This paper presents a comparison of the available electronic techniques for distance measurement suitable for the off-highway environment. The main techniques described are:
ultrasonic
passive infrared
laser radar
FMCW radar
impulse radar
capacitive
vision
The techniques are compared across a number of key parameters, including sensitivity, measurement range and cost. A brief description of some of the disadvantages is also included. Finally the paper discusses the use of sensor fusion techniques to overcome the inherent disadvantages of particular techniques.