ABSTRACT
Recently, there are many commercial products of Light-bar Guidance System such as Parallel Swath Option (PSO) of Trimble Company and Centerline Guidance Light-bar of Mid-Tech Company. The agricultural machines' guidance system has become the important equipment of many farms in EU and USA in recently years. Using the GPS guidance system can improve the operation quality and efficiency, prolong the machines' operation time in the crucial harvest season, and alleviate the labor intensity of operators . So these systems are very popular for farmers in the developed countries. According to a survey of Purdue University in 2005, there are 76% of informants used some kind of precision agriculture technologies, 60% used GPS guidance system . Furthermore, some foreign researchers do many researches and experiments on the light-bar guidance precision. Buick and Lang researched and analyzed the precision and efficiency between foam marker method and DGPS light-bar guidance system through experiments in 1998.
