1. Key Laboratory of Digital Earth Sciences, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100094, China 2. School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
Abstract：Being orientated to the low prescion of crop leaf area index (LAI) inversion using the same spectral vegetation index during different crop growth stages, the present paper analyzed the precision of LAI inversion by employing NDVI(normalized difference vegetation index). Ten vegetation indices were chosen including six broad-band vegetation indices and four narrow-band vegetation indices responding to vegetation cover to inverse LAI in different growth stages. Several conclusions were drawn according to the analysis. The determinant coefficient (R2) and root mean square error(RMSE) between LAI inversion value and true value were 0.558 5 and 0.320 9 respectively during the whole growth duraton. The mSR(modified simple ratio index) index was appropriate to inverse of LAI during earlier growth stages (before jointing stage) in winter wheat. The R2 and RMSE between LAI inversion value and true value were 0.728 7 and 0.297 1 respectively. The SR(simple ratio index) index was suitable enough to inverse of LAI during medium growth stages (from joingting stagess to heading stagess). The R2 and RMSE between LAI inversion value and true value were 0.654 6 and 0.306 1 respectively. The NDVI(normalized difference vegetation index) index was proven to be fine to inverse LAI during later growth stages(from heading stage to ripening stage). The R2 and RMSE between LAI inversion value and true value were 0.679 4 and 0.316 4 respectively. Therefore it was indicated that the results of LAI inversion was much better inverse of winter wheat LAI choosing different vegetation indices during differen growth stages for winter wheat according to the change of vegetation cover and canopy reflectance than merely with NDVI to inverse LAI in the whole growth stages. It was concluded that the precision of LAI inversion was significantly improved with segmented models based on different vegetation indices.
Key words：Winter wheat;Growth stages;Vegetation indices;Leaf area index;Inversion
[1] Chen J M, Black T A. Plant, Cell & Environment, 1992，15(4): 421. [2] Via A, Gitelson A A, Nguy-Robertson A L, et al. Remote Sensing of Environment, 2011，115(12): 3468. [3] Pinty B, Lavergne T, Widlowski J L, et al. Remote Sensing of Environment, 2009，113(1): 10. [4] LI Xin-chuan, XU Xin-gang, BAO Yan-song, et al(李鑫川, 徐新刚, 鲍艳松, 等). Scientia Agricultura Sinica(中国农业科学), 2012，45(17): 3486. [5] Haboudane D, Miller J R, Pattey E, et al. Remote Sensing of Environment, 2004，90(3): 337. [6] Yang F, Sun J l, Fang H L, et al. International Journal of Applied Earth Observation and Geoinformation，2011. doi: 10.1016/j.jag.2011.09.004. [7] Verrelst J, Schaepman M E, Koetz B, et al. Remote Sensing of Environment, 2008，112(5): 2341. [8] Hasegawa K, Matsuyama H, Tsuzuki H, et al. Remote Sensing of Environment, 2010. 114(3): 514. [9] Liu J, Pattey E, Jégo G. Remote Sensing of Environment, 2012，123: 347. [10] Rouse J. Proceedings of the 3rd ERTS Symposium, 1973, 1: 48. [11] Tucker C J. Remote Sensing of Environment, 1979，8(2): 127. [12] Liu H Q, Huete A. IEEE Transactions on Geoscience and Remote Sensing, 1995，33(2): 457. [13] TIAN Qing-jiu, MIN Xiang-jun(田庆久, 闵祥军). Advances in Earth Science(地球科学进展), 1998，13(4): 327. [14] ZHAO Ying-shi(赵英时). The Principle and Method of Analysis of Remote Sensing Application(遥感应用分析原理与方法). Beijing: Science Press(北京：科学出版社)，2003. [15] Rondeaux G, Steven M, Baret F. Remote Sensing of Environment, 1996，55(2): 95. [16] Datt B. Journal of Plant Physiology, 1999，154(1): 30. [17] Broge N H, Mortensen J V. Remote Sensing of Environment, 2002，81(1): 45. [18] Gonsamo A, Pellikka P. ISPRS Journal of Photogrammetry and Remote Sensing, 2012，70: 15. [19] Huete A R, Remote Sensing of Environment, 1988，25(3): 295. [20] Pinty B, Verstraete M M. Plant Ecology, 1992，101(1): 15. [21] Gitelson A, Merzlyak M N. Journal of Plant Physiology, 1994，143: 286. [22] Vogelmann J E, Rock B N, Moss D M. International Journal of Remote Sensing, 1993，14(8): 1563. [23] WANG Ji-hua, SONG Xiao-yu, LI Cun-jun，et al(王纪华, 宋晓宇, 李存军, 等). Journal of Remote Sensing(遥感学报)，2005，9(3): 323. [24] Houborg R E, Boegh. Remote Sensing of Environment, 2008，112(1): 186. [25] Martínez-Beltrán C, Jochum M A O, Calera A, et al. International Journal of Remote Sensing, 2009，30(5): 1355. [26] Maselli F, Chiesi M. International Journal of Remote Sensing, 2006，27(1): 55.
