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Electronic Bracelets
| Applications | |
|---|---|
| Title | Electronic Bracelets |
| Author(s) | Rui Barradas Pereira. |
| Level | Basic |
| Year of Publication | 2011 |
The Electronic Bracelets are an example of personal tracking products, meant to control prison populations, house arrests or protecting victims of crimes.
These systems are design to serve as alternative to prison for situation determined in trial, as well as to monitor post-sentence behaviors for some sort of crimes, such as child molesters or other types of sex offenders.
Product Description
The most obvious association with GNSS bracelets is the tracking of persons charged with a crime that require home monitoring.
Although, the electronic bracelets are becoming a common alternative to incarceration and to provide a control and accountability structure for selected probationers, as well as to provide an extra layer of supervision to the community at large.[1]
This system consists in the bracelet equipment applied in the offender and by a secure command and control website, operated by the police officers, which has the capability to display offenders awareness situation and keep a registry of activities.
The Electronic Bracelets systems usually offer the following capabilities:
- Home facilities geofence: In case an offender leaves his or her home at a time not authorized by a judge, an alert (auditory and visual) indicates that the probationer is out of the defined geofence.
- Prevent destruction or removal: In case the bracelet is removed or destroyed, a sensor will indicate this violation and an alert is arise in the command and control website.
- Track an evasion: In case the offender steps away out of the defined geofence, an arrest warrant is issued and the suspect can be easily tracked.
- Grant a restrained freedom: In some situations some offenders can continue to carry their jobs within a defined geofence, without issuing an alert.
- Detection of infractions: This systems can also be programmed to detect speeding situation, when the offenders are allowed to drive.
- Victims protection: The geofence mechanism can also be used to detect if the offender enters in forbidden areas, for instance in domestic violence or child molester situations. In domestic violence case, if the offender happens to enter in an exclusion geofence, the police can act and notify the victim about the situation.[2] Vicinities of schools can also be defined as exclusion zones for child molesters, forbidden to be nearby these facilities.
These products are considered as non-critical products.
The accuracy required by these applications is low. The current accuracy provided by civilian GPS is enough for these applications. Availability, however, can be reduced due to urban environments, but it can be improved with the Assisted-GPS technology.
Product Characterization
The offenders tracking devices are the most evolute electronic bracelet devices and some systems are able to integrate GNSS with other legacy technologies.
The systems used for keep tracking of persons charged with a crime are now moving from RFID to GNSS technology, which grants a more reliable product in terms of tracking needs.
The GNSS bracelet devices are labeled in two different types, the active and the passive units:[3]
- Active units: These devices collect the offenders data and position in real time, leaving little chance for the tracked person to trespasses the geofence. The GNSS devices send the data to the command and control website which allow the police officers to get the location of the offender immediately.
- Passive units: These devices collect the offenders data, that is stored throughout his daily activities. The person tracked connects the unit daily in a docking station. This station is plugged into a power outlet, to recharge the device, and to the offenders home phone line. The police officers then evaluate the data through the command and control website website to verify where the offender was through the course of the day.
The data collected is based on few different variables, such as position information, which allow to pinpoint the positions in a map. The offenders direction, traveling speed, time of day and date can be all monitored, for both types of units.
Product Examples
The following Manufacturers are producing GNSS Electronic Monitoring Devices and appication platforms for house arrests[4]:
- Tarheel monitoring
- Quest Guard
- Safe Tracks
- iSECUREtrac GPS-based systems consisting of a Personal Tracking Unit and a web based platform.
- BI Behavioral Interventions
Notes
References
- ^ The Electronic Monitoring Program - 2010 Fact Sheet - The Massachusetts Probation Service
- ^ GPS bracelets would deter domestic violence
- ^ eHow.com How Does a GPS Ankle Bracelet Work?
- ^ GPS practice and fun site - Offender tracking