{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:22:49Z","timestamp":1760242969391,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2015,3,9]],"date-time":"2015-03-09T00:00:00Z","timestamp":1425859200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Full-waveform airborne laser scanning systems provide fundamental observations for each echo, such as the echo width and amplitude. Geometric and physical information about illuminated surfaces are simultaneously provided by a single scanner. However, there are concerns about whether the physical meaning of observations is consistent among different scanning missions. Prior to the application of waveform features for multi-temporal data classification, such features must be normalized. This study investigates the transferability of normalized waveform features to different  surveys. The backscatter coefficient is considered to be a normalized physical feature.  A normalization process for the echo width, which is a geometric feature, is proposed.  The process is based on the coefficient of variation of the echo widths in a defined neighborhood, for which the Fuzzy Small membership function is applied. The normalized features over various land cover types and flight missions are investigated. The effects of different feature combinations on the classification accuracy are analyzed. The overall accuracy of the combination of normalized features and height-based attributes achieves promising results (&gt;93% overall accuracy for ground, roof, low vegetation, and tree canopy) when different flight missions and classifiers are used. Nevertheless, the combination of all possible features, including raw features, normalized features, and height-based features, performs less well and yields inconsistent results.<\/jats:p>","DOI":"10.3390\/rs70302731","type":"journal-article","created":{"date-parts":[[2015,3,9]],"date-time":"2015-03-09T11:47:19Z","timestamp":1425901639000},"page":"2731-2751","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Normalization of Echo Features Derived from Full-Waveform Airborne Laser Scanning Data"],"prefix":"10.3390","volume":"7","author":[{"given":"Yu-Ching","family":"Lin","sequence":"first","affiliation":[{"name":"Department of Environmental Information and Engineering, Chung Cheng Institute of Technology, National Defense University, No.75, Shiyuan Rd., Taoyuan, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2015,3,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.isprsjprs.2004.05.004","article-title":"Experimental comparison of filter algorithms for bare-Earth extraction from airborne laser scanning point clouds","volume":"59","author":"Sithole","year":"2004","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4673","DOI":"10.1080\/01431161.2014.919684","article-title":"Experimental evaluation of ALS point cloud ground extraction tools over different terrain slope and land-cover types","volume":"35","author":"Korzeniowskaa","year":"2014","journal-title":"Int. J. Remote Sens."},{"key":"ref_3","unstructured":"Song, J.-H., Han, S.-H., Yu, K., and Kim, Y.-I. (2002, January 9\u201313). Assessing the possibility of land-cover classification using lidar intensity data. Proceedings of International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Graz, Austria."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/S0924-2716(99)00014-3","article-title":"A comparison between photogrammetry and laser scanning","volume":"54","author":"Baltsavias","year":"1999","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1016\/j.isprsjprs.2007.05.008","article-title":"Correction of laser scanning intensity data: Data and model-driven approaches","volume":"62","author":"Pfeifer","year":"2007","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1016\/j.isprsjprs.2010.05.002","article-title":"Backscatter coefficient as an attribute for the classification of full-waveform airborne laser scanning data in urban areas","volume":"65","author":"Alexander","year":"2010","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"49","DOI":"10.14358\/PERS.76.1.49","article-title":"Factors influencing pulse width of small footprint, full waveform airborne laser scanning data","volume":"76","author":"Lin","year":"2010","journal-title":"Photogram. Eng. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.isprsjprs.2011.12.003","article-title":"Urban vegetation detection using radiometrically calibrated small-footprint full-waveform airborne LiDAR data","volume":"67","author":"Hollaus","year":"2012","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.14358\/PERS.76.9.1051","article-title":"Investigations on surface reflection models for intensity normalization in airborne laser scanning (ALS) data","volume":"76","author":"Jutzi","year":"2010","journal-title":"Photogram. Eng. