This disclosure describes techniques to count objects in an area. The techniques include operations comprising: receiving, from a first sensor, data that identifies a location of a first object in an area at a given point in time; receiving, from a second sensor, data that identifies a location of a second object in the area at the given point in time; and aggregating the data from the first sensor and the data from the second sensor to compute a count value indicating how many objects are present in the area at the given point in time.