Changes between Version 1 and Version 2 of Processing/LidarNoisyPoints
- Timestamp:
- Feb 21, 2012, 5:27:15 PM (13 years ago)
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Processing/LidarNoisyPoints
v1 v2 1 1 = Post Processing LiDAR Point Clouds= 2 2 3 The usual form of delivery of the processed LiDAR data is in the form of a point cloud. This takes one of two forms; [link ASCII text files] or [http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html binary LAS] files. As part of the standard processing and quality checking of the LiDAR point clouds, ARSF-DAN classify 'noisy' points. This is done both by using automatic algorithms and by viewing the data. The noisy points can be one of the following: 3 The usual form of delivery of the processed LiDAR data is in the form of a point cloud. This takes one of two forms; [link ASCII text files] or binary [http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html LAS] files. The point clouds contain all the LiDAR data as vectors, a list of individual points, rather than as rasterised data. 4 5 == Removing Noise Points == 6 7 As part of the standard processing and quality checking of the LiDAR point clouds, ARSF-DAN classify 'noisy' points. This is done both by using automatic algorithms and by viewing the data. The noisy points can be one of the following: 4 8 5 9 * isolated points … … 9 13 * system noise 10 14 11 It is advised that these points be removed before using the data, unless they are of specific use to your studies.15 When a point has been identified as being 'noise' it is given a classification value of '7'. All other points will probably have classification of '0' (unclassified) or '1' (default). The classification values used follow the ASPRS standard LiDAR point classes. 12 16 13 == Removing Noise Points == 17 It is advised that these points be removed before using the data, unless they are of specific use to your studies. ARSF-DAN included a utility for removing these points from the ASCII files called 'pt_cloud_filter'. To remove them from LAS files it is suggested to download the LASTools package, specifically the las2las tool. 14 18 15 When a point has been identified as being 'noise' it is given a classification value of '7'. 19 === Removing noisy points from ASCII files === 20 21 22 === Removing noisy points from LAS files ===