Objects as small as 30cm
Is 30cm the resolution limit, the pixel size or the size of an arbitrary object that can be recognised in the image?
Resolution limit means the ability to resolve a pair of high contrast lines not less than that wide, pixel size is typically a quarter to a ninth of the area of the minimum resolvable dot. Neither mean that objects of this size could be recognised from the images. I would guess that the size of a minimum recognisable object is more likely to be in the order of 1.5-3 meters.