Problem computing grid metrics over a relatively very large area

[Collins BK]

Hey Martin,

 

I have encountered a frustrating error while computing grid metrics over a very large area.

The details of the error can be seen in the attached image.

 

I am using the following syntax;

 

set PATH=%PATH%;C:\LAStools\bin;

 

:: here we specify the input (Normalized LiDAR data in .laz format)

set NORMALIZED=Z:\data\edit\LiDAR\2015\hai\Normalized\*.laz

 

:: here we specify the output (Compressed retiled, normalized LiDAR data in .laz format)

set OUTPUT=Z:\data\edit\LiDAR\2015\hai\Metrics\Metrics_test.csv

 

 

lascanopy            -i %NORMALIZED% ^

                                                -merged ^

                                                -step 100 ^

                                                -p 5 10 25 50 75 90 -avg -std -ske -kur -qav -b 5 10 25 50 75 90 -height_cutoff 0 -clamp_z_below 0.0 -cov -dns -gap -int_max -int_avg -int_qav -int_std -int_ske -int_kur -int_p 5 10 25 50 75 90 -c 0.5 2 4 10 50 -d 0.5 2 4 10 50 ^

                                                -o %OUTPUT% ^

                                                -centroids ^

                                                -cores 16

 

Any ideas? I would like to output a .csv file for further modelling.

 

Your support is very much appreciated.

Collins 

[Martin Isenburg]

Hello Collins,

Simple: too many points in the merged file. But i should be catching this error a little better and let the tool tell you what the issue really is ... (-:

Here are the possible workflows. If your input is already in tiles whose size is some multiple of 100 then simply run:

lascanopy  -i  normalized_tiles\*.laz ^
                     -clamp_z_below 0.0 ^
                     -height_cutoff 0 ^
                     -step 100 ^
                     -p 5 10 25 50 75 90 ^
                     -avg -std -ske -kur -qav ^
                     -b 5 10 25 50 75 90 ^
                     -cov -dns -gap ^
                     -int_max -int_avg -int_qav ^
                     -int_std -int_ske -int_kur ^
                     -int_p 5 10 25 50 75 90 ^
                     -c 0.5 2 4 10 50 ^

                     -d 0.5 2 4 10 50 ^

                     -centroids ^
                     -odir metrics -ocsv ^
                     -cores 16

This generates one CSV file per tile. I am sure there is a tool to merge CSV files, is there not?

If your normalised input is not tiled yet simply run in an earlier step:

lastile  -i normalized\*.laz -merged ^
             -tile_size 2000 ^
             -odir normalized_tiles -olaz

Regards,

Martin @rapidlasso

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