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Are Unscented Extended Kalman filters (UEKF) preferred over Multiplicative Extended Kalman filters (MEKF) in satellite ADCS systems?

What are the trade-offs for these two filters?

I have read that UEKFs are better at estimating 2nd order noise effects because it samples the noise distribution which allows for faster convergence.

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There is no UEKF. There is UKF. Yes, it performs better than EKF/MEKF. And yes it's computationally expensive for that matter. And yes, people are looking into SPUKF/ESPUKF to reduce that computational overhead.

But again, follow the golden rules: "If it ain't broke, don't fix it". Typically these filters alone are an illogical point of metrics from a mission perspective. This whole sensor fusion thingy is coupled with hardware. Good hardware + shizzle software = functions, then viola! Shizzle hardware + awesome software = still doesn't work, then "insert hello darkness my old friend here". Random puns apart, there have been precision pointing mission in the past that got away with just a KF and PD, only the control bandwidth had to be pumped up to 4Hz from 2Hz.

It's very mission/hardware/satellite specific. Check out the classic paper: Survey of Nonlinear Attitude Estimation Methods from hotshots featuring: John L. Crassidis, F. Landis Markley and Yang Cheng. Blue Canyon Technology from what I understand runs a 6 state MEKF. If it works for them, it could easily work for a rigid body mission for you.

P.S. Sorry for the informal lingo, had too much caffeine today. Have a good day :)

Ad Astra.


Edit (in progress):

I realized there is indeed a UEKF. Never saw it applied on a sat mission before. Shall dig it, in free time, and come up with a rather constructive answer. This Paper claims that UEKF performs better than UKF, and has less computational time. Interesting. This is not a paper on ADCS, but target tracking instead. Different frameworks.

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  • $\begingroup$ I added some breaks for (potential) paragraphs and added a link for you. When the caffeine wears down a bit you might consider doing a bit of tidying up; I am not sure how many people can understand how this properly answers the question. Perhaps it does... I just can't tell. $\endgroup$ – uhoh Apr 8 at 13:18
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    $\begingroup$ Thanks for the paragraphs and links :) Also, I realized there is indeed a UEKF. Never saw it applied on a sat mission before. Shall dig it, in free time, and come up with a rather constructive answer. This Paper claims that UEKF performs better than UKF, and has less computational time. Interesting. This is not a paper on ADCS, but target tracking instead. Different frameworks. $\endgroup$ – Watch This Apr 8 at 14:07

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