Abstract: A method includes maintaining a representation of a spatial region, maintaining a plurality of trajectory records, each trajectory record comprising a sequence of time points and corresponding spatial coordinates, maintaining, for each trajectory record of the plurality of trajectory records, sensor data, the sensor data being synchronized to the sequence of time points and corresponding spatial coordinates, presenting a portion of the representation of the spatial region including presenting a representation of multiple trajectory records of the plurality of trajectory records, each trajectory record of the multiple trajectory records having at least some spatial coordinates located in the portion of the spatial region.