关键词: 降水量, 格点数据, 行程编码, 无损压缩

Abstract:  Grid data is one of the important forms for the storage and exchange of the meteorological data. An efficient compression scheme is very important for the data compression, and a compression scheme must be lossless for the meteorological data. Precipitation is a special element because of its spatial and temporal discontinuity, so the lossless compression scheme used for those continuous elements is not suitable to the precipitation data. The fundamental features of the precipitation grid data were analyzed. Basing on the run length encoding (RLE) and Shuffle encoding as well as entropy encoding, a new lossless compression scheme was presented for precipitation grid data. The results show that the compression efficiency of the new scheme is high and it can greatly save storage space and the transmission time. The compressed data are completely lossless within available precision, so this scheme can be used for other meteorological elements with spatial and temporal discontinuity and has great practical application in meteorology.

Key words: Precipitation, Grid data, Run length encoding, Lossless compression