For quite some time I’ve been maintaining an open source project for SGP4 and SDP4 orbit predictions, written in Java. This can be found at:
http://code.google.com/p/predict4java/
It’s a port of John Magliacane’s ‘C’ Predict program.
I’m now going to make these predictions available as a RESTful web service.
The initial services will be:
As a user, get the list of satellite available:
/services/satellites/list
As a user, get the real-time vectors for a specific satellite:
/services/satellites/vectors/[catalogNo]
As a user, get the vectors for a specific satellite for my location:
/services/satellites/vectors/[catalogNo]?lat=[FP decimal, +N, -S]&lon=[FP decimal, +E, -W]&amsl=[decimal]
As a user, get the prediction for a specific satellite:
/services/satellites/prediction/[catalogNo]?lat=[FP decimal, +N, -S]&lon=[FP decimal, +E, -W]&amsl=[decimal]&hrs[decimal]
To reduce system load:
- the vectors will be updated every 2 sec as this would be within the 3db points of a tracking antenna.
- tracking of a satellite will begin after the first service call and remain in effect for 10 minutes after the last call. A call within the 10 minute grace period will restart normal tracking.
