Abstract: A multi-layer flexible sheet is provided for hanging freely on the interior room side of a window, or the like, that reflects radiant heat from inside the room back into the room with high effective reflectivity, transmits light from the window into the room adequately for looking out, is easily rolled up when not needed, and, furthermore, can be used in summer to reflect out undesired heat and glare from incident sunlight without undue loss of transparency for looking out. A synthetic resin layer of polyethylene or polypropylene having a thickness not exceeding 0.1 mm is on the room side of the laminate and has a metallic film on its outward-facing surface of gold or aluminum that does not need to be of high uniformity in thickness. A cover layer of transparent synthetic resin on the side facing the window protects the metallic film from mechanical damage and is of strength and thickness sufficient to supply any additional necessary mechanical stability.

Abstract: A plurality of sensors are located on one of the bodies, staggered by fixed distances from each other along the direction of relative movement. The sensors are responsive to a characteristic of the other body, for example to surface characteristics of a roadway. A sensed signal, picked up by a first, or leading sensor is time delayed for a predetermined time interval, and compared with signals received from all the other sensors. Upon optimum correlation, and with known time delay and distance between sensors, the relative speed can then be indicated by determining which one of the sensors picked up the signals which matched the time delay signal. The amplitudes of the signals can be dynamically equalized and the time delay itself changed to permit output over wide ranges, or with respect to different scaling units.