haisam.ido@gmail.com a écrit :
This may be of interest to others. I've added my crude Space Flight Dynamics as a Service (SFDaaS) application on GitHub here https://github.com/haisam/SFDaaS .
Thank you very much Haisam, this is interesting. I have two questions about this project.The first question is a legal one. Are people allowed to use this code, change it and publish it ? I did not find any copyright nor licensing terms. Orekit by itself is Apache licensed, to allow almost any use, but without any hint about the licensing scheme, we do not know even if we can simply use your project locally, notwithstanding modifying or republish it.
The second question is a technical one. One of the current problem in Orekit is thread-safety (see issue <https://www.orekit.org/forge/issues/3>. The reason this problem is not solved yet is due to data caching needs, which implies that simply adding a bunch of "synchronized" statements does NOT work (see <https://www.orekit.org/forge/projects/orekit/wiki/SOCIS#secure-multi-threading-in-Orekit-while-preserving-data-caching-features>). This is a major problem and it typically appears in web services. Thomas addressed the problems of Frames, but there are more problems like this one in the library. Did you experience any concurrency problems ? Do you have some ideas about how to solve it ?
best regards, Luc
Currently, its only capability is to propagate state forwards or backwards in time using the http://orekit.org Java library. Requirements: * Eclipse IDE * Tomcat 6.0 * apache.commons.math (included) Usage: http://localhost:8080/SFDaaS/PropagateServlets?t0=2010-05-28T12:00:00.000&tf=2010-05-29T12:00:00.000&r0=[3198022.67,2901879.73,5142928.95]&v0=[-6129.640631,4489.647187,1284.511245] Output: ------------------------------------------------------------------------------------- Run Start : 2011-10-07T23:48:48.894-0400 Run End : 2011-10-07T23:48:48.907-0400 A priori state : Epoch = 2010-05-28T12:00:00.000 r = [3198022.67,2901879.73,5142928.95] v = [-6129.640631,4489.647187,1284.511245] Posteriori state : Epoch = 2010-05-29T12:00:00.000 r = [5630517.796159,-3606350.100536,-606046.049292627] v = [3048.698685,3756.457104,6000.256417807639] The epochs are assumed to be UTC and r0 and v0 are in meters and in the J2000 Earth-centered frame. -------------------------------------------------------------------------------------
---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.