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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/doc/ampqk.hlp | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'math/slalib/doc/ampqk.hlp')
-rw-r--r-- | math/slalib/doc/ampqk.hlp | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/math/slalib/doc/ampqk.hlp b/math/slalib/doc/ampqk.hlp new file mode 100644 index 00000000..a4b8dee6 --- /dev/null +++ b/math/slalib/doc/ampqk.hlp @@ -0,0 +1,65 @@ +.help ampqk Jun99 "Slalib Package" +.nf + + SUBROUTINE slAMPQ (RA, DA, AMPRMS, RM, DM) + + - - - - - - + A M P Q + - - - - - - + + Convert star RA,Dec from geocentric apparent to mean place + + The mean coordinate system is the post IAU 1976 system, + loosely called FK5. + + Use of this routine is appropriate when efficiency is important + and where many star positions are all to be transformed for + one epoch and equinox. The star-independent parameters can be + obtained by calling the slMAPA routine. + + Given: + RA d apparent RA (radians) + DA d apparent Dec (radians) + + AMPRMS d(21) star-independent mean-to-apparent parameters: + + (1) time interval for proper motion (Julian years) + (2-4) barycentric position of the Earth (AU) + (5-7) heliocentric direction of the Earth (unit vector) + (8) (grav rad Sun)*2/(Sun-Earth distance) + (9-11) ABV: barycentric Earth velocity in units of c + (12) sqrt(1-v**2) where v=modulus(ABV) + (13-21) precession/nutation (3,3) matrix + + Returned: + RM d mean RA (radians) + DM d mean Dec (radians) + + References: + 1984 Astronomical Almanac, pp B39-B41. + (also Lederle & Schwan, Astron. Astrophys. 134, + 1-6, 1984) + + Notes: + + 1) The accuracy is limited by the routine slEVP, called + by slMAPA, which computes the Earth position and + velocity using the methods of Stumpff. The maximum + error is about 0.3 milliarcsecond. + + 2) Iterative techniques are used for the aberration and + light deflection corrections so that the routines + slAMP (or slAMPQ) and slMAP (or slMAPQ) are + accurate inverses; even at the edge of the Sun's disc + the discrepancy is only about 1 nanoarcsecond. + + Called: slDS2C, slDIMV, slDVDV, slDVN, slDC2S, + slDA2P + + P.T.Wallace Starlink 21 June 1993 + + Copyright (C) 1995 Rutherford Appleton Laboratory + Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. + +.fi +.endhelp |