Close range radar sensor for measurement of sugar-cane level inside a chute

The control of the level of sugar cane in the chute feeding the shredder at the input of a sugar mill is an important parameter in determining the efficiency of the overall milling process. This paper describes the design and testing of an X-band frequency radar system built to measure the cane level in a shredder chute. This system uses a high gain horn antenna mounted inside the chute to illuminate the target area. The radar system measures distance using a modified, Frequency Stepped Continuous Wave (FSCW) technique. The measured data is processed to remove interference resulting from the finite isolation of the radar electronics and reflections from the aperture of the antenna. Testing of a prototype system shows that distance can be measured to an accuracy of about /spl plusmn/1 cm at a rate of 1 measurement per second.