Design of Portable Instrument for Measuring Agriculture Field Size Based on GPS

Global Positioning System GPS plays an important role in precision agriculture. Applying positioning function of GPS, this paper researches on portable instrument for measuring field size. Instrument consists of low-cost GPS module, data acquisition board in microcontroller, large capacity EEPROM storage, RS232C communication interface, keyboard and LCD display. GPS position information acquisition technology, method for calculating polygonal fields geometric size, software and hardware design principles of instrument , GPS measuring error analysis and accuracy control of instrument are provided. Experiment results prove that measuring instrument can fast measure geometric size of fields in any shape, relative measuring error is less than 2.5% , and the bigger the size of field is, the higher the measuring accuracy is.