A computer includes a processor and a memory storing instructions executable by the processor to select a scanning rate for a first sensor of a vehicle based on at least one of data related to a current time or data related to a location of the vehicle; instruct the first sensor to run at the selected scanning rate; in response to receiving data from the first sensor indicating a newly present object, turn on a second sensor; and then record data from the second sensor. The second sensor has a higher power draw than the first sensor.