# Grid and Monte Carlo

We will describe two localization algorithms that are capable of solving global localization problems.

* They can process raw sensor measurements. There is no need to extract features from sensor values.
* They are non-parametric.
* They can solve global localization and kidnapped robot problems.

The first approach is called *grid localization*. It uses a histogram filter to represent the posterior belief.  The second approach is called the *Monte Carlo localization*, arguably the most popular localization algorithm to date. It uses particle filters to estimate posteriors over robot poses.&#x20;


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