The Study On Methods Of GPS Data Processing And Positioning In Precision Agriculture

In order to attain high accuracy of GPS satellite navigation, positioning and low cost in precision agriculture, it is studied a method of GPS Pseudo-range observation and Carrier phase measurement to combine the actual conditions of agriculture. It is presented a method of high accuracy positioning and measure based on GPS OEM board in this paper, and proved the feasibility of key technology with emulations and field tests. The main contents of the study are as follows:1. To Jupiter GPS OEM board receiver of the low cost, the software was developed according to the original data of satellite, the primitive observation data of receiver and GPS theory of technology based on GPS Pseudo-range observation and Carrier phase measurement.2. By means of a study of kalman filtering of CA model and current statistical model on a kinetic vehicle, It is put forward a method of the adaptive kalman filtering with error feedback, in order to solve the trouble about the kalman filter model and solve the issue which a wrong parameter is chosen to cause a result badly, even dispersed.3. Based on the theory of analysis methods which include wavelet, wavelet packet and feedback adaptive kalman filtering, it is put forward a proposition combined with wavelet packet and feedback adaptive kalman filtering, in order to result comparative smooth to the signal tested when it is being relatively steady, and extreme strong traceability goal to the signal tested when it is taking place sudden change.4.To the situations of short-baseline, a genetic algorithm of search for ambiguity solution with horizontal model is studied. Using the non-sensitive characteristic of Ambiguity Function Method (AFM) regarding cycle slips, it is sufficiently exerted the characteristic of genetic algorithms which are optimization for ambiguity solution on-the-fly.5. In order to solve the troubles about the fitness function of genetic algorithms which meet many peak during search for ambiguity solution, it is presented a genetic algorithm graded, on the one hand, the precision to repeatedly search for ambiguity will be improved; on the other hand, it will be solved that the algorithm of positioning has nothing to do with ambiguity solution.6. It is adopted wavelet analysis to examine cycle slips. Modification of cycle slips will use a Symmetrical method. In this way, it will be more accurate to examine cycle slips and more precise to modify that. In fact the method can perfectly prognosis the trace of GPS carrier phase.7.Based on the comparison with dual band GPS phase and C/Acode, ambiguity function method, least squares search, ambiguity solution covariance, cholesky disintegrate and least square ambiguity decorrelation adjustment, it is considered the method of ambiguity function using double GPS antennas to move baseline and the equation of dual differential carrier phase. According to the characteristic of movement which velocity of agricultural machinery is lower as well as near a level in farm, it is studied attitude determination with lower pitch and the speed determination, in order to achieve thehigh-accuracy's piuposes of GPS positioning, navigation and measure.8. Considering the actual conditions of precision agriculture, the method of GPS dynamic surveying automatically tracing a kinetic vehicle is studied. By means of decrease in differential reference stations and the communication with mobile GPS, we will realize the good economic goal what include GPS construction cost of navigation system and operate cost.9. In order to meet the demands which are positioning and measure of speed about the grain yield in combine, it is studied that the method is on-line recording the message on grain yield, moisture, position and speed, and then deal with GPS data in high accuracy.10. A experiment is done which apply the GPS surveying technology to yaw and speed of the large-scale irrigation system in remote control with other auxiliary sensors. It is shown that GPS high accuracy surveying technology based on carrier pha...