1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
.help dbear Jun99 "Slalib Package"
.nf
DOUBLE PRECISION FUNCTION slDBER (A1, B1, A2, B2)
- - - - - -
D B E R
- - - - - -
Bearing (position angle) of one point on a sphere relative to another
(double precision)
Given:
A1,B1 d spherical coordinates of one point
A2,B2 d spherical coordinates of the other point
(The spherical coordinates are RA,Dec, Long,Lat etc, in radians.)
The result is the bearing (position angle), in radians, of point
A2,B2 as seen from point A1,B1. It is in the range +/- pi. If
A2,B2 is due east of A1,B1 the bearing is +pi/2. Zero is returned
if the two points are coincident.
P.T.Wallace Starlink 23 March 1991
Copyright (C) 1995 Rutherford Appleton Laboratory
Copyright (C) 1995 Association of Universities for Research in Astronomy Inc.
.fi
.endhelp
|
