| Global Positioning System (GPS) |
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A GPS receiver can be interfaced to the OTMR then, via a low profile antenna mounted on the roof of the vehicle, accurate positional data can be determined and logged by the OTMR. Logging of the positional data is performed regularly, both after a specific time interval has elapsed or after a set distance has been travelled, whichever occurs first. A number of digital inputs can also be used to trigger logging of positional data. For example the 'door-open' status could be used to log the exact location of the vehicle when the doors were opened.As the analyser software develops it is intended to provide a data base of longitude/latitude references against signal numbers, platform, etc, so that the information is automatically decoded and the position is shown in English text. This already happens for the ATP system where a data-base of zone and beacons is included in the software. In addition to positional information GPS can be used to determine an accurate date and time stamp to keep the OTMR Real Time Clock accurate at all times. |