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2910","DOI":"10.1109\/TGRS.2011.2175232","article-title":"Echo amplitude normalization of full-waveform airborne laser scanning data based on robust incidence angle estimation","volume":"50","author":"Abed","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4505","DOI":"10.3390\/s8084505","article-title":"Object-based point cloud analysis of full-waveform airborne laser scanning data for urban vegetation classification","volume":"8","author":"Rutzinger","year":"2008","journal-title":"Sensors"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.isprsjprs.2010.08.007","article-title":"Relevance of airborne lidar and multispectral image data for urban scene classification using Random Forests","volume":"66","author":"Guo","year":"2011","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_13","unstructured":"Lin, Y.-C., Lin, C.-L., Tsai, M.-D., and Yu, C.-Y. (2013, January 20\u201324). Influence of varying landforms and flight geometry on echo attributes of full-waveform airborne laser scanning data. Proceedings of the 34th Asian Conference on Remote Sensing 2013, Bali, Indonesia."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1989","DOI":"10.1109\/36.851780","article-title":"Decomposition of laser altimeter waveforms","volume":"38","author":"Hofton","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","first-page":"194","article-title":"Measuring and processing the waveform of laser pulses","volume":"1","author":"Jutzi","year":"2005","journal-title":"Opt. 3-D Meas. Tech. VII"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.isprsjprs.2005.12.001","article-title":"Gaussian decomposition and calibration of a novel small-footprint full-waveform digitising airborne laser scanner","volume":"60","author":"Wagner","year":"2006","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_17","unstructured":"Jelalian, A. (1992). Laser Radar Systems, Artech House."},{"key":"ref_18","unstructured":"Ducic, V., Hollaus, M., Ullrich, A., Wagner, W., and Melzer, T. (2006, January 14th\u201315th). 3D vegetation mapping and classification using full-waveform laser scanning. Proceedings of The Workshop on 3D Remote Sensing in Forestry, Vienna, Austria."},{"key":"ref_19","unstructured":"Lehner, H., and Briese, C. (2010, January 5\u20137). Radiometric calibration of full-waveform airborne laser scanning data based on natural surfaces. Proceedings of International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences, Vienna, Austria."},{"key":"ref_20","first-page":"335","article-title":"Radiometric calibration of multi-wavelength airborne laser scanning data","volume":"I-7","author":"Briese","year":"2012","journal-title":"Int. Arch. Photogram. Remote Sens. Spat. Inf. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"505","DOI":"10.1016\/j.isprsjprs.2010.06.007","article-title":"Radiometric calibration of small-footprint airborne laser scanner measurements: Basic phyiscal concepts","volume":"65","author":"Wagner","year":"2010","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_22","unstructured":"Roncat, A., Lehner, H., and Briese, C. (September, January 29). Laser pulse variations and their influence on radiometric calibration of full-waveform laser scanner data. Proceedings of ISPRS Workshop Laser Scanning 2011, Calgary, AB, Canada."},{"key":"ref_23","unstructured":"Jolliffe, I.T. (2002). Principal Component Analysis, Springer."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1038","DOI":"10.3390\/ijgi2041038","article-title":"Georeferenced point clouds: A survey of features and point cloud management","volume":"2","author":"Otepka","year":"2013","journal-title":"ISPRS Int. J. Geo-Inf."},{"key":"ref_25","unstructured":"Weisstein, E.W. Gaussian Function. Available online: http:\/\/mathworld.wolfram.com\/GaussianFunction.html."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1433","DOI":"10.1080\/01431160701736398","article-title":"3D vegetation mapping using small-footprint full-waveform airborne laser scanners","volume":"29","author":"Wagner","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_27","unstructured":"Shan, J., and Toth, C.K. (2009). Topographic Laser Ranging and Scanning: Principles and Processing, Taylor & Francis Group."},{"key":"ref_28","unstructured":"Esri ArcGIS Resources. Available online: http:\/\/resources.arcgis.com\/en\/help\/main\/10.1\/index.html#\/\/009z000000rz000000."},{"key":"ref_29","unstructured":"Riegl Datasheet LMS-Q680i. Available online: http:\/\/www.riegl.com\/uploads\/tx_pxpriegldownloads\/10_DataSheet_LMS-Q680i_28\u201309\u20132012.pdf."},{"key":"ref_30","unstructured":"Jalobeanu, A. (2012, January 19\u201323). The full-waveform lidar RIEGL LMS-Q680i: From reverse Engineering to sensor modeling. Proceedings of ASPRS 2012 Annual Conference, Sacramento, CA, USA."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/3\/2731\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:43:17Z","timestamp":1760215397000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/3\/2731"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,3,9]]},"references-count":30,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2015,3]]}},"alternative-id":["rs70302731"],"URL":"https:\/\/doi.org\/10.3390\/rs70302731","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2015,3,9]]}}}