StarBridge v 0.6.0 now supports a GUI for easier use. In this release, the GUI is really only usable for specifying the satellites you want to monitor, and for converting satellite information from one format to another.
Introduction
System Requirements
Downloading StarBridge
Installation
Usage
Folder Information
Celestia User Information
Known Issues
Version History
StarBridge is a utility that can convert (read: bridge) data formats between astronomical catalogs and applications. I developed this program initially to allow me to create my own stellar catalog in XML format and then import that information into Celestia, a great " space viewing" program. Celestia uses stellar information from the Hipparcos survey. However, I wanted the ability to be able to update the information used by Celestia quickly and easily.
I have also had requests to be able to quickly update the Celestia information with more recent satellite information. It turns out that the orbits of satellites are constantly being affected by a variety of things, atmospheric drag, dockings with the international space station, etc. As a result, satellite information is updated on a daily basis. StarBridge can now quickly update earth orbiting satellite information.
Furthermore, I see that many Celstia users are interested in creating their own universes and then viewing them in Celestia. There are many people that create great addons that show Star Trek and Star Wars types of vehicles and they want the ability to easily create appropriate galaxies to house those spacecraft. StarBridge makes that much easier to do because it allows a designer to create star systems using XML notation instead of creating binary files. You can create a fictional universe using XML and then simply have StarBridge convert that XML universe into the stars.dat binary file used by Celestia.
StarBridge requires Java 1.5 or later to be installed on your machine. You may also want to download the Hipparcos catalogs from the following locations:
Store the two files in the StarBridge/catalogs folder for easy reference. This is the default location for all catalogs.
Currently you can download StarBridge directly from my web site. If you are interested in the source code you can download that also.
Installation is simple. Create a folder named StarBridge> on your local hard drive and unZIP the ZIP file that you downloaded into that StarBridge folder. If you are using Linux or Unix, you should create this folder somewhere in your home directory to be sure that you have the rights to create the folder and manage files within that folder. If you are a Windows user you don't need to worry about the location of your StarBridge folder.
There are a couple of simple steps that you will want to perform after you install StarBridge. The first is to create an environment variable named STARBRIDGE_HOME and point it to the directory where you unzipped StarBridge. For example, if you unzipped StarBridge into a directory named C:\StarBridge, then you need to set the STARBRIDGE_HOME variable to C:\StarBridge. Please refer to your operating system instruction manual for how to create an evironment variable for your system.
If you are a Celestia User, you will want to copy the starbridge.celx file from the Celestia/ folder (in the StarBridge home directory) and paste that script into the scripts/ directory of your Celestia installation. This will allow you to access the script within Celestia by selecting File -> Scripts -> starbridge.celx from the Celestia main menu.
If you intend to use StarBridge frequently, I suggest adding the StarBridge bin/ folder to your PATH environment variable so you can quickly and easily access the scripts there.
The easiest way to use starbridge is by running one of the pre-built scripts in the bin/ directory. Here is a description of the various scripts and what they do:
| Script | Description |
|---|---|
| starbridge[.cmd] | This is the recommended way to start StarBridge. This script will invoke the StarBridge application in GUI mode. This mode will allow you to easily select the satellites that you wish to monitor. |
| HIP2Celestia[.cmd] | This script will convert the Hipparcos survey data in the hip_main.dat and
hip2.dat files in the catalogs/ folder into a stars.dat file (also in the catalogs/ folder)
that Celestia can use.
NOTE:You must first download the Hipparcos survey data and store it in the catalogs/ directory. You can download the hip_main.dat file by clicking on this link: hip_main.dat You can download the hip2.dat file by clicking on this link: hip2.dat. The stars.dat file must be copied from the catalogs/ directory into the data/ directory of your Celestia installation before you run Celestia. I recommend making a backup copy of the original Celestia stars.dat file so that you can go back to the original when you wish. |
| HIP2StarBridge[.cmd] | This script will convert the Hipparcos survey data in the hip_main.dat and
hip2.dat files in the catalogs/ folder into a StarBridge formatted universe file named hipparcos.xml
(also in the catalogs/ folder). This is the native format that StarBridge uses to represent a universe.
A StarBridge universe is a collection of star system information.
