ABSTRACT
Lidar is an effective remote sensing method to obtain the vertical distribution of aerosols, and how to select the aerosol extinction-backscattering ratio (AE-BR) during the inversion process is a key step to guarantee the accuracy of the lidar inversion of aerosol optical thickness (AOD) and aerosol extinction coefficient profile (AECP). In this paper, an inversion algorithm for AOD and AECP based on a genetic BP (GA-BP) neural network is proposed. Simultaneous measurements are carried out using CE318 sun photometer and lidar, and the mapping relationship between the lidar echo signal and AOD is established based on the genetic BP (GA-BP) neural network method, which achieves the accurate inversion of AOD with an absolute error mean value of 0.0156. Based on the AOD output from the GA-BP neural network, the real-time best AE- BR to improve the inversion accuracy of AECP. Finally, practical tests show that the method achieves accurate inversion of AOD, determines the range of AE-BR from 20-50sr, realizes real-time dynamic correction of AECP, and has strong generalization ability and applicability in practical situations.
ABSTRACT
In order to explore the ecological factors affecting the growth of Astragalu smembranaceus var. mongholicus, we investigated the resource distribution, habitat characteristics and growth conditions of wild and cultivated A. membranaceus var. mongholicus by fixed-plot observation, survey method, and literature. These data were analyzed by traditional Chinese medicine GIS-2 (TCMGS-2) to obtain the most suitable areas of A. membranaceus var. mongholicus within Inner Mongolia. The results showed that the production areas of cultivated A. membranaceus var. mongholicus were mainly located in Wuchuan County, Guyang County and other 15 counties, which were cha-racterized by the altitude higher than 1000 m, with soil type of sand, gravel and calcareous clay. The wild A. membranaceus var. mongholicus was distributed mainly in the eastern Inner Mongolia and germinated in sunny place, which preferred to the cold dry climate and sandy loam soil or gra-vel but avoided damp heavy clay soils. There are 43 counties of 94460.30 km2 for wild A. membranaceus var. mongholicus, and 32 counties of 76013.93 km2 for cultivated one within Inner Mongolia, with a similarity coefficient of ecological factors greater than 95%.
Subject(s)
Astragalus propinquus/growth & development , Climate , Ecosystem , China , Germination , Plants, Medicinal/growth & development , SoilABSTRACT
Principal component analysis (PCA) and correlation analysis (CA) were applied to analyze the correlation of the main chemical components in Astragalus membranaceus var. mongholicus and ecological factors. The results showed that the contents of astragaloside, campanulin, ononin, kaempferol and astragalus polysaccharides (APS) of A. membranaceus var. mongholicus produced. in Shanxi were significantly higher than in Inner Mongolia and Gansu. The main climatic factors for affecting the contents of chemical ingredients in A. membranaceus var. mongholicus were annual average relative humidity, sunshine hours and average July temperature. Calcium was the main factor in the soil affecting the chemical ingredient contents, and calcium was negatively correlated with the contents of calycosin glycosides, kaempferol, ononin, quercetin and APS in A. membranaceus var. mongholicus within a certain range.
