SAT NAV & GPS
Sat Nav / GPS Forensic Services
The huge growth in the use of Satellite Navigation / Global Positioning Systems in cars (either fixed or removable) and the more recent growth in such systems on Smartphones, PDAs, tablets, means that they can now be a useful evidence type in criminal cases.
We are receiving a growth in requests to look at the stored contents of such devices to help ascertain such information as:
- home location
- “favourite” stored addresses / locations
- manually entered addresses /locations
- journey starts, ends and last GPS fix of a device
- details of the last journey
- dates and times a journey was started
- paired mobile phone details
- paired mobile address book, call records and SMS
- deleted data
This data can be useful or critical in a whole range of case / crime types and we have been asked to analyse Sat Nav devices in, for example, drugs cases, death by dangerous driving, burglary and many others.
Global Positioning System
The accuracy of a Sat Nav’s position depends on how many satellites the device is currently receiving signals from. GPS receivers are a multi-channel device, which means they can receive a signal from multiple satellites at once. The higher the number of signals the greater the accuracy of the positional data. With a fix on at least 6 satellites the data is accurate to within 20 metres, when the fix is on 10-12 satellites then the accuracy is typically within 5 metres.
When a Sat Nav is used in a built-up area and hemmed in by tall structures the satellite signals will often bounce off the building’s exterior surfaces. These types of signals are called “multipath reflections” and may incorrectly report a device’s location up to hundreds of metres away.
The forensic examination of portable Sat Nav devices can add real evidential weight to your case. Forensic Access’ experts are experienced in recovering live and deleted data from multiple navigation devices. In addition to utilising industry leading software tools our experts are able to acquire additional data not typically extracted such as trip logs. Trip logs have proven to hold key additional data such as the device’s recorded location, for example, every twenty minutes. This method allows for previous routes to be plotted with more location points.
There are a huge amount of Sat Nav / GPS devices now on the market, from units built into a vehicle, to portable units and to Smartphones, PDAs and tablets, all with differing types of software and applications. We can examine such units in situ or at our laboratories. However, the amount of data we can retrieve is very dependent on the type of device.
It is also worth considering looking at other electronic devices located on the defendant / suspect or at the crime scene to see if they store complementary data that may be useful to the case (prosecution or defence).