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/dh2e.hlp | 58 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 math/slalib/doc/dh2e.hlp (limited to 'math/slalib/doc/dh2e.hlp') diff --git a/math/slalib/doc/dh2e.hlp b/math/slalib/doc/dh2e.hlp new file mode 100644 index 00000000..965653c8 --- /dev/null +++ b/math/slalib/doc/dh2e.hlp @@ -0,0 +1,58 @@ +.help dh2e Jun99 "Slalib Package" +.nf + + SUBROUTINE slDH2E (AZ, EL, PHI, HA, DEC) + + - - - - - + D E 2 H + - - - - - + + Horizon to equatorial coordinates: Az,El to HA,Dec + + (double precision) + + Given: + AZ d azimuth + EL d elevation + PHI d observatory latitude + + Returned: + HA d hour angle + DEC d declination + + Notes: + + 1) All the arguments are angles in radians. + + 2) The sign convention for azimuth is north zero, east +pi/2. + + 3) HA is returned in the range +/-pi. Declination is returned + in the range +/-pi/2. + + 4) The latitude is (in principle) geodetic. In critical + applications, corrections for polar motion should be applied. + + 5) In some applications it will be important to specify the + correct type of elevation in order to produce the required + type of HA,Dec. In particular, it may be important to + distinguish between the elevation as affected by refraction, + which will yield the "observed" HA,Dec, and the elevation + in vacuo, which will yield the "topocentric" HA,Dec. If the + effects of diurnal aberration can be neglected, the + topocentric HA,Dec may be used as an approximation to the + "apparent" HA,Dec. + + 6) No range checking of arguments is done. + + 7) In applications which involve many such calculations, rather + than calling the present routine it will be more efficient to + use inline code, having previously computed fixed terms such + as sine and cosine of latitude. + + P.T.Wallace Starlink 21 February 1996 + + Copyright (C) 1996 Rutherford Appleton Laboratory + Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. + +.fi +.endhelp -- cgit