Editing Automotive navigation system (section)

===Original factory equipment===
Many vehicle manufacturers offer a [[satellite navigation device]] as an option in their vehicles. Customers whose vehicles did not ship with GNSS can therefore purchase and [[retrofit]] the original factory-supplied GNSS unit. In some cases this can be a straightforward "plug-and-play" installation if the required wiring harness is already present in the vehicle. However, with some manufacturers, new wiring is required, making the installation more complex.

The primary benefit of this approach is an integrated and factory-standard installation. Many original systems also contain a [[gyrocompass]] and/or an [[accelerometer]] and may accept input from the vehicle's [[wheel speed sensor|speed sensors]] and reverse gear engagement signal output, thereby allowing them to navigate via [[dead reckoning]] when a GPS signal is temporarily unavailable.<ref>''In-Car Positioning and Navigation Technologies—A Survey'', I. Skog, and P. Händel, [https://dx.doi.org/10.1109/TITS.2008.2011712]</ref>  However, the costs can be considerably higher than other options.