You are here: GPS and radio comms team up

   Once exclusively a tool for the military, today's highly accurate Global Positioning System (GPS) receivers provide the ability to know where you are instantly, with an accuracy of within 10 meters (approximately 32 feet). With a GPS in your...

   Once exclusively a tool for the military, today's highly accurate Global Positioning System (GPS) receivers provide the ability to know where you are instantly, with an accuracy of within 10 meters (approximately 32 feet). With a GPS in your vehicle, or even in your pocket, you are never lost. But knowing where you are is only half the battle for first responders. It's just as important that other people, particularly dispatchers, can locate you.

   While devices that automatically track vehicles have been around for some time, the ability to remotely locate an individual officer on foot has been a weakness of traditional Automatic Vehicle Location reporting systems. Once an officer exits the squad car to conduct an investigation, interview a witness, or pursue a suspect, these AVL systems leave the dispatcher with no way to automatically determine where the officer is.

   New technology is changing that by taking the location reporting equipment out of the vehicle and placing it directly into the hands of the individual officer. This type of integrated technology allows truly personal location reporting by integrating a GPS receiver and data modem into a common remote speaker microphone, connected to the officer's portable two-way radio.

   The PRYME GPSMIC is capable of sending data messages containing the user's location coordinates over a normal voice radio channel. Reports are sent at various programmed intervals, such as when the user presses the Push-to-Talk button on the microphone, after a set period of time has elapsed, or when the user has moved a certain distance from the last reported location.

   These location coordinates are received by radio and computer equipment located at the dispatch center. Special software displays the locations on a map as they are received, allowing the dispatcher to know where individual officers and vehicles are at all times.

Practical application: search and rescue ops

   Among the adopters of the geo-location technology is the Santa Barbara County Sheriff's Department Search and Rescue (SBCSAR) Team. The team deploys its volunteer members on an average of two incidents per week in the beautiful but sometimes dangerous wild areas of coastal Southern California. The types of incidents SBCSAR handles are diverse and include searching for lost or missing persons, assisting in evacuations during wild fires, helping to secure evidence at remote crime scenes, responding to reports of downed aircraft, and handling many other types of wilderness medical emergencies including swift-water and high-angle rock rescues.

   Although SBCSAR members are highly trained in search and rescue protocols, the team operates in small groups in remote areas, so the individual safety of each team member is a major concern. It was clear to Nelson Trichler, an incident commander and public information officer for the team, that an over-the-air based GPS tracking solution was needed. Trichler explains: "Each officer can carry a GPS receiver with them so that they know where they are, but that doesn't help you find them if they are incapacitated and unable to answer radio calls."

   The geo-location reporting mic offered a possible solution: with each search team and SAR vehicle equipped with a GPSMIC, it would become possible to easily track officers while they respond to incidents. In fact, there were several capabilities which made this equipment an attractive solution for the team's search and rescue operations. One of the main advantages: compatibility with a wide variety of two-way radios, including the Kenwood portable radios that the team was already using. And because the location reports are sent over the voice radio channel, a dedicated data channel or any additional radio system backbone are not required. This meant that the system could be deployed quickly and with a minimum of infrastructure and expense.

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