Peter Parker aka Spiderman, once said, "With great power comes great responsibility". While we don't have Parker's r'sum?, he may have temporarily worked as a telemetry technician before opting for a relatively relaxed profession of freelance photography. To understand the responsibilities of a telemetry technician, one needs to understand telemetry first. Telemetry or "remote measurement" is a highly automated communications process by which measurements are made and other data collected at remote, inaccessible or dangerous places, such as orbiting satellites, and then relayed to receiving stations on ground for display, monitoring, and recording. The telemetry technician has many different job responsibilites.
The telemetry technician has a wide variety of career opportunities which may include monitoring of large, complex systems such as chemical plants, oilrigs, satellites, electric power plants, gathering meteorological data, remote meter reading, logistics management, tracking endangered land and marine species, real time physiological monitoring of patients, and monitoring manned and unmanned space flights. If you are a telemetry technician charged with the maintenance of a telemetry service of any type, it is suggested that before your accept the contract, you or the owner of the equipment take possession of a service manual for that particular system. Essential information required for any effective servicing work includes the following:
- Assigned carrier frequency for the system
- Type of modulation, bandwidth (deviation), and maximum data rate
- Level and frequency of all pilot tones and sub-carriers
- Significance of each frequency in the modulation bandwidth
- Expected signals at input and output test points for each sub-section
- Sense of logic, baud rate of data and error correction scheme
If the source of the data is a remote station, which forms an integral unit with the radio equipment, you will also need information on the type and location of the sensor supplying the original information and details of any preliminary data processing that may be done before the input to the radio link. The telemetry technician in command of this great technology should monitor it conscientiously. For instance, for many environmental monitoring duties, such as stream gauging or automatic weather stations, the measurement values are unlikely to change significantly for many hours at a time. In such cases, it would be grossly uneconomical in terms of both electrical power and use of spectrum space to run the telemetry transmitter continuously. This is why telemtry transmitters are not often run continuously. Telemetry transmitters will continue to evolve and improve over time.
