Application of GPS technology in agricultural land levelling survey

The application of GPS technology was evaluated by the measured elevation data and estimated earthwork quantity. The statistic analysis was applied for elevation data at the fixed points measured by GPS and level respectively. The influences of the different moving speeds of the mobile GPS on data precision were also discussed. Therefore, the possibility of using GPS technology to replace traditional level for elevation measurement was analyzed. The results indicate that there is good similarity for field microtopography maps measured by GPS and level and the two measuring methods have the same precision. The speed of mobile GPS presents obviously effects on GPS measuring precision. The data under slower moving speed reveals higher precision than that under faster moving speed. For this reason a relative low and stable moving speed under mobile GPS is of importance to ensure the data precision. The advanced GPS technology shows good potential to replace traditional land level for elevation measurement in agricultural land levelling project.