Places

Show Only ...
Maps - Photos - Videos

Creating Digital Surface Models GeoTIFF Using National Map Downloader, LiDAR Point Clouds and PDAL 🗺

|

Find LiDAR Point Clouds on the National Map Downloader: https://apps.nationalmap.gov/downloader/#/

Select Find Elevation Source Data (3DEP) – Lidar, IfSAR

Search for LiDAR Point Cloud (LPC)

Click Export all results as a TXT file and save to a directory.

Then run this Unix command on the text file to download point clouds:

cat data.txt | tr -d '\n' | xargs -d '\r' -I {} wget -c -nc '{}'

Next create a pipeline.txt for pdal with the classification (For DSM, 1 are unclassified points like buildings and treetops, while 2 are ground points, if you want a DEM, you can also make them this way too with Classification of 2:2):

{ 
    "pipeline": [
        { 
            "type": "readers.las"
        },
        {
            "type": "filters.range",
            "limits": "Classification[1:1]"
        },
        {
            "gdaldriver":"GTiff",
            "resolution": 1.0,
            "output_type": "max",
            "type":"writers.gdal"
        }
    ]
}

Next convert the point clouds into digital surface model (GeoTIFF), you can use this shell command with xargs to go over each LAS file, using the above pipeline:

ls *.laz | xargs -I {} basename {} .laz | xargs -P3 -I {} pdal pipeline pipeline.txt --readers.las.filename={}.laz --writers.gdal.filename={}.tif

The above command can be somewhat slow depending on how many LAZ point clouds you need to go through and your selected resolution. -P3 sets the number of parallel process (3) which can help speed things up a bit.

Now we have the digital surface models raster that can be used in QGIS for hillshade for 3D.

Build a virtual raster (dsm.vrt) for easy loading into QGIS rather than loading separate files.

gdalbuildvrt dsm.vrt *.tif

US 9 Suffixes

|

NY 9N is the longest at 143 miles, with US 9W being 131 miles (within New York though if you include New Jersey section it's 142 miles). NY 9R is the shortest at a little over 3 miles.

Untitled [Expires June 25 2025]

Miles from nowhere 🌲🏘️

|

One of the problems I face with finding a home is the life I love is literally miles from nowhere. I spend so much time wilderness camping where often the nearest house is five miles or further away – and sometimes further. Usually the same is true with other campsites – miles away.

There is just very few places anywhere near the city that is like the life I spend up in the wilderness. Places where I can burn stuff and shoot as much as my heart desires without any neighbors nearby. Where I don’t have to think about how much noise or smoke I create.

It just seems like every house and land you look at is nearby another house, anywhere near the city. Maybe country lots are slightly larger than your typical suburban and urban lot but not by much. There is some half decent places but they’re all on the border of too far to reasonably commute on a daily basis.

The truth is that I need to look west where there is more land and things are more spread out. But that is going to take a complete reboot of my life, starting from scratch and that isn’t easy either. And it’s damn scary too.