPQKZ, the area within which the gravitional + light-deflection term is restrained has been extended from its + original 300 arcsec radius to about 920 arcsec, just inside the + Sun's disc. + +* A chapter of explanation, with examples, has been added to SUN/67, + which has also undergone various cosmetic revisions. + +* There were two discrepancies between the documentation of sla_DCMPF + (program comments and SUN/67) and the code. The first was that the + formulae for the nonperpendicularity used PERP instead of PERP/2; + the documentation has been corrected. The other was that the + documentation showed the zero point corrections being applied first, + whereas the code returned zero point corrections corresponding to + being applied last. The code has been corrected to match the + documentation. + +* The C module slaCldj gave incorrect answers for dates during + January and February. The error, which did not affect the Fortran + version, has been corrected. + +* THE CALLS FOR sla_TPRD AND sla_DTPRD HAS BEEN CHANGED. An integer + status argument has been added; non-zero means the supplied RA,Dec + and Xi,Eta describe an impossible case. (This can only happen + near the pole and with non-zero Xi.) Also, a slightly neater + formulation has been introduced. + +* Three new routines have been added. sla_ALTAZ takes a star's HA,Dec + and produces position, velocity and acceleration for azimuth, + elevation and parallactic angle. sla_PDA2H predicts the HA at which + a given azimuth will be reached. sla_PDQ2H does the same for + position angle. + +* In the sla_OBS routine, the wrong sign was returned for the Perkins + 72 inch telescope at Lowell - fixed. + +* A revised model for the equation of the equinoxes has been + installed in sla_EQEQX, in line with recent IAU resolutions. The + change amounts to less than 3 mas. + +* A bug in sla_DFLTIN has been corrected. A negative number following + an E- or D-format number without intervening spaces lost its sign. + +* Four stations have been added to sla_OBS: + + TAUTENBERG Tautenberg 1.34 metre Schmidt + PALOMAR48 Palomar 48-inch Schmidt + UKST UK 1.2 metre Schmidt, Siding Spring + KISO Kiso 1.05 metre Schmidt, Japan + ESOSCHMIDT ESO 1 metre Schmidt, La Silla + +* The sla_EARTH and sla_MOON routines could give an integer divide by zero + for years before 1 BC. This has been corrected. + +* sla_CALYD (provided to support the sla_EARTH and sla_MOON routines) + has been upgraded to work outside the interval 1900 March 1 to + 2100 February 28. The status value indicating dates outside that + range has been dropped; a new error value for year before -4711 + has been introduced. + +* A new routine, sla_CLYD, has been added. It is a version of sla_CALYD + without the century-default feature and is to enable 1st-century + dates to be supplied to sla_EARTH and sla_MOON. + +* Two new routines, sla_PLANET and sla_RDPLAN, have been added, which + compute approximate planetary ephemerides. + +* A new routine, sla_DMOON, implements the same (Meeus) model as the + sla_MOON routine, but in full and in double precision. The time + argument is a straightforward MJD rather than sla_MOON's year and + day-in-year. + +* The sla_REFRO code has been speeded up by a factor of two (and is + also clearer). + +* sla_REFV and sla_REFZ have, in different ways, been made more accurate + for cases close to the horizon. The improvement to sla_REFV is + relatively modest, but sla_REFZ is now capable of delivering useful + results for rise/set phenomena. + +* sla_AOPQK has been speeded up for low-elevation cases. + +* Versions of the tangent-plane routines working directly in x,y,z + instead of spherical coordinates have been added. They may be + faster in some applications. The routines are sla_DV2TP, sla_V2TP, + sla_DTP2V, sla_TP2V, sla_DTPXYZ, sla_TPXYZ. + +* The coordinates of the Australia Telescope Compact Array have been + added to sla_OBS. The name is 'ATCA'. + +* Despite their recent introduction THE ROUTINES sla_DTPRD, sla_DTPXYZ, + sla_TPRD AND sla_TPXYZ HAVE BEEN WITHDRAWN. They have been replaced + by the new routines sla_DTPS2C, sla_DTPV2C, sla_TPS2C and sla_TPV2C. + These are functionally equivalent to the earlier routines but return + two solutions instead of one: the second solution can arise near a + pole. + +* The UTC leap second at the end of 1995 has been added to sla_DAT. + +* The refraction routine sla_REFRO has been extensively revised. The + principal motivation was to improve the radio predictions by + introducing better humidity