Abstract: Two kinds of sensors are in use for the measurement of the travelled distance of a vehicle, viz. the odometer and accelerometer. The odometer measures the number of revolution of the vehicle <wheel and outputs a series of TTL - compatible pulses. The scale factor is affected by the road conditions and therefore needs constant correction or updating. The accelerometer, however, has the advantage of being very accurate in short time measurements. The paper discusses the design principle, formulae and results of digital simulation of a new version of combinatory navigation making simultaneous use of the odometer and accelerometer.