From the menu: Setup → Observatory Settings

This dialog box can be reached from the menu by: Setup → Observatory, by the icon in the bar at the left hand side, or by Setup → All configuration options → All configuration options.

The Observatory settings dialog box has two tabs:

• Observatory
• Horizon

For a proper display of objects on the chart, don't forget to check your date / time settings as wel.

Define the location of the observation site to be used when calculating the altitude and the azimuth position of objects in the chart, rise and set time, solar system objects parallax, …

There are several ways to enter your location, but it is advisable to start with the “Internet Location” button which, if your computer is connected to the network, will found at least your country. The relevance of the result varies greatly across countries and network providers.

You can then refine the result with the “Observatory database” button which allows you to choose among several millions of place, see below for details.

You can also enter the name of your location and click the map to get an approximate position. Or if you want the optimal precision enter the coordinates and altitude indicated by GPS receiver.

It is important to select the correct time zone for your observatory because SkyCharts needs it to calculate the UT from your Daylight Savings setting. This is very important to do proper ephemeris calculations in order to display the right chart.
It is recommended to use the country time zone as it correct for DST for any epoch where the rules are know.
If you use the special GMT time zone, beware the hour offset sign is opposite of what you expect, zones west of GMT have a positive sign. See http://en.wikipedia.org/wiki/Tz_database#Area

If you frequently use this observation site you can add it to your favorites list with the Add button after all settings are right for you.

Observatory database

• Select your country
• Select your site from where you observe
  • To improve your choice, download the detail file of your country. If you want to copy this data to another computer without Internet access you can find them in the user data directory under the “tmp” folder.
  • Enter (a part of) the name of a near city in the search input box
  • Click the “Search” button
  • Select this near city from the pick-list in
  • Click the “vicinity” button
  • Now you can find names of places close to the city you previously selected in. Choose the one that suits you best.
  • The Location code help to solves homonyms place, such as a mountain and a river with the same name. Click in the box to view the list of codes.
• If the above is not sufficient, you can also add, modify or delete sites with “update” or “delete” button. To add a site, enter the name in the list and coordinates and click on “update”. Use a prefix (i.e obs_) to quickly retrieve your favorite observing place by entering this prefix to the search box.

When your chart is set to use the Alt-Az coordinate system, you can display your local horizon as a line or as an area. To read more about changing the coordinate system, click here.
You can load a local horizon file by setting the path.

You can write a file with a simple ASCII-editor like Wordpad or Vi to define your local horizon. As an example, you can open the file [installation directory]/data/horizon/horizon_Geneve.txt. As you can see from the file, the horizon is defined by a serie of records. Every line contains a pair of two values. The first value is the 'azimuth', the second is the 'altitude'. The units are degrees, where azimuth 0° is North and 90° is the Zenith. A dot (.) can be used as a decimal separator. You can put comment in your horizon file by lines that start with a mesh (#) character.

You can also use a picture for the horizon panorama. The image must be a PNG or BMP file of any size representing the full 360° panorama with an equirectangular projection. The horizon must be exactly at the middle height of the picture. The sky area must be set transparent (#FF00FF for BMP format). The left side of the picture is the East direction. If you use another orientation you must also give the offset angle. This function is compatible with the horizon made for Stellarium (type=spherical).

The other possibilities will be obvious from their description.
* Maybe you want to display objects below the horizon line.
* If your site is high on the mountain, maybe you want to simulate the horizon as a depressed line.

Above all, you can specify temperature, air pressure and humidity. This allows SkyChart to calculate and compensate for atmospheric refraction.

The last line is about some small correction for the Earth pole orientation. You can find the required prediction data in the latest IERS Bulletins A :

                     MJD      x(arcsec)   y(arcsec)   UT1-UTC(sec)              
       2014  1 31  56688       0.0245      0.3483     -0.12827         

For example for 2014 January 31 use X=0.0245 and Y=0.3483