Map-Matching

Definition

Sampling vehicular movement using GPS is affected by error sources. Given the resulting inaccuracy, the vehicle tracking data can only be related to the underlying road network by using map-matching algorithms.

Main Text

Tracking data is obtained by sampling movement, typically using GPS. Unfortunately, this data is not precise due to the measurement error caused by the limited GPS accuracy, and the sampling error caused by the sampling rate, i.e., not knowing where the moving object was in between position samples. A processing step is needed that matches tracking data to the road network. This technique is commonly referred to as map matching.

Most map-matching algorithms are tailored towards mapping current positionsonto a vector representation of a road network. Onboard systems for vehicle navigation utilize dead reckoning besides continuous positioning to minimize the positioning error and to produce accurate vehicle positions that can be easily matched to a road map....