Abstract: The disclosed technology provides solutions for confirming a sensor cleaning event of a sensor mounted on an autonomous vehicle. A method of the disclosed technology can include steps for receiving a first plurality of image frames from an optical sensor; segmenting each of the first plurality of image frames into one or more interest regions; computing image statistics for each of the one or more interest regions; generating an image mask based on the image statistics for each of the one or more interest regions; receiving a second plurality of image frames from the optical sensor; applying the image mask to the second plurality of image frames; computing image statistics for each of the second plurality of image frames; and determining a status of a sensor cleaning event based on the image statistics for each of the second plurality of image frames. Systems and machine-readable media are also provided.