Parametric error equations for dead reckoning navigators used in ground vehicle guidance and control

This paper develops and validates parametric error models for a GPS-aided dead reckoning navigator for ground vehicle guidance and control. The dead reckoning navigator fuses information from a rate gyro and a Doppler radar to provide a two-dimensional navigation solution during momentary GPS outages. When available, GPS is used to calibrate the dead reckoning sensor errors. The error models developed provide a quick and accurate method for predicting the navigator's performance during these momentary GPS outages. The models parameterize the navigation performance as a function of sensor quality, sensor sampling rate and GPS outage length. The error models are validated in a series of tests using a farm tractor. The models predict and the tests show that this dead reckoning system can provide a 61 deg heading and 0.3 m position accuracy during a 20-40 s GPS outage.