I am just stumbling across the following problem: I want to find a set of points with a distance of at most 50 meters from a given query point. I know how to calculate both the Harvesine and the euclidean distance, that is not the problem.
However, I need to be able to find the closest point in logarithmic time. For this reason I am using an R-Tree. However, as far as I know R-Trees only work with euclidean distances. I am working in a relatively small area so I think the error is negligible.
However, here is the problem: In order to find the points within the given radius (wrt to the euclidean distance) I need to have an idea what multiple of (x_1 - x_2)^2 + (y_1 - y_2)^2 of GPS coordinates corresponds to 50 meters. I realize that this is not a well-posed question^^ I am interested for a value working for the Berlin area. Any ideas?
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However, I need to be able to find the closest point in logarithmic time. For this reason I am using an R-Tree. However, as far as I know R-Trees only work with euclidean distances. I am working in a relatively small area so I think the error is negligible.
However, here is the problem: In order to find the points within the given radius (wrt to the euclidean distance) I need to have an idea what multiple of (x_1 - x_2)^2 + (y_1 - y_2)^2 of GPS coordinates corresponds to 50 meters. I realize that this is not a well-posed question^^ I am interested for a value working for the Berlin area. Any ideas?
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