MojoDonkey
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Long time orbiter user - first post.
I'm working on a series of modules to build a "faux-IMU". Idea is to sample the actual vessel position per update cycle, and apply a little bit of jitter and drift in the gyros, and jitter, offset, deadband etc as well on the accelerometer side. 6 DOF - 3 gyro, 3 accel, and then to use this information to provide internal vessel state rather than the omniscient state feedback available from the APIs.
Planning on integrating an apollo style star sighting approach to re-align IMU state as required (will be "cheated" at first with a button).
Question is - what are vaguely real-tech ways to determine orbital parameters?
In the real world, ground based radar and computational feedback seems to be a very vital bit of this feedback. Assuming this was not available - what do you have?
Starting with launch - known position on surface. Known delta V and position integration (drift/noise error terms creeping up). Achieve orbit - how do you know? You could know your velocity (to a point) - but would not implicitly know your orbital parameters (unless error terms were small enough I suppose). Taking the known launch position out of the mix - say we wake up and just find ourselves orbiting the moon with no knowledge about your current state.
Do these thoughts sound remotely correct? :
If we throw a radar altimeter into the mix we could conceivably write a routine to measure altitude as we orbit (hopefully orbit), auto-correlate the min and max to determine orbital period, eccentricity, peri/apoapsis, velocity.
We would also have our star-fix re-aligned IMU to provide orientation. With that data we could also use an orbital model to determine the appropriate matrix for pro and retrograde positions.
Still in the dark with regard to inclination and longitude of ascending node though... would there be any method short of observation to determine these parameters?
Are there real world methods that would be of use here? Eager to hear.
Or maybe just add a fictional ground tracking station...
I'm working on a series of modules to build a "faux-IMU". Idea is to sample the actual vessel position per update cycle, and apply a little bit of jitter and drift in the gyros, and jitter, offset, deadband etc as well on the accelerometer side. 6 DOF - 3 gyro, 3 accel, and then to use this information to provide internal vessel state rather than the omniscient state feedback available from the APIs.
Planning on integrating an apollo style star sighting approach to re-align IMU state as required (will be "cheated" at first with a button).
Question is - what are vaguely real-tech ways to determine orbital parameters?
In the real world, ground based radar and computational feedback seems to be a very vital bit of this feedback. Assuming this was not available - what do you have?
Starting with launch - known position on surface. Known delta V and position integration (drift/noise error terms creeping up). Achieve orbit - how do you know? You could know your velocity (to a point) - but would not implicitly know your orbital parameters (unless error terms were small enough I suppose). Taking the known launch position out of the mix - say we wake up and just find ourselves orbiting the moon with no knowledge about your current state.
Do these thoughts sound remotely correct? :
If we throw a radar altimeter into the mix we could conceivably write a routine to measure altitude as we orbit (hopefully orbit), auto-correlate the min and max to determine orbital period, eccentricity, peri/apoapsis, velocity.
We would also have our star-fix re-aligned IMU to provide orientation. With that data we could also use an orbital model to determine the appropriate matrix for pro and retrograde positions.
Still in the dark with regard to inclination and longitude of ascending node though... would there be any method short of observation to determine these parameters?
Are there real world methods that would be of use here? Eager to hear.
Or maybe just add a fictional ground tracking station...
