[guide-user] Re: Horizon in Guide

Bernd Brinkmann Jan 24, 2000

Hallo Pierre,

I had this problem too when I started to edit my own horizon-file. The problem
is the following: the last and first point of a horizon obstruction is
connected by a straight line (say last point at az 150 deg ele -1 deg, first
point at 90 deg -1 deg). When viewing the whole sky ( fov 180 deg ) this
straight line will lie above the curved horizon line and you have the hole in
your horizon.
To avoid this do the following:
insert points in the line back from your end point to your start point at
-10 deg elevation all 10 deg of azimut. Then this straight connections will
always lie beneeth a curved horizon line.

Hope this helps.
Bernd

> I would like to drawn the horizon around my observatory with the
> horizon.dat file. I have walls, mountain and few hills that make
> obstruction. When I try to draw the walls of the observatory or some
> hills, it sometime appears in inverse, with a gap between the true
> horizon and the shape of the mountains or of the walls, as if the
> mountain or the wall stand alone in the sky!!!!. I take care to use
> the value of -1 as elevation to be sure that the mountain merge with
> the ground. Curiously, I didn't have this effect if I use the
> horizon.dat file provide with Guide. Could somebody help me to find
> out what I am doing wrong..
>
>
> Pierre Laporte
> Centre d'observation astronomique des Monts Notre-Dame
> Québec, Canada
Bernd Brinkmann
Herne, Germany

http://homepage.ruhr-uni-bochum.de/Bernd.A.Brinkmann/index.html