The Research On Field Information Collection System Based On Palm-Sized PC

Precision farming, a technology category which included mutli-subjects is a system engineering combining agriculture, agriculture machine and information technology. Precision farming is a kind of agriculture management system based on information system. The base of this technology is acquiring variability of spatial and temporal of crop yield of small section, and analyzing reasons of influence yield variability of small section according to the role of all factors in crop growth, then doing a decision-making by GIS, and adopting the measure of melody-control which is feasible in technology and effective in economy, and making a difference countermeasure between small sections and based on the needs of different small sections to realize orientation melody-control.The idea of the precision farming is great and rational, but to make this kind of idea into reality is always difficult. First, a lot of technological problems must be resolved. In fact, these kinds of problem are how to use those advanced new technologies into agricultural domain. Because of the particularity of agricultural production, these process must produce the need of new theory research and the invention of new technology. And to the author, most of the precision farming research is correlative to these parts of work. And the research of this paper is parts of these work.The research in this paper is composed of two parts.(1) The analysis, design and programming of the farm information collection and processing system based on Palm-sized PC: In this part, after grasped the characteristic of Palm-sized PC and the special develop tools, Object - Oriented method is adopted to analysis the objects in a farm and the classes of the system is designed with some classical design patterns used for reference. The farm model is the first important result of this part. This model can greatly describe a farm in program, and make realize of sample process a bit comparatively easily.The next important result is the realize of the system. Because of the limits of the software and hardware of the Palm-sized PC, there is alse some specail points on the realize of the system. And in this section , 5 sample-plan is designed and programmed on the base of the farm model. And a spatial analysis method is also realized. So this system can be used to collect farm information, and then usethese limited information to estimate the information of the whole farm field. Because the system run at Palm-sized PC, so some code is designed to reduce the hardware limit. For example, the points directory is realized through AVL tree. And a memory class is designed to reduce the memory fragment.(2) The GPS precision analyze: in precision farming, GPS is also a part of field information. So in this paper, the precision of agriculture GPS:Agl32 is analyzed first. These analysis is based on a great deal of test. Some conclusion is: Geometry dilution of precision and the number of satellites can be used to pick out some abnormal points. To group the data according to the vertical dilution of precision can also pick out some abnormal points. To find out the best test time, a convenient method is put forward.And according to the test data, we got the horizontal point precision of Agl32: about 80.9% points located in a circle with one dims radius,about 0.52m, about 92.7% points located in a radius with two drms circle.about 1.04m. The presion of moving differential measure is 2.5m. The minimum field border must be less then 3m if static differential measure is usedo And if the moving differential measure is used.the minimum field border must be less than 5m. These research work will help us to use Agl32 properly.