From 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 Mon Sep 17 00:00:00 2001 From: Joe Hunkeler Date: Tue, 11 Aug 2015 16:51:37 -0400 Subject: Repatch (from linux) of OSX IRAF --- math/slalib/doc/earth.hlp | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 math/slalib/doc/earth.hlp (limited to 'math/slalib/doc/earth.hlp') diff --git a/math/slalib/doc/earth.hlp b/math/slalib/doc/earth.hlp new file mode 100644 index 00000000..ea0eccd6 --- /dev/null +++ b/math/slalib/doc/earth.hlp @@ -0,0 +1,44 @@ +.help earth Jun99 "Slalib Package" +.nf + + SUBROUTINE slERTH (IY, ID, FD, PV) + + - - - - - - + E R T H + - - - - - - + + Approximate heliocentric position and velocity of the Earth + + Given: + IY I year + ID I day in year (1 = Jan 1st) + FD R fraction of day + + Returned: + PV R(6) Earth position & velocity vector + + Notes: + + 1 The date and time is TDB (loosely ET) in a Julian calendar + which has been aligned to the ordinary Gregorian + calendar for the interval 1900 March 1 to 2100 February 28. + The year and day can be obtained by calling slCAYD or + slCLYD. + + 2 The Earth heliocentric 6-vector is mean equator and equinox + of date. Position part, PV(1-3), is in AU; velocity part, + PV(4-6), is in AU/sec. + + 3 Max/RMS errors 1950-2050: + 13/5 E-5 AU = 19200/7600 km in position + 47/26 E-10 AU/s = 0.0070/0.0039 km/s in speed + + 4 More precise results are obtainable with the routine slEVP. + + P.T.Wallace Starlink 23 November 1994 + + Copyright (C) 1995 Rutherford Appleton Laboratory + Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. + +.fi +.endhelp -- cgit