Firehouse Magazine, March 2006
Getting the Most from Your Wireless Transmitter
By Jonathan Bastian
Without question, thermal imagers (TIs) have revolutionized the way modern firefighters perform their tasks. Firefighters using TIs are now able to see what smoke has hidden from their predecessors. The TI helps firefighters see fire behind walls and locate victims lost in smoke. Normally, only the firefighters near the TI can benefit from its image. However, thermal imagers can be equipped with a wireless video transmitter that allows firefighters to share the TI image with incident commanders. Proper use of this tool can help officers and firefighters make better, more informed decisions.
The Basics
Every fire service TI is available with a remote video transmission system. Many of the systems on the market must be installed by the manufacturer, although a fair number of TIs allow the user to buy and add a transmitter at his convenience. These systems operate in the 2.4 GHz frequency range, which is a domain used by a number of household items (including certain cordless phones).
The transmission system can be analog or digital; neither is inherently better than the other, as each has specific advantages. Digital systems are “all or nothing,” which means that they will generate a very good image or none at all. Analog systems can have static that indicates interference; however, poor signals may still be visible through the static.
Most wireless transmitters send a 300-400 mW signal, which is about 1/15th the strength of a firefighter’s normal portable radio. Most transmitters offer a normal transmitting distance of about 300 feet through a standard wood-frame residence. Heavier construction or a great number of walls and obstacles between the transmitter and receiver will reduce the effective distance.
Three basic receiver systems are available on the market. Fixed receivers are hardwired into a vehicle’s power supply and connected to a larger antenna. Some manufacturers offer portable receiver systems, which are self-contained and allow a commander to set up the equipment quickly and easily at a chosen location. There are also mobile receiver systems, which are compact receiver/display components that allow the user to employ the product while he is moving on scene. The performance of all three types of systems can be enhanced by ensuring as clear a line as possible between the transmitter and the receiver antenna. The portable and mobile systems will perform better with a fully charged battery than with a partially discharged one. When using one of these systems, be sure to carry a spare battery, just in case reception degrades due to lower power.
The Uses
By transmitting a thermal image to another location, interior firefighters can gain a number of advantages. For example,
- Incident commanders can “see” what their fire companies are seeing. This allows the IC not only to provide guidance to interior companies, but also to observe interior heat conditions. The incident commander can determine if interior operations are still acceptable by identifying improving or deteriorating conditions. He can also monitor changes within the incident to evaluate his strategies and tactics.
- A safety officer can use a portable or mobile receiver system to compare what he sees on the exterior with the thermal image from the interior. Dangerous visual cues on the exterior may be confirmed, or contradicted, by the thermal image sent by interior companies. The safety officer can then make more informed decisions regarding the overall situation.
- A plant manager can observe a fire company’s progress through a structure. By watching at the command post, he can help guide fire companies by radio through the facility to the exact seat of a chemical spill or fire. The plant manager could even direct fire personnel to safely and effectively shut down equipment that is contributing to the incident.
- Some manufacturers have special accessories that will attach a TI to a fixed location. During exterior operations, a TI can be mounted remotely at the top of an aerial ladder or platform. The TI can then transmit a “bird’s eye” view of a large fire to the IC. This can help the incident commander identify the seat of the fire and the effectiveness of master streams. Most importantly, this is done without placing a firefighter at risk by having him at the end of the ladder.
- In a training environment, instructors outside can monitor the teamwork and effectiveness of firefighters training in smoke or darkness. An instructor with a TI can follow the team for safety, transmitting the signal to other instructors outside. This can also be recorded and played back for the students as a learning review.
Challenges
There are two primary obstacles to using a wireless transmitter during emergency incidents: set-up time and manpower. Portable and mobile receiver systems eliminate the majority of set-up time. Fixed receiver systems can be permanently wired in place to eliminate set-up time. If the system must be set up and connected at an incident, firefighters can speed the assembly process by using color-coded tape to indicate which fittings belong on which attachment ports.
Manpower to handle transmitter and receiver operations is a more difficult challenge, one that cannot be addressed in a uniform fashion. While manpower is probably the most common and most obvious obstacle related to the use of transmitters, relatively few departments plan how to overcome it. Failure to plan guarantees failure to execute, so take time to develop a system that will work within the confines of your overall system. In some locations, it may be sufficient to train regularly on coordinated TI use, transmitter operations and fire operations. Other departments may need to divide some scene responsibilities, possibly appointing more sector officers to assume more operational responsibilities. Some departments may need a “chief’s aide” to help monitor IC responsibilities, including managing the transmitted signal. Each department needs to find its own solution.
Conclusion
The wireless transmitter is a common accessory, but it is generally not used as effectively as it could be. If fire departments plan their operations around TI use and train incident commanders on how to incorporate image reception into their tactics, they can improve the safety and effectiveness of their operations. For tips on improving the performance of a wireless system, visit the Technology section of Firehouse.com.
Again, please remember that for 2006, this column wants to address your stories of success and questions about thermal imaging. Please send them to jonathan_bastian@bullard.com.
 A mobile receiving system gives a firefighter the ability to move around the incident while receiving the transmitted signal. These are valuable tools for safety officers and sector officers. |
A portable receiving system allows an incident commander to establish a receiving station at a convenient location. This may be in
or near a vehicle, or even just outside an involved structure. |