Macintosh Software For Satellite Tracking Applications

As a dedicated Macintosh user, I wanted to run software to help me illustrate what satellites were doing. But finding software for the Mac was extremely difficult. After many hours of effort, and sadly getting very little help from other Mac users, I have compiled these pages to help. Of course there are web pages that allow you to track satellites as well but I have not included them. Maybe some day. Having software on your computer gives you some flexibility that a web page could not provide. 

After hacking around for months, it turns out that there is a lot that we can do on the Mac.  

One big need I have is to visualize where satellites are in relation to each other and the ground below them, to generate “ground traces” on a map. This also helps me illustrate the relationship between satellites in space, more about that later. There are two programs that I have found that do this - Gpredict and JSatTrak. Another need I have is to help others track some satellites, and Gpredict and JSatTrak help me predict acquisition times and angles. Then I can suggest to others where and when to look - more about this in later pages on this site. 

This is an example from Gpredict of what we can do, display ground traces of satellites. 

Gpredict is a ported Unix (written for Linux) application, and you have to use a site and command to install it on your Mac. One site is MacPorts, and it works with a software repository of “ported” Unix applications that have been written to run on Macintosh. They retain that blocky Unix look and feel, but they run well. MacPorts seems to be unreliable at times and so I am going to try to install with "Homebrew" which is a comparable installer for ported applications. 

Homebrew software installer

I only use a little of what Gpredict does but it has really helped me. Now a partner and I are starting to use the program to actually track satellites. 

If you are interested in how to do this, check out this page: Tracking Satellites With Telescopes

JSatTrak is a Java application that you can just install as if it was a native Mac application. It also does not have that polished Macintosh look, it is clunky (out of the box), but it does run. JSatTrak generates ground traces and also does a lot more. I have not yet learned how to do many of the things that JSatTrak promises but I hope to get around to learning more about it. 

The links to the pages to get these applications are on the next page.

There is another big application, the General Mission Analysis Tool (GMAT) that has been written by people at the Goddard Space Flight Center, and I have seen it running on Macintosh. They had instructions for installation but they were flawed, I spent many hours trying to install GMAT and just did not have the right information. I hope to get back to it sometime. 

For those out there that speak French, there is a promising application written by Micael Germann of Lausanne, Switzerland called SatObserver. It is also in English. I am working through that as well and will add it as it matures. At this writing it is at Version 0.6.2 - it is linked from other sites (see later pages). If you don't mind a lot of trial and error, and know how some of the other programs work, you could get it and peck at it for a while, it has some good features.

At least Gpredict still runs on my beloved iBook G4. A caveat about my assumptions about the reader. I am going through these pages as if the reader has a fairly current computer, and will hope to add more detail later for those with older systems. But I first installed and ran Gpredict acceptably on a Powerbook with a G3 chip. 

And I run some C code as well - one application was written by Tim DeBenedictis of Southern Stars - hopefully with time and permission I may make it available?? I also run some parts of C code that David Vallado has made available - though I have updated it and had two other (far more talented) programmers help me with it. David has a lot of C code available (and Pascal, etc) but it is NOT trivial to try to get it to run. 

I have begun to write some C and C++ code as well - to do things like find apogee and perigee from a TLE. You can do this from Excel (which is how I have always done it) but it was fun to write this small tool - and you just put the TLE in the same folder and run the program. If anyone is interested let me know - it is not quite ready for distribution yet but it's priority could go up. It turns out that (once you put the pieces together!) you can write C and C++ applications - and run them from the desktop - fairly quickly. You do need to understand: how to do a few tasks under Unix, how to write some code, and how to get the files where you can find them. 

I have certain things that I need and the applications do a lot of that for me - there is certainly a LOT that they do that I have not ever explored. If they do something neat and you tell me about it, I will add it here so others can see. 

As of: 28 Jan 2019

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