In one aspect of the present invention, a filter is provided including a first layer of sheet material having a first base portion, and a plurality of first raised portions extending from the first base portion and defining a corresponding plurality of first openings through the first layer. The echo cancellation circuit includes a gain calculator, a gain adjustment circuit, and a subtraction circuit. The reading unit is configured to read the sheet at a reading position. A method for augmenting reality generally comprising the steps of disposing a pattern of fiducials on an object surface, tracking the position and orientation of the object, retrieving and processing virtual information stored in a computer memory according to the position and orientation of the object and presenting the virtual information with real information to a user in near real time. These bands may decrease drag, or may increase lift.