Closed GoogleCodeExporter closed 9 years ago
can you paste here the first few lines of your xyz lidar file?
Original comment by shrer...@isu.edu
on 18 Dec 2012 at 2:04
here they are:
9.84852438 44.02637693 114.030 30 2
9.84851866 44.02639615 111.400 10 1
9.84852591 44.02640564 116.830 133 2
9.84852695 44.02640887 113.500 82 1
9.84851487 44.02641940 115.100 92 2
9.84851131 44.02641475 117.340 128 2
9.84849768 44.02641233 114.930 77 2
9.84851168 44.02642267 117.040 61 2
9.84852530 44.02643274 119.000 128 2
9.84852042 44.02644988 119.340 87 2
Original comment by f.pogg...@gmail.com
on 18 Dec 2012 at 2:14
It looks like your XY are in degrees. When converting, in the "Ascii to LAS"
conversion window, you have to change the projection from 'Arbitrary' to
'Geographic Long/Lat'. This will ensure that proper header scaling are applied.
I tested it with your data and it works!
Original comment by shrer...@isu.edu
on 18 Dec 2012 at 6:27
Ok. Following your kind suggestion things got a little better but still it
doesn't work properly. Now the 3D Lidar viewer does open the file but what
I get is a vertical line of points: I desume that there's still some
trouble with the x-y coordinates of the point cloud. Reading the las header
file, I notice that there's a strange x and y scaling (1.0e-7). I then
tried to reproject the las file into planar coordinates (UTM-WGS84 Zone
32N): the converted file is now properly visualized! Nevertheless, it would
be useful not to be forced to convert the files into planar coordinates....
Original comment by f.pogg...@gmail.com
on 19 Dec 2012 at 9:00
Strange! I will look into it further. 1.0e-7 in the header is 0.0000001 which
is the number of decimal places. You might also want to try ENVI's native Lidar
visualization in ENVI 4.8 (32-bit) (File>Open External File>Las LiDAR>3D LiDAR
Viewer).
Original comment by shrer...@isu.edu
on 19 Dec 2012 at 2:01
Version 1.5.0 has been released that allows you to manually specify scale and
offsets during ascii to LAS conversions. This should take care of the issues.
Remember, LAS format holds XYZ data in
[http://www.exelisvis.com/docs/IDL_Data_Types.html long format]. If, after
scaling, you have more digits than the format accommodates, you will need to
apply proper offsets.
Original comment by shrer...@isu.edu
on 20 Dec 2012 at 9:18
Original comment by shrer...@isu.edu
on 4 Mar 2013 at 7:06
Original issue reported on code.google.com by
f.pogg...@gmail.com
on 18 Dec 2012 at 1:28