Highly automated communications process by which data are collected from instruments located at remote or inaccessible points and transmitted to receiving equipment for measurement, monitoring, display, and recording. Transmission of the information may be over wires or, more commonly, by radio. The technique is used extensively for oil-pipeline monitoring and control systems and in oceanography and meteorology. Telemetry for rockets and satellites bloomed in the 1950s and has continued to grow in complexity and in breadth of application. Data can be transmitted from inside internal-combustion engines during tests, from steam turbines in operation, and from manned and unmanned spacecraft. Major scientific applications include biomedical research and remote observation of operations with highly radioactive material.