METHODS AND MEANS FOR UTILIZING APODIZED BEAMS

摘要

Apodized beams of electromagnetic radiation are used in a transmissometer and earth motion detector. A laser beam (11) which is apodized by a conical scanning means is transmitted from a device (14) to a remote point (20) where it is retroreflected to the device to provide measurements relating to the transmissivity of the physical environment. In a different application the conically scanned apodized laser beam (11) is directed to a retroreflector (22) which is then returned to the transmitting point. Relative movement between the transmitting point and the remote point are detected by the change in beam position with respect to the retroreflector (22). With several transmitters and receivers orientated at different propagation angles different relative movement parameters are obtained. The conically scanned laser beam has a substantially Gaussian intensity profile, but alternative symmetrical profiles of other electromagnetic radiation can be used.