Abstract: Among other things, techniques are described for a universal calibration target. The universal calibration target includes a core and an outer body. The core is core associated with a first salient property. The outer body is associated with a second salient property. The first salient property and the second salient property are configured to be observed by a sensor modality, and the first salient property and the second salient property correspond to at least one sensor of a vehicle.

Abstract: Among other things, we describe a self-cleaning sensor housing. The self-cleaning sensor housing includes at least one sensor comprising a sensor aperture, a motor rotatable about a first axis of revolution, a substantially transparent screen rotatable about a second fixed axis of revolution, and a cleaning mechanism located proximate to the screen and configured to contact the substantially transparent screen. The screen is mechanically coupled to the motor and covers at least a portion of the sensor aperture. We also describe methods for performing self-cleaning operations.