The AstroStat Slog » Kalman filter http://hea-www.harvard.edu/AstroStat/slog Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders Fri, 09 Sep 2011 17:05:33 +0000 en-US hourly 1 http://wordpress.org/?v=3.4 [MADS] Kalman Filter http://hea-www.harvard.edu/AstroStat/slog/2009/mads-kalman-filter/ http://hea-www.harvard.edu/AstroStat/slog/2009/mads-kalman-filter/#comments Fri, 02 Oct 2009 03:18:32 +0000 hlee http://hea-www.harvard.edu/AstroStat/slog/?p=1397 I decide to discuss Kalman Filter a while ago for the slog after finding out that this popular methodology is rather underrepresented in astronomy. However, it is not completely missing from ADS. I see that the fulltext search and all bibliographic source search shows more results. Their use of Kalman filter, though, looked similar to the usage of “genetic algorithms” or “Bayes theorem.” Probably, the broad notion of Kalman filter makes it difficult my finding Kalman Filter applications by its name in astronomy since often wheels are reinvented (algorithms under different names have the same objective).

When I learned “Kalman filter” for the first time, I was not sure how to distinguish it from “Yule-Walker equation” (time series), “Pade approximant, (unfortunately, the wiki page does not have its matrix form). Wiener Filter” (signal processing), etc. Here are those publications, specifically mentioned the name Kalman filter in their abstracts found from ADS.

The motivation of introducing Kalman filter although it is a very well known term is the recent Fisher Lecture given by Noel Cressie at the JSM 2009. He is the leading expert in spatial statistics. He is the author of a very famous book in Spatial Statistics. During his presentation, he described challenges from satellite data and how Kalman filter accelerated computing a gigantic covariance matrix in kriging. Satellite data of meteorology and geosciences may not exactly match with astronomical satellite data but from statistical modeling perspective, the challenges are similar. Namely, massive data, streaming data, multi dimensional, temporal, missing observations in certain areas, different exposure time, estimation and prediction, interpolation and extrapoloation, large image size, and so on. It’s not just focusing denoising/cleaning images. Statisticians want to find the driving force of certain features by modeling and to perform statistical inference. (They do not mind parametrization of interesting metric/measure/quantity for modeling or they approach the problem in a nonparametric fashion). I understood the use of Kalman filter for a fast solution to inverse problems for inference.

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[Quote] Abstract – There are none. http://hea-www.harvard.edu/AstroStat/slog/2008/quote-abstract-there-are-none/ http://hea-www.harvard.edu/AstroStat/slog/2008/quote-abstract-there-are-none/#comments Fri, 11 Jan 2008 01:57:23 +0000 hlee http://hea-www.harvard.edu/AstroStat/slog/2008/quote-abstract-there-are-none/ From Guaranteed Margins for LQG Regulartors J.C. Doyle (1978) IEEE Transactions on Automatic Control 23(4), pp. 756- 757

The abstract has one sentence: There are none and the first paragraph of this short paper explains the uniqueness of the abstract:

Considerable attention has been given lately to the issue of robustness of linear-quadratic (LQ) regulators. The recent work by Safonov and Athans[1] has extended to the multivariable case the now well-known guarantee of 60(deg) phase and 6dB gain margin for such controllers. However, for even the single-input, single-output case there has remained the question of whether there exist any guaranteed margins for the full LQG (Kalman filter in the loop) regulator. By counterexample, this note answers that question; there are none.

Quoting the whole abstract is an intention of little entertainment, whereas the content may not be of any interests to astronomers and statisticians. There is a long winding evolutionary history in Automatic Control, which has dragged many mathematicians, applied mathematicians, and statisticians (The earlier versions of Kalman filter, AIC, and MDL appeared in this journal).

  1. M.G. Safonov and M. Athans (1977), IEEE Transactions on Automatic Control, 22 (Apr.), pp. 173-179
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