[pdal] Z value change on reprojection in pdal 1.6

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[pdal] Z value change on reprojection in pdal 1.6

Doug Newcomb
Ok,
Finally diving into pdal more deeply.  I installed the docker  instance of pdal 1.6 and tried a bit of command line reprojection:

I downloaded some data from the NOAA website and  re-projected from Decimal Degrees to Albers Meters Conus ( EPSG:5070) 
pdal translate /data/20100503_LAS_S23_1836_10.laz /data/albers_20100503_LAS_S23_1836_10.laz -f filters.reprojection  --filters.reprojection.out_srs="EPSG:5070"

 For the input data , lasinfo gives :


  Minimum and Maximum Attributes (min,max)
---------------------------------------------------------
  Min X, Y, Z: -76.2571767, 37.9028129, 0.024
  Max X, Y, Z: -76.2527221, 37.9068695, 29.966
  Bounding Box: -76.2571767, 37.9028129, -76.2527221, 37.9068695

for the output laz file, lasinfo gives:

  Minimum and Maximum Attributes (min,max)
---------------------------------------------------------
  Min X, Y, Z: 1707096.44, 1829911.69, -35.72
  Max X, Y, Z: 1707557.20, 1830350.12, -5.77
  Bounding Box: 1707096.44, 1829911.69, 1707557.20, 1830350.12


pdal info for the input file gives:


{
  "filename": "\/data\/20100503_LAS_S23_1836_10.laz",
  "pdal_version": "1.6.0 (git-version: 94ad83)",
  "stats":
  {
    "bbox":
    {
      "EPSG:4326":
      {
        "bbox":
        {
          "maxx": -76.2527221,
          "maxy": 37.9068695,
          "maxz": -5.777103023,
          "minx": -76.2571767,
          "miny": 37.9028129,
          "minz": -35.71281856
        },
        "boundary": {
   "coordinates" : [
      [
         [ -76.257176700000002, 37.902812900000001 ],
         [ -76.257176700000002, 37.906869499999999 ],
         [ -76.2527221, 37.906869499999999 ],
         [ -76.2527221, 37.902812900000001 ],
         [ -76.257176700000002, 37.902812900000001 ]
      ]
   ],
   "type" : "Polygon"
}

      },
      "native":
      {
        "bbox":
        {
          "maxx": -76.2527221,
          "maxy": 37.9068695,
          "maxz": 29.966,
          "minx": -76.2571767,
          "miny": 37.9028129,
          "minz": 0.024
        },
        "boundary": {

pdal info on the output laz file gives:
{
  "filename": "\/data\/albers_20100503_LAS_S23_1836_10.laz",
  "pdal_version": "1.6.0 (git-version: 94ad83)",
  "stats":
  {
    "bbox":
    {
      "EPSG:4326":
      {
        "bbox":
        {
          "maxx": -76.25185156,
          "maxy": 37.90686951,
          "maxz": -5.77,
          "minx": -76.25806657,
          "miny": 37.9021939,
          "minz": -35.72
        },
        "boundary": {
   "coordinates" : [
      [
         [ -76.258066569999997, 37.903041880000004 ],
         [ -76.257028300000002, 37.90686951 ],
         [ -76.251851560000006, 37.90602148 ],
         [ -76.252890100000002, 37.9021939 ],
         [ -76.258066569999997, 37.903041880000004 ]
      ]
   ],
   "type" : "Polygon"
}

      },
      "native":
      {
        "bbox":
        {
          "maxx": 1707557.2,
          "maxy": 1830350.12,
          "maxz": -5.77,
          "minx": 1707096.44,
          "miny": 1829911.69,
          "minz": -35.72
        },
        "boundary": {


Am I missing a switch in the translate command?


Doug



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Re: [pdal] Z value change on reprojection in pdal 1.6

Michael Smith

Doug,

 

It looks like perhaps the header metadata is not correct, which is what I think you are seeing from lasinfo. When you inspected the Decimal Degrees file it shows

 

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

 

which match your albers output.

