[1] Coppin P, Jonckheere I, Nackaerts K, et al. Digital change detection methods in ecosystem monitoring: a review[J]. International Journal of Remote Sensing, 2004, 25(9): 1565−1596. doi:  10.1080/0143116031000101675
[2] You H, Wang T, Skidmore A K, et al. Quantifying the effects of normalisation of airborne LiDAR intensity on coniferous forest leaf area index estimations[J]. Remote Sensing, 2017, 9(2): 163−179. doi:  10.3390/rs9020163
[3] Peduzzi A, Wynne R H, Fox T R, et al. Estimating leaf area index in intensively managed pine plantations using airborne laser scanner data[J]. Forest Ecology & Management, 2012, 270(4): 54−65.
[4] Sumnall M J, Fox T R, Wynne R H, et al. Estimating leaf area index at multiple heights within the understorey component of Loblolly pine forests from airborne discrete-return LiDAR[J]. International Journal of Remote Sensing, 2016, 37(1): 78−99. doi:  10.1080/01431161.2015.1117683
[5] 骆社周, 王成, 张贵宾, 等. 机载激光雷达森林叶面积指数反演研究[J]. 地球物理学报, 2013, 56(5):1467−1475. doi:  10.6038/cjg20130505

Luo S Z, Wang C, Zhang G B, et al. Forest leaf area index (LAI) inversion using airborne LiDAR data[J]. Geophys, 2013, 56(5): 1467−1475. doi:  10.6038/cjg20130505
[6] Chen T, Akciz S O, Hudnut K W, et al. Fault-slip distribution of the 1999 mw 7.1 hector mine earthquake, California, estimated from postearthquake airborne LiDAR data[J]. Bulletin of the Seismological Society of America, 2015, 105: 776−790. doi:  10.1785/0120130108
[7] 黄作维, 刘峰, 胡光伟. 基于多尺度虚拟格网的LiDAR点云数据滤波改进方法[J]. 光学学报, 2017, 37(8):346−355.

Huang Z W, Liu F, Hu G W. Improved method for LiDAR point cloud data filtering based on hierarchical pseudo-grid[J]. Acta Optic Sin, 2017, 37(8): 346−355.
[8] Solberg S. Comparing discrete echoes counts and intensity sums from ALS for estimating forest LAI and gap fraction[C/OL]//International Conference on Silvilaser, Sept. 17−19, 2008: 247−256[2018−05−06]. http://citeseerx.ist.psu.edu/viewdoc/download?doi=
[9] Sithole G, Vosselman G. Experimental comparison of filter algorithms for Bare-Earth extraction from airborne laser scanning point clouds[J]. ISPRS Journal of Photogrammetry & Remote Sensing, 2004, 59: 85−101.
[10] Favorskaya M N, Jain L C. Handbook on advances in remote sensing and geographic information systems[M]. Cham:Springer International Publishing, 2017.
[11] Pingel T J, Clarke K C, Mcbride W A. An improved simple morphological filter for the terrain classification of airborne LiDAR data[J]. ISPRS Journal of Photogrammetry & Remote Sensing, 2013, 77: 21−30.
[12] Zhao X, Guo Q, Su Y, et al. Improved progressive TIN densification filtering algorithm for airborne LiDAR data in forested areas[J]. ISPRS Journal of Photogrammetry & Remote Sensing, 2016, 117: 79−91.
[13] Polat N, Uysal M. Investigating performance of airborne LiDAR data filtering algorithms for DTM generation[J]. Measurement, 2015, 63: 61−68. doi:  10.1016/j.measurement.2014.12.017
[14] Axelsson P. DEM generation from laser scanner data using adaptive TIN models[J]. International Archives of Photogrammetry & Remote Sensing, 2000(33): 110−116.
[15] Zhang K Q, Chen S C, Whitman D, et al. A progressive morphological filter for removing non-ground measurements from airborne LiDAR data[C]. IEEE Transactions on Geoscience and Remote Sensing, 2003 (41): 872−882.
[16] Vosselman G. Slope based filtering of laser altimetry data[C/OL]. Amsterdam: International Archives of Photogrammetry & Remote Sensing, 2000[2018−05−06]. https://www.researchgate.net/publication/228719860_Slope_based_filtering_of_laser_altimetry_data.
[17] Zhao K, García M, Liu S, et al. Terrestrial LiDAR remote sensing of forests: maximum likelihood estimates of canopy profile, leaf area index, and leaf angle distribution[J]. Agricultural & Forest Meteorology, 2015, 209−210: 100−113.
[18] Solberg S, Hill R, Suarez R. Mapping gap fraction, LAI and defoliation using various ALS penetration variables[J]. International Journal of Remote Sensing, 2010, 31(5): 1227−1244. doi:  10.1080/01431160903380672
[19] Morsdorf F, Kötz B, Meier E, et al. Estimation of LAI and fractional cover from small footprint airborne laser scanning data based on gap fraction[J]. Remote Sensing of Environment, 2006, 104(1): 50−61. doi:  10.1016/j.rse.2006.04.019
[20] Hyyppä J, Hyyppä H, Leckie D, et al. Review of methods of small-footprint airborne laser scanning for extracting forest inventory data in boreal forests[J]. International Journal of Remote Sensing, 2008, 29(5): 1339−1366. doi:  10.1080/01431160701736489
[21] Deng S S, Shi W Z. Integration of different filter algorithms for improving the ground surface extraction from airborne LiDAR data[C/OL]. Proceedings of 8th International Symposium on Spatial Data Quality Implementation Science. Hong Kong: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2013, XL-2/W1(2): 105−110[2018−05−06]. http://citeseerx.ist.psu.edu/viewdoc/download?doi=