Algorithm Of Citrus Canker Warning System Of Meteorological Data Compression

With the introduction of China’s12th Five-Year Plan, the three rural issues become the focus of attention again. Agricultural informatization as the priority among priorities to solve the three rural problems has been attached great importance to and support of the party and the state. Citrus as China’s agricultural products with strong competitiveness, its development directly affect the daily life of the farmers, the city’s economic destiny, national agricultural products import and export pattern. Therefore, we must speed up to enhance the core competitiveness of Citrus in China itself, the key is to protect against work, reduce disaster losses and improve the yield and quality of citrus. Citrus canker is one of the major diseases and insect pests of citrus, which is pested by major domestic and international countries.lt can directly affect the normal growth and development of the citrus. And the current domestic and international diagnosis and early-warning of citrus canker is depending on agricultural technology personnel to visual diagnosis or laboratory test on the site.In this case, it is too late to effectively control the epidemic. Therefore, in order to nip in the bud and minimize the disaster and the loss, this paper presents of citrus canker disease early warning system, realize the exchange of information and knowledge between farmers, extension staff, experts.At the meantime, it can make some contributions to scientific guidance of citrus’normal growth.In the citrus canker warning system, meteorological information and historical data files should be uploaded to the server. As the acquisition cycle is short and there are many nodes, it will form a large number of historical data files without compressing.Thus, it will increase the server load, and ultimately cause the server store disaster. Therefore, these data files must be lossless compressed,however, commonly used compression software such as Winrar,Winzip which based on the principle of universal, without considering the characteristics of the meteorological data, can not achieve the desired compression effect. In view of this, this paper selects the LZW data compression algorithm which is used most widely to research. Based on the analysis of characteristics of LZW algorithm, we improved LZW algorithm in aspect of dictionary maintenance and management and design a new tuple dictional structure,use hash function to find phase to replace the traditional one-dimensional array traveral sequence, therefore.it could save the dictionary find time.Secondly,we cancel the dictionary initialization which is use256characters of the ASCII table, and reinitialize the dictionary based on the new disigned dictionary structure and data characteristics to save a certain dictionary storage space. Finally, by analysis of the existing dictionary management strategy, a new dictionary management strategy is proposed which is determined to remove and reconstruct dictionary by comparing the phase’s used count and the setting threshold. The improved algorithm is mainly for the dictionary, so we call this algorithm LZWD data compression algorithm. Due to LZWD compression algorithm is better in contextual relevance, so we use BWT tranform to preprocess the data.Thus,the same symbol could repeated continuously as far as possible.Then,we introduce the MTF Thought, and remapping the alphabet according to the meteorological data series. Eventually, we form the BM-LZWD compression algorithm. From the end of the simulation results, we can find that the BM-LZWD algorithm achieved good compression effect, especially in the aspects of compression ratio,it has a smaller file size than WinrAR, Winzip and7z.Therefore, it can be effectively used in the the citrus canker warning system.