Color dots are displayed to show the signal readings that are detected as the user walks around. Each dot is colored according to the strength of the signal and the selected color map. Gray dots are displayed when the user has walked in that area, but there is no signal detected.
The color dots can be displayed in two modes, either as actual readings or with interpolation. Interpolated dots appear smaller and have a gray border. It is typical for the color dots to move slightly as the user walks around. This is due to back propagation, where the navigation algorithms use constraint information such as check-ins to improve the accuracy of the path in the past.