Telemetry

What is Telemetry? Telemetry is a technology that allows remote measurement and reporting of information. The word is derived from Greek roots tele = remote, and metron = measure. Systems that need external instructions and data to operate require the counterpart of telemetry called telecommand. Although the term commonly refers to wireless data transfer mechanisms (e.g. using radio or infrared systems), it also encompasses data transferred over other media, such as a telephone or computer network, optical link or other wired communications. Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data.

Why Telemetry? Telemetry lets you stay in a safe (or convenient) location while monitoring what's taking place in an unsafe (or inconvenient) location. For Example, In aircraft development. For Industrial applications, Telemetry saves time, reduces overheads, improves customer satisfaction, provides additional selling features and in many applications has a rapid payback. Telemetry is used with satellites, space probes, and mobile robots. Telemetry is employed in manned spacecraft, such as the Space Shuttle and the International Space Station (ISS), to monitor the physical condition of astronauts and to ensure the maintenance of a proper working environment for them.

General Telemetry System A telemetry transmitter consists of a set of measuring instruments, an encoder that translates instrument readings into analog or digital signals, a modulator, and a wireless transmitter with an antenna. In today's telemetry applications, which support large numbers of measurands, it is too costly and impractical to use separate transmission channels for each measured quantity. The telemetry process also involves grouping measurements (such as pressure, speed, and temperature) into a format that can be transmitted as a single data stream.

General Telemetry System Once received, the data stream is separated into the original measurement’s components for analysis. A telemetry receiver consists of an antenna, a set of radio-frequency ( RF ) amplifiers, a demodulator, and recording devices. A computer can be used to process and store received information.

General Telemetry System

Important Consideration In Designing Telemetry Narrowband FM or Spread Spectrum: Until recently, narrowband FM was the dominant choice for wireless telemetry. A licensed, coordinated frequency was applied for and received assuring any additional future users would be responsible to avoid interfering. Now, spread spectrum is a popular choice where licensed narrowband frequencies are not available. No license to apply for, simply purchase equipment that is compliant with the FCC part 15 rules.

Important Consideration In Designing Telemetry Risk of Interference: Narrowband is a licensed frequency coordinated to give you a channel free from interference. Spread Spectrum is unlicensed using frequency hopping technology to avoid interference. In highly populated areas interference may be a problem while narrowband frequencies are shared frequencies, the rules state that any new users must take measures to avoid interference to all existing users on that frequency.

Important Consideration In Designing Telemetry Installation: Proper installation can mean the difference between a marginal telemetry system and a reliable one. Beyond the requirement for a reliable power source and protection from the elements, proper installation requires attention to grounding and lightning protection. Proper grounding guards against unwanted noise entering your system and will help prevent loss to communications equipment in the event of a lightning strike. Lightning protection can prevent a catastrophic failure just when you need your telemetry system communications the most to warn about a power failure at a mission critical site.

Applications: Flight Tests Flight test programs typically telemeter data collected from on-board flight test instrumentation over a PCM/RF link. data is analyzed in real-time for safety reasons and to provide feedback to the test pilot. Vibrations Velocities Flows Pressures Temperatures Particular challenges for Telemetering this data includes fading, multipath propagation and the Doppler effect If it is ORANGE it is flight test measurement

Applications: Cardiac Monitoring Outpatient cardiac telemetry is an option in some hospitals, with patients wearing monitors outside the hospital, and it is not necessary for them to be admitted in the hospital long time. In case of any serious disturbance such as heart attack or any critical organ failure, an alarm could be generated which could alert the doctors to take action as soon as the patient arrive at hospital

Applications: Wildlife Research Telemetry is now being used to study wildlife, and has been particularly useful for monitoring threatened species at the individual level. Animals under study may be fitted with instrumentation ranging from simple tags to cameras, GPS packages and transceivers to provide position and other basic information to scientists and stewards.

Applications: Defense, Space and Resource Exploration Systems Telemetry is an enabling technology for large complex systems such as missiles, RPVs, spacecraft, oil rigs and chemical plants because it allows automatic monitoring, alerting, and record-keeping necessary for safe, efficient operations. Space agencies such as NASA, ESA, and other agencies use telemetry/telecommand systems to collect data from operating spacecraft and satellites. Telemetry is vital in the development phase of missiles, satellites and aircraft because the system might be destroyed after/during the test. Engineers need critical system parameters to analyze (and improve) the performance of the system. Without telemetry, these data would often be unavailable.

Other Applications Rocketry: Telemetry equipment forms an integral part of the rocket range assets used to monitor the progress of a rocket launch Energy monitoring: In factories, buildings, and houses, energy consumption of systems such as HVAC are monitored at multiple locations, together with the related parameters (e.g. temperature) via wireless telemetry to one central location Water management: Telemetry has become indispensable for water management applications, including water quality and stream gauging functions Agriculture: Most activities related to healthy crops and good yields depend on timely availability of weather and soil data. Wireless weather stations play a major role in disease prevention and precision irrigation