This disclosure relates to systems and techniques for identifying collisions, such as relatively low energy impact collisions involving an autonomous vehicle. Sensor data from a first sensor modality in a first array may be used to determine a first estimated location of impact and second sensor data from a second sensor modality in a second array may be used to determine a second estimated location of impact. A low energy impact event may be configured when the first estimated location of impact corresponds to the second estimated location of impact.