Understanding the Kalman filter with a simple radar example

96 points - today at 5:11 PM

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alex_be today at 5:13 PM
Author here.

I recently updated the homepage of my Kalman Filter tutorial with a new example based on a simple radar tracking problem. The goal was to make the Kalman Filter understandable to anyone with basic knowledge of statistics and linear algebra, without requiring advanced mathematics.

The example starts with a radar measuring the distance to a moving object and gradually builds intuition around noisy measurements, prediction using a motion model, and how the Kalman Filter combines both. I also tried to keep the math minimal while still showing where the equations come from.

I would really appreciate feedback on clarity. Which parts are intuitive? Which parts are confusing? Is the math level appropriate?

If you have used Kalman Filters in practice, I would also be interested to hear whether this explanation aligns with your intuition.

palata today at 7:13 PM
joshu today at 7:05 PM
i liked how https://www.bzarg.com/p/how-a-kalman-filter-works-in-picture... uses color visualization to explain
smokel today at 6:54 PM
This seems to be an ad for a fairly expensive book on a topic that is described in detail in many (free) resources.

See for example: https://rlabbe.github.io/Kalman-and-Bayesian-Filters-in-Pyth...

Is there something in this particular resource that makes it worth buying?

lelandbatey today at 7:29 PM
Kalman filters are very cool, but when applying them you've got to know that they're not magic. I struggled to apply Kalman Filters for a toy project about ten years ago, because the thing I didn't internalize is that Kalman filters excel at offsetting low-quality data by sampling at a higher rate. You can "retroactively" apply a Kalman filter to a dataset and see some improvement, but you'll only get amazing results if you sample your very-noisy data at a much higher rate than if you were sampling at a "good enough" rate. The higher your sample rate, the better your results will be. In that way, a Kalman filter is something you want to design around, not a "fix all" for data you already have.
unit149 today at 8:17 PM
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