NOTE:You must first download the Hipparcos survey data and store it in the catalogs/ directory. You can download the hip_main.dat file by clicking on this link: hip_main.dat You can download the hip2.dat file by clicking on this link: hip2.dat. You can safely leave the hipparcos.xml file in the catalogs/ directory so that you can use it in the future. |
| Sample2Celestia[.cmd] | This script will convert the catalogs/SampleUniverse.xml file into a Celestia formatted stars.dat file
(also in the catalogs folder). This script shows how you can create you own universe by taking a StarBirdge
formatted universe file (the SampleUnivers.xml file in this case) and generate a Celestia stars.dat file.
The stars.dat file must be copied from the catalogs/ directory into the data/ directory of your Celestia installation before you run Celestia. I recommend making a backup copy of the original Celestia stars.dat file so that you can go back to the original when you wish. |
| showHelp[.cmd] | This script will tell the StarBridge application to show its help text only. StarBridge will close after the help text is displayed. |
| UpdateCelestiaSatellites[.cmd] | This script will tell the StarBridge application to retrieve all of the satellite information
from NORAD (hosted by the CelesTrak.com web site) and write that information into the
catalogs/ directory using the filename norad_satellites.xml If you then copy this file into the extras/ directory in Celestia, you will be able to see all of the satellites when you right-click on the Earth and select Satellites -> Spacecraft from the popup menu in Celestia. Alternatively, if you follow the steps given in the Post Installation Steps section of this document, you will see how to add a Celestia CELX script to Celestia to make this update process much easier. If you take a look at the data/celestrak.properties file, at the bottom is where you can customize which satellites, or groups of satellites, you want to track. Norad tracks 1160 satellites as of December 28th, 2008, so you probably don't want to load all of those into Celestia. For details on customizing the data/CelesTrak.properties file, check out Customizing the CelesTrak Properties File |
You can always access the built-in help information for StarBridge by placing -help or -?
as the first and only argument when starting StarBridge. For example:
java -jar starbridge.jar -help
StarBridge deals with large quantities of information. As a result, the default Java heap space is usually insufficient and you need to pass in some parameters that give the Java virtual machine more memory to work with. Below is an example of a command that will give Java more memory while instructing StarBridge to read the Hipparcos data files and write out a Celestia stars.dat file.
java -Xms64m -Xmx1024m -jar ../starbridge.jar -readUniv HipparcosAdapter hip=..\catalogs\hip_main.dat hip2=..\catalogs\hip2.dat -writeUniv CelestiaAdapter data=..\catalogs\stars.dat names=..\catalogs\starnames.dat
However, passing in these arguments is a bit tedious, so I have also included several Windows scripts (found in the bin/ folder) that take care of these details for you. I recommend that you write you own scripts or use the ones that I have provided until I get a proper GUI in place. The command line that I list above is the same one that I use in the bin/HIP2Celestia.cmd script.
There are a number of folders in StarBridge. Here is a quick overview of their purposes.
StarBridge contains an addon for the Celestia application. If run StarBridge in GUI mode you can install the add-in by selecting Tools -> Install Celestia Addon from the StarBridge main menu. This will do several things:
| Model | Author | Notes |
|---|---|---|
| goes.3ds | Jeff Davies | This is the default mesh used for all GOES satelllites. Its very crude and is screaming for a better model and some textures (hint, hint). |
| satellite.3ds | Jeff Davies | This is the default mesh used for all satelllites that do not have a specific mesh. It also needs a better model and some textures. |
There are a number of issues that I am aware of and currently investigating or fixing
.sbuniv instead of
.xml. Similarly, satellite files end with .sbsat instead of .xml.data/ directory to config/ to more accurately reflect its purpose.Select Satellite By Name field in the Select Satellites
dialog box. For example, if you enter the following: ^ISS, [.]*DEB[.]* into the By Name
field of the Select Satellites dialog, you are telling StarBridge to look for all satellites whose name
either starts with ISS or contains the string DEB. These are examples of
"Regular Expressions". They can be a bit tricky to use and they are not for the faint of heart. To
learn more about regular expressions just Google it!PATH environment variable and have access to the StarBridge command at all times.Copyright © 2009 Jeff Davies. All Rights Reserved.