While most people live within cellular coverage, only 25% of the world’s landmass is served by cell towers. Yet, there is a growing need to collect environmental data across the entire globe. The information collected helps to proactively respond to immediate disasters such as wildfires and hurricanes, or protracted conditions like drought.
When real-time data is required to capture environmental events, the geographical location can determine what equipment is required and what forms of telemetry are possible to ensure the information is obtained promptly. As to be expected, there are a variety of options to select from and each has its advantages and disadvantages. This post will compare and contrast the most common telemetry options used in the meteorological and hydrology fields today.
Cellular is pervasive in urban areas and expanding every year. When the conditions being monitored are within cellular coverage, using this form of telemetry will provide low-cost, high-data rate, bi-directional communication. The ability to transmit high frequency data is especially helpful in revealing short burst anomalies; and being able to communicate with a station remotely reduces sits visits. As an added benefit, cellular transmissions have built in security protocols to help reduce the potential of data tampering.
The primary concern of using terrestrial based technology like cellular, is its vulnerability during sudden disasters such as fires, hurricanes, floods. Local capacity of cellular networks can be overwhelmed in an emergency or the infrastructure can be damaged, interrupting data flow. Because this information has immediate relevance, emergency responders may miss valuable data necessary for making informed decisions and protecting human life. In many cases, a non-terrestrial based backup system can be coupled with cellular to ensure data continuity from key assets during major events. Optionally, dedicated networks may be provided to first responders to ensure they have access to fast, secure, and reliable communications. FTS offers a variety of cellular options: LT1-CELL, Ubicom Cellular Modem, and MWS Cellular.
Image credit: ICU
Collecting and transmitting environmental data via GOES (Geostationary Operational Environmental Satellite) has been the defacto choice for Western Hemisphere Earth observations since NASA and NOAA jointly sent up the first satellites in 1966.
Advantages of this communication method include:
- Low-cost: once the transmitter and antenna are purchased, data transmissions are free to users
- 100% ground coverage: where the satellites orbit, see image, GOES provides access to remote regions that are otherwise unreachable
- Disaster resistance: stations are designed to withstand extreme weather events and continue to transmit
A typical GOES station operates on an hourly transmission schedule with the option to broadcast triggered messages at irregular intervals using the random channel; this restriction limits GOES transmissions from being precisely real-time. The satellite service is owned by NOAA making the data publicly available and, due to the system design, communications are one-way; therefore, programming of the station must be done locally on site. FTS offers a range of GOES options: A standalone CS2 GOES/Meteosat Transmitter, the same transmitter enclosed in our rugged Axiom datalogger, or the compact LT1–GOES.
Image credit: NOAA
The Iridium constellation provides pole to pole coverage. Having launched its commercial service in 1998, it has used the last 20+ years to establish a reliable communication platform adopted by public and private organizations around the globe.
- Data security
- High data frequency
- Bi-directional communication
However, transmission costs can be high depending on frequency and payload size. Typical cellular costs are in the dollar per MB range, whereas Iridium costs are in the dollar per KB range. Devices designed to communicate over Iridium devote significant effort to ensure messages are short and transmissions may be as infrequent as once a day or only when relevant information has been collected, for example an alert has been triggered due to high waters.
The US Department of Defense awarded Iridium the contract to provide unlimited satellite services for the next several years. Federal organizations may petition the DoD to utilize this carrier at a moderate annual rate of approximately 5x a typical cellular plan. This option has all the advantages of using commercial Iridium: real-time transmissions, data security, bi-directional communications, and global reach. It then adds unlimited data rate and message size, making Iridium DoD a powerful telemetry choice. The FTS Ubicom Iridium and MWS Iridium can be configured for either the Commercial or Iridium DoD network.
There is no one size fits all when monitoring the globe.
Each site requires analysis and decisions are based on location, significance of the data, frequency of transmission, etc. Speak with our trained personnel to select the optimum telemetry path for your locations. Contact us.