A drain grate system can be installed in a curbside or storm drain to block the passage of debris while allowing liquid to flow into the drain. The invention improves the acquisition of measurement data in a mattress having sensors arranged in the region of the thorax and or sacrum by using a measurement method in which measured values from the sensors are measured and recorded continuously. Within the unified system, parallel processing computer systems, each having an input controlling a plurality of computers, generate and output user information at receiver stations. Certain types of fiber optic connectors have the storage device mounted in a cavity defined in the fiber optic connector. Using the stored ray maps, the seismic data are migrated into seismic image volumes, each volume being characterized by at least an azimuthal angle bin, the azimuthal angles being computed from said ray dip angle information.