Design of a GPS/GSM based Tracker for the Location of Stolen Items and Kidnapped or Missing Persons in Nigeria

摘要

The high rate of kidnapping in Nigeria is fueled by the inability of security agencies to quickly identify theudlocation of the kidnapped persons. This system combines the position location capabilities of the GPS (Global PositioningudSystem) to identify the current location of the kidnapped person or stolen items. These coordinates are time stamped,udaccessed by the microcontroller and sent to predetermined mobile phones via the GSM network. The GPS readings areudaccessed at short regular intervals but only the latest five readings are stored per time and these five readings areudtransmitted on demand by the GSM modem under the control of the Microcontroller upon the receipt of a location requestudSMS. The system monitors the GSM signal strength as the tracked object or person moves and when the GSM receivedudsignal strength falls below a predetermined threshold value, an alert together with the last five location data is sent to theudmonitoring mobile phones and the control center notifying them that the tracked object is approaching an area withoutudGSM coverage. The system is designed to be permanently on and it is run on batteries that can last for very long periodsudbefore requiring a recharge. The unit is designed to be attached to the clothing or strapped on the tracked person in such audway that it can not be easily identified or removed. It also has a panic button which can be activated during an emergencyudto send the location data to the predetermined numbers.