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: pdal <[hidden email]> on behalf of Doug Newcomb <[hidden email]>
Date: Monday, November 13, 2017 at 8:14 PM
To: pdal <[hidden email]>
Subject: [pdal] Z value change on reprojection in pdal 1.6

 

Ok,

Finally diving into pdal more deeply.  I installed the docker  instance of pdal 1.6 and tried a bit of command line reprojection:

 

I downloaded some data from the NOAA website and  re-projected from Decimal Degrees to Albers Meters Conus ( EPSG:5070) 

pdal translate /data/20100503_LAS_S23_1836_10.laz /data/albers_20100503_LAS_S23_1836_10.laz -f filters.reprojection  --filters.reprojection.out_srs="EPSG:5070"

 

 For the input data , lasinfo gives :

 

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         -76.2571767, 37.9028129, 0.024

  Max X, Y, Z:                        -76.2527221, 37.9068695, 29.966

  Bounding Box:                   -76.2571767, 37.9028129, -76.2527221, 37.9068695

 

for the output laz file, lasinfo gives:

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         1707096.44, 1829911.69, -35.72

  Max X, Y, Z:                        1707557.20, 1830350.12, -5.77

  Bounding Box:                   1707096.44, 1829911.69, 1707557.20, 1830350.12

 

 

pdal info for the input file gives:

 

 

{

  "filename": "\/data\/20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.257176700000002, 37.902812900000001 ],

         [ -76.257176700000002, 37.906869499999999 ],

         [ -76.2527221, 37.906869499999999 ],

         [ -76.2527221, 37.902812900000001 ],

         [ -76.257176700000002, 37.902812900000001 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": 29.966,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": 0.024

        },

        "boundary": {

 

pdal info on the output laz file gives:

{

  "filename": "\/data\/albers_20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.25185156,

          "maxy": 37.90686951,

          "maxz": -5.77,

          "minx": -76.25806657,

          "miny": 37.9021939,

          "minz": -35.72

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.258066569999997, 37.903041880000004 ],

         [ -76.257028300000002, 37.90686951 ],

         [ -76.251851560000006, 37.90602148 ],

         [ -76.252890100000002, 37.9021939 ],

         [ -76.258066569999997, 37.903041880000004 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": 1707557.2,

          "maxy": 1830350.12,

          "maxz": -5.77,

          "minx": 1707096.44,

          "miny": 1829911.69,

          "minz": -35.72

        },

        "boundary": {

 

 

Am I missing a switch in the translate command?

 

 

Doug

 

 

_______________________________________________ pdal mailing list [hidden email] https://lists.osgeo.org/mailman/listinfo/pdal


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Re: [pdal] Z value change on reprojection in pdal 1.6

Doug Newcomb
Micheal,
The problem is the z values of all of the point values are have been changed.    I had created a raster from the mean value of the ground points from the pdal reprojected data.  I then went back to NOAA's site and selected a small subset to compare and had their engine deliver the points in Albers Meters Conus   NAVD88.  I imported the points to create a raster in the same way and then subtraced the Z value of the pdal reprojected points from the NOAA reprojected points.  The height values vary by 32-36 m ( see below) .

That was why I was asking if I had missed a step that ensured that the Z values stayed at the Geoid12A/12B/NAVD88 values.

Tue Nov 14 09:45:55 2017)                                                      
r.info map=noaa_pdal_vert_diff_m@dnewcomb                                       
 +----------------------------------------------------------------------------+
 | Map:      noaa_pdal_vert_diff_m@dnewcom  Date: Tue Nov 14 09:36:19 2017    |
 | Mapset:   dnewcomb                       Login of Creator: dnewcomb        |
 | Location: seva_albers                                                      |
 | DataBase: /data2/grass70_data                                              |
 | Title:    noaa_pdal_vert_diff_m                                            |
 | Timestamp: none                                                            |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster               Number of Categories: 0               |
 |   Data Type:    FCELL                                                      |
 |   Rows:         12465                                                      |
 |   Columns:      20411                                                      |
 |   Total Cells:  254423115