The present teaching relates to method and system for an assembly for protecting a sensor. The assembly includes a first structure having a rectangular prism and connected with a truncated tube, wherein the rectangular prism and the truncated tube have parallel longitudinal axes and the tube is truncated to yield a cross section having a norm that forms an angle with the longitudinal axis of the truncated tube and a second structure of a trapezoid prism having a longitudinal axis parallel to the longitudinal axes and with the first structure embedded therein. The second structure has a slanted surface in the front that meets the cross section of the truncated tube and has the norm of the cross section.