Methodology Comparison for Effective LAI Retrieving Based on Digital Hemispherical Photograph in Rice Canopy
The paper investigates methodology comparisons for retrieving ef-fective leaf area index (LAI) using digital hemispherical photograph (DHP) in rice canopy. A set of self-making DHP instrument equipped with a fish-eye Len is utilized to acquire DHP in rice canopy, and some self-developing DHP proc-essing procedures are utilized to pre-process DHP and extract effective LAI from DHP (LAIDHP) rapidly. Based on Beer-Lamberts law and gap fraction that computed from DHP, four methods of single zenith angle (SZA), Lang, Mill formula(Mf) and iterative formula(IF) are used to derive LAIDHP(effective LAI from them are called LAISZA, LAILang LAIMf and LAIIF .respectively). LAISZA, LAILang, LAIMf and LAIIF are inter-compared and are also compared with from AccuPAR LP-80(LAIapar) and direct manual method (LAIdirect). It is found that, in general, LAIsza. LAILang LAIMf and LAIIF are similar to LAIapar, but slightly lower than LAIdirect. During their intercomparsion, LAILang is more similar to LAIAPAR than other three and LAIMf is more similar to LAIdirect, while LAIsza and LAILang are almost the same. It is implied that Lang method outperformed the other three when compared with AccuPAR LP-80 and Mill formula method outperformed the other three when compared with direct manual measure.
Rice Canopy Digital Hemispherical Photograph Effective LAI Methodology Comparison
Lianqing Zhou Guiying Pan Zhou Shi
Institute of Remote Sensing and Information System, College of Environmental & Resources Science, Zhejiang University, Hangzhou, P. R. China
国际会议
南昌
英文
71-82
2010-10-22（万方平台首次上网日期，不代表论文的发表时间）