Initial commit

1 files changed, 73 insertions, 0 deletions

diff --git a/math/slalib/doc/rdplan.hlp b/math/slalib/doc/rdplan.hlp
new file mode 100644
index 00000000..5b9d560a
--- /dev/null
+++ b/math/slalib/doc/rdplan.hlp
@@ -0,0 +1,73 @@
+.help rdplan Jun99 "Slalib Package"
+.nf
+
+      SUBROUTINE slRDPL (DATE, NP, ELONG, PHI, RA, DEC, DIAM)
+
+     - - - - - - -
+      R D P L
+     - - - - - - -
+
+  Approximate topocentric apparent RA,Dec of a planet, and its
+  angular diameter.
+
+  Given:
+     DATE        d       MJD of observation (JD - 2400000.5)
+     NP          i       planet: 1 = Mercury
+                                 2 = Venus
+                                 3 = Moon
+                                 4 = Mars
+                                 5 = Jupiter
+                                 6 = Saturn
+                                 7 = Uranus
+                                 8 = Neptune
+                                 9 = Pluto
+                              else = Sun
+     ELONG,PHI   d       observer's east longitude and geodetic
+                                               latitude (radians)
+
+  Returned:
+     RA,DEC      d        RA, Dec (topocentric apparent, radians)
+     DIAM        d        angular diameter (equatorial, radians)
+
+  Notes:
+
+  1  The date is in a dynamical timescale (TDB, formerly ET) and is
+     in the form of a Modified Julian Date (JD-2400000.5).  For all
+     practical purposes, TT can be used instead of TDB, and for many
+     applications UT will do (except for the Moon).
+
+  2  The longitude and latitude allow correction for geocentric
+     parallax.  This is a major effect for the Moon, but in the
+     context of the limited accuracy of the present routine its
+     effect on planetary positions is small (negligible for the
+     outer planets).  Geocentric positions can be generated by
+     appropriate use of the routines slDMON and slPLNT.
+
+  3  The direction accuracy (arcsec, 1000-3000AD) is of order:
+
+            Sun              5
+            Mercury          2
+            Venus           10
+            Moon            30
+            Mars            50
+            Jupiter         90
+            Saturn          90
+            Uranus          90
+            Neptune         10
+            Pluto            1   (1885-2099AD only)
+
+     The angular diameter accuracy is about 0.4% for the Moon,
+     and 0.01% or better for the Sun and planets.
+
+  See the slPLNT routine for references.
+
+  Called: slGMST, slDT, slEPJ, slDMON, slPVOB, slPRNU,
+          slPLNT, slDMXV, slDC2S, slDA2P
+
+  P.T.Wallace   Starlink   26 May 1997
+
+  Copyright (C) 1997 Rutherford Appleton Laboratory
+  Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
+
+.fi
+.endhelp