From d54fe7c1f704a63824c5bfa0ece65245572e9b27 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 4 Mar 2015 21:21:30 -0500
Subject: Initial commit

---
 src/slalib/atms.f | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 src/slalib/atms.f

(limited to 'src/slalib/atms.f')

diff --git a/src/slalib/atms.f b/src/slalib/atms.f
new file mode 100644
index 0000000..3b991f4
--- /dev/null
+++ b/src/slalib/atms.f
@@ -0,0 +1,40 @@
+      SUBROUTINE sla__ATMS (RT, TT, DNT, GAMAL, R, DN, RDNDR)
+*+
+*     - - - - -
+*      A T M S
+*     - - - - -
+*
+*  Internal routine used by REFRO
+*
+*  Refractive index and derivative with respect to height for the
+*  stratosphere.
+*
+*  Given:
+*    RT      d    height of tropopause from centre of the Earth (metre)
+*    TT      d    temperature at the tropopause (deg K)
+*    DNT     d    refractive index at the tropopause
+*    GAMAL   d    constant of the atmospheric model = G*MD/R
+*    R       d    current distance from the centre of the Earth (metre)
+*
+*  Returned:
+*    DN      d    refractive index at R
+*    RDNDR   d    R * rate the refractive index is changing at R
+*
+*  P.T.Wallace   Starlink   14 July 1995
+*
+*  Copyright (C) 1995 Rutherford Appleton Laboratory
+*-
+
+      IMPLICIT NONE
+
+      DOUBLE PRECISION RT,TT,DNT,GAMAL,R,DN,RDNDR
+
+      DOUBLE PRECISION B,W
+
+
+      B = GAMAL/TT
+      W = (DNT-1D0)*EXP(-B*(R-RT))
+      DN = 1D0+W
+      RDNDR = -R*B*W
+
+      END
-- 
cgit