What is Gnome Predict?
Gnome Predict is a real time satellite tracking program for Gnome, based on the tracking engine of John Magliacane's excellent satellite tracker Predict (http://www.qsl.net/kd2bd/predict.html). In the beginning (v. 0.1), Gnome Predict was just a GUI client using Predict's socket interface but as of version 0.2, the tracking code from Predict has been included directly into Gnome Predict so the program doesn't need a running Predict server anymore. This decision has been made due to performance problems using the socket interface.
Gnome Predict aims to include the following features as we move towards version 1.0:
- Be able to track a large number of satellites (only limited by the physical memory of the computer)
- Track for several groundstations, not just one.
- Show the satellite data using various visualization modules (lists, maps, sky, etc.)
- Predict upcomming passes for the satellites.
- Automatically update element sets when newer sets are available
- Control your receiver/transmitter and antenna rotor using the hamlib libraries (http://sourceforge.net/projects/hamlib)
- Advanced schedule manager for unattended monitoring of satellites.
- Any desirable feature that is missing from other programs (feel free to submit your ideas)
STATUS
At the present the following features are implemented:
- Tracking a large number of satellites (the limit is set to 500 but it can be changed by editing a single line in defaults.h) The tracking code is FAST - tracking 50 satellites 10 times a second gives a CPU load of about 5% on an ancient 120MHz Petium.
- Element sets can be updated automatically from the web.
- Displays the tracking data in lists or on maps. The lists can be sorted in ascending or descending order by clicking on the column titles and the satellites can be highlighted according to their status. The maps can be saved to a file in any of the common graphic formats (jpg, png, xpm ...) or printed using gnome-print. The map modules can use different background maps.
- The lists and maps can edited after creation.
- You can have many lists and maps open at the same either in a notebook or in their own windows.
- Show/Print/Save upcomming passes for satellites showing AOS and LOS times.
- Show/Print/Save/Plot detailed information about an upcoming pass. The polar plot can also be saved as an image.
- The user can configure many ground station locations and switch between them at runtime. Ground station data can be entered manually by specifying geographical coordinates or Mainhead locator squares or by selecting from a list of more that 2000 known locations.
REQUIREMENTS
Gnome Predict is written using the Gtk+/Gnome widget set, so you will need gnome-libs and gnomeui-libs v 1.4 installed on your system (they are usually called development packages when you install Linux from a distribution). You don't have to run Gnome as desktop manager, you only need the libraries installed and configured properly. Furthermore, as of version 0.3, you will also need GConf, gnome-vfs, gnome-print and the G Application Library (libgal) and their respective development packages. They are all shipped with any modern Linux distribution. Please refer to the INSTALL file for details.
USING GNOME PREDICT
When you start Gnome Predict for the very first time, it will ask you to specify your location (QTH). You will be given the possibility to select a city from a list or to enter the lattitude and longitude or Mainhead locator square by yourself. The information will be stored and you can edit this information at any later time if you whish to correct your location. When done, the main window should pop up, and you should be able to create new lists and maps from the shortcut bar on left side of the main window.
UPGRADING FROM 0.3
If you are using Gnome Predict 0.3.2 or earlier versions regularly, you should note that Gnome Predict 0.4 uses different data files and is not compatible with earlier versions. There should be no problems installing the new version but some bugs can be expected. If you want to keep Gnome Predict 0.3.x to be on the safe side, you should reaname the old binary /usr/local/bin/gpredict to something else like /usr/local/bin/gpredict03. It is not possible to install Gnome Predict 0.4 into a different location.
UPDATING ELEMENT SETS
As of version 0.4, it is possible to update the element sets from the web. The element sets are stored in $HOME/.gpredict/tle and the files are identical to those that can be found at Celestrak, http://www.celestrak.com, unless you have modified them. By selecting the "Edit->Update TLE" menu item in the menu bar, you can update these files automatically at runtime.
USER MAPS
As of version 0.4 you can use different background maps. Gnome Predict comes bundled with 5 different maps, but you can also use your own maps if you copy them to the $HOME/.gpredict/maps/ directory. Unfortunately, the program can only use fixed sized maps, thus the maps will be scaled to 800x400 pixels. You can however modify this fixed size by editing the satmap.h file in the src/ subdirectory and recompiling the program.
EXPERIMENTAL FEATURES
Saving and printing graphics (maps or track plots) is very experimental! To have them work right, you must make sure, that no other windows are covering the area of interest when you push the "Print" or "Save" buttons. This will hopefully be changed in the future.
LICENSE AND WARRANTY
Gnome Predict is released under the GNU General Public License and comes with NO WARRANTY whatsoever (well, maybe except that it works for us). See the COPYING file for details. If you have problems installing or using Gnome Predict, feel free to ask for support. Comments and bugreports are also welcome. Please refer to the project page at SourceForge: http://sourceforge.net/projects/groundstation
Happy Tracking!
Alexandru Csete
OZ9AEC