Want to learn using OREKIT

I am new to all the Astro Physics and OREKIT. I am CS major, my company uses OREKIT, but there is no real knowledge share as the people who developed left.
I want to learn, where to start?

Hi @mallinarc

Welcome to the Orekit community! We are always happy to see new Orekit users :slightly_smiling_face:

There are several places to learn about Orekit. The first one is the forum. Indeed, a lot of questions were asked on the forum and the answers can help you to understand Orekit library. If you want to learn more about one specific functionality of Orekit, you can search the related discussions on the forum using the research functionality on the top right of the forum.

After that, I can recommend you to look at the Maven site. It is a very interesting place to learn more about Orekit architecture and functionalities. You will also find information about downloading and installing Orekit.

I also recommend you to look at our tutorials. We have developed a lot of Java tutorials to help Orekit users understanding the main functionalities of the library (i.e., orbit propagation, frame and time transformation, maneuvers, orbit determination, etc.). A Gitlab repository is available to download the Java tutorials. The tutorials can be executed using your favorite IDE, like Eclipse.

A particular attention is paid to the Javadoc. All the Orekit classes and methods have a JavaDoc. We try to write the JavaDoc as clear as possible, with details and use cases to let the users understand the corresponding functionality. So, when using Orekit of the first time, I always recommend to have the API JavaDoc opened somewhere :slightly_smiling_face:
Please note that you can find the JavaDoc for all Orekit versions on the website.

Best regards,

Hi Bryan,

Thanks for your reply.

I am wondering, with my Java background I want to learn Orekit. I want to build some test scenarios so I can understand what components of Orekit do. Also wondering if there is a visual ( UI ) piece to see how the satellite and Ground object are located at each time interval?

My only reason for that is with no astro physics background the more visual the better to understand.

If your objective is to build scenarios using Orekit, I strongly recommend you to look and try our tutorials (the link is in my previous post).

There is no UI with Orekit. The main reason is that we want Orekit to have as few dependencies as possible so that it can be integrated easily into as many systems as possible. Indeed, having an UI would impose on users an additional dependency: the Orekit UI. However, many users only want access to Orekit’s code without embedding the UI that would go with it. In addition, other users already have their own UI and offering one would make Orekit difficult to integrate into their system. For all these reasons, Orekit is a code-only library with just 2 dependencies: Hipparchus for its mathematical needs and JUnit for the validation.



I am new as well, looking into learning Orekit. Thanks for everyone’s support.

The tutorials seem a bit outdated, has anyone tried running them on 10.3.1? – setMasterMode, setSlaveMode was removed from the propagator interface and I don’t know what to use in its place. AttitudesSequence.addSwitchingCondition had its parameters re-arranged, and there may be a couple other minor things.

Would you recommend I raise an issue for these? – and/or recommend a fix?

Thank you for your help.

edit – ah added class/interfaces instead of callbacks… More Java oopy, I like it.

Hi @Evan

Welcome to the Orekit forum! :slightly_smiling_face:

In this case, this is your Orekit version which is outdated compared to the version of the tutorials you are using. I guess you are using the development version of the tutorials, which needs a 11.0-SNAPSHOT version of Orekit (i.e., Orekit development version). To run properly the tutorial with the last official Orekit version (i.e., 10.3.1) you must also use the last official version of the tutorial (i.e., 10.3). It corresponds to the master branch available on the GitLab repository of the Orekit tutorials.

Best regards,