The Santa Clara County Probation Department's Electronic Monitoring Program (EMP or EMP systems) includes the use of Global Positioning System (GPS) devices, Radio Frequency (RF) devices, and Alcohol monitoring devices, all of which shall be used pursuant to and in compliance with court orders. GPS, RF, and Alcohol monitoring devices are electronic transmitters that are attached to a person's ankle for court-ordered monitoring, as an alternative to serving custody time in juvenile hall or jail.
The (GPS) monitoring devices (currently Attenti WMTD Gen 4 GSM/ Attenti WMTD Gen 4 CDMA/ BI loc8) are designed to track the movement of a person for extended periods of time. The device uses standard GPS technology, whereby it identifies the person's location by coordinating with multiple GPS satellites. GPS is capable of updating a location every ten seconds and pinpointing location to within inches.
The (RF) monitoring devices (currently Attenti SB2000 RF/ SB3000 RF/ BI HomeGuard 200 (HG200)/ BI HomeGuard 206 (HG206)) send a signal to a Field Monitoring Device (FMD) receiver installed in a person's home. That FMD is in contact with the host network via telephone lines and modem. The RF device logs the person's movements in and out of their home.
The Alcohol monitoring devices (currently SCRAM CAM / SCRAM Remote Breath/ Soberlink-SL2) use standard GPS or RF technology to either read a person's location or log a person's movements in and out of their home. In addition, one alcohol monitoring device has a handheld portable breathalyzer, which allows a person to discreetly submit a Breath Alcohol Test from any location using cellular service. The second alcohol monitoring device is a transdermal alcohol monitoring device, which tests and reports alcohol consumption based on readings through the skin.
Information collected by GPS, RF, and Alcohol monitoring devices are streamed from the host networks to a web server operated by the host companies.