models. The models previously in + use had been entirely adequate for the optical case, for which + they had been devised, but improved models were required for + the radio case. None of the changes significantly affects the + optical results with respect to the earlier version of the sla_REFRO + routine. For example, at 70 deg zenith distance the new version + agrees with the old version to better than 0.05 arcsec for any + reasonable combination of parameters. However, the improved + water-vapour expressions do make a significant difference in the + radio band, at 70 deg zenith distance reaching almost 4 arcsec + for a hot, humid, low-altitude site during a period of low pressure. + +* There was a bug in slaRdplan, the (private) C version of sla_RDPLAN. + The answers were unaffected but there could be floating-point + problems on some platforms. + +* A new routine has been added, sla_GMSTA. This gives greater numerical + precision than the existing GMST function by allowing the date and + time to be specified separately rather than as a single MJD. + +* Measures taken in sla_MAPQK to avoid trouble when processing Solar + positions had not been carried through into sla_MAPQKZ. The two + routines now use the same strategy. + +* In sla_REFRO, at zenith distances well beyond 90 deg and under some + conditions, it was possible to encounter arithmetic errors due to + failure of the tropospheric model-atmosphere to deliver sensible + temperatures. This is inherent in the published algorithm. To + avoid the problem, the temperature delivered by the model has been + constrained to the range 200 to 320 deg K. + +* A new routine has been added, sla_ATMDSP, for rapidly recalculating + the A,B refraction coefficients for different wavelengths. + +* The first UTC leap-second date in the sla_DAT routine was one day early. + This will have had no effect on the results for more recent epochs. + +* slaObs, the C version of sla_OBS, had some problems related to character + string handling. A call using the "number" option retured an invalid + station ID, and station ID and name strings of the stipulated 10 + and 40 character lengths were improperly terminated. + +* A new routine, sla_POLMO has been added. This is a specialist tool + to do with Earth polar motion. + +* sla_DC62S and sla_CC62S could give floating point errors if vectors in + unlikely units were supplied. The handling of difficult cases has + been improved. + +* Support for Linux has been added. + +* slaRefreo, the C version of sla_REFRO, was not re-entrant. It is now; + there has been a small (4%) speed penalty. + +* The C routines slaRandom, slaGresid and slaWait have been dropped. + They could not easily be made re-entrant and posed perennial platform- + dependency problems. + +* The value for the arcsec to radians factor in several routines + had an incorrect (and superfluous) 19th digit, which has been + removed. + +* There was a minor bug in sla_DV2TP and sla_V2TP, to do with protection + against the special case where the tangent point is the pole. + +* In sla_OBS, the position of the Parkes radiotelescope has been revised, + and the ATNF Mopra observatory has been added. + +* Two new routines have been added. sla_PAV (single precision) and + sla_DPAV (double precision) are like sla_BEAR and sla_DBEAR but start + with direction cosines rather than spherical coordinates - they return + the position angle of one point with respect to the other. + +* slaRefro, the C version of sla_REFRO, still wasn't re-entrant, but is + now. + +* slaDtf2d, the C version of sla_DTF2D, used to accept 60.0 in the seconds + field; this has been corrected. + +* The sla_PLANET and sla_RDPLAN routines now include Pluto. The ephemeris + is accurate (sub-arcsecond) but covers the 20th and 21st centuries + only. + + !!! IMPORTANT NOTE !!! + + sla_RDPLAN used to interpret any planet number outside the range 1-8 + as meaning the Sun. The new version uses planet number 9. Existing + programs using 9 for the Sun should be changed to use 0. The rule + has not been changed, except that the range is now 1-9 instead of + 1-8, as it is unlikely that the equivalent problem will arise in the + future. + +* Two new routines have been added, sla_PLANEL and sla_PLANTE. They are + analogues of sla_PLANET and sla_RDPLAN but for the case where orbital + elements are available. They can be used for predicting the + positions of asteroids and comets, and, if up-to-date osculating + elements are supplied, more accurate positions for the major + planets than can be provided through the sla_PLANET and sla_RDPLAN + routines. + +* The sla_REFRO routine could give inaccurate results for low temperatures + (subzero C). This was caused by over-cautious defensive programming, + which prevented the tropospheric temperature falling below 200 K. + +* A new routine has been added, sla_REFCOQ. This calculates the coefficients + of a two-term refraction model. It complements the existing sla_REFCO + routine, being much faster at the expense of some accuracy. + +* The 1997 July 1 UTC leap second has been added to the sla_DAT routine. + +* A bug in slaSvd, the C version of sla_SVD, caused occasional false + indications of ill-conditioning. The results of least-squares + fits do not seem to have been affected. The Fortran version did not + have the bug. + +* The Subaru telescope (Japanese National 8-metre telescope, Mauna Kea) + has been added to the sla_OBS routine. + +* The sla_DAT routine has been extended back to the inception of UTC in + 1960. + +* The "earliest date possible" in DJCL sla_was two days out (disagreeing + with sla_DJCAL, which had the correct value). + +* The sla_GMSTA code has been improved. + +* A new routine, sla_PV2EL, takes a heliocentric J2000 equatorial position + and velocity and produces the equivalent set of osculating elements. + +* The 1999 January 1 UTC leap second has been added to the sla_DAT routine. + +* Four new routines have been introduced which transform between the + FK5 system and the ICRS (Hipparcos) system. sla_FK52H and sla_H2FK5 + transform star positions and proper motions from FK5 coordinates to + Hipparcos coordinates and vice versa. sla_FK5HZ and sla_HFK5Z do the + same but for the case where the Hipparcos proper motions are zero. + +* Six new routines have been introduced for dealing with orbital elements. + Four of them (sla_EL2UE, sla_PV2UE, sla_UE2EL and sla_UE2PV) provide + applications with direct access to the "universal variables" method + that was already being used internally. Compared with using conventional + (angular) elements and solving Kepler's equation, the universal variables + approach has a number of advantages, including better handling of near- + parabolic orbits and greater efficiency. The remaining two routines + (sla_PERTEL and sla_PERTUE) generate updated elements by applying + major-planet perturbations. The new elements can then be used to + predict positions that are much more accurate. For minor planets, + sub-arcsecond accuracy over a decade is achievable. + +* Several observatory sites have been added to the OBS routine: CFHT, + Keck 2, Gemini North, FCRAO, IRTF and CSO. The coordinates for all + the Mauna Kea sites have been updated in accordance with recent aerial + photography results made available by the Institute for Astronomy, + University of Hawaii. + +* A bug in sla_DAT has been corrected. It used to give incorrect + results for dates in the first 54 days of 1972. + +* There are new routines for generating permutations (sla_PERMUT) and + combinations (sla_COMBN). + +* There was a bug in sla_PM for star data using Julian epochs (i.e. all + modern data). The treatment of radial velocity was correct for + Besselian epochs but wrong for Julian epochs. This had only a tiny + effect on a handful of nearby stars. The new version assumes Julian + epochs when interpreting the radial velocity. If the data are old- + style, using Besselian epochs, you have to scale the radial velocity + by 365.2422/365.25 first. + +* There was a bug in sla_RCC which meant the diurnal terms were being + calculated incorrectly, leading to errors of up to about 4 microsec. + +* Two new routines have been added, sla_DSEPV and sla_SEPV. These are + analogues of the existing routines sla_DSEP and sla_SEP, but accept + [x,y,z] vectors instead of spherical coordinates. + +* The sla_UNPCD routine used to be approximate but now is rigorous. + +* The four VLTs and Gemini South have been added to sla_OBS. + +* An additional Earth position/velocity routine, sla_EPV, has been + added. It is bigger and slower than sla_EVP but much more accurate. + Position accuracy is a few km; velocity accuracy is a few mm/s. + The sla_PERTUE and sla_PLANTU routines now call this routine in + order to deliver better predictions for near-Earth objects. + +* There was a bug in sla_DSEPV. For the unique case of two precisely + antipodal vectors zero was returned instead of pi. + +----------------------------------------------------------------------- + + + P.T.Wallace + + ptw@star.rl.ac.uk + +44-1235-44-5372 |