Abstract: A method of measuring the surface temperature of an object. The method includes performing ellipsometric measurements on the object in order to determine at least first and second photon energies (E.sub.1, E.sub.2) for an electromagnetic beam at which measurements are respectively substantially independent of temperature and dependent on temperature. The method further includes creating and directing to the object, an electromagnetic incident beam including at least the first and second photon energies (E.sub.1, E.sub.2). The change in polarization at the first photon energy (E.sub.1) is measured and the thickness of the layer of material is determined on the basis of this measurement. The surface temperature of the object can then be determined on the basis of the measured change in polarization at the second photon energy (E.sub.2) of the beam, while taking account of the thickness of the layer of material.

Abstract: An array with high resolving power and low secondary lobe levels, comprising a receiving array formed of transducers along its length L.sub.R, two of these transducers, separated by a distance L.sub.E, also forming the transmitters. The change from transmission to reception and back is effectuated by switches. Signals received by transducers are weighted by resistors before being delivered to beam forming circuits, containing multi-terminal phase shifters and a wiring matrix and adders. The weighting function and ratio L.sub.E /L.sub.R are chosen to ensure that the overall transmission-reception system diagram has high resolving power and low secondary lobe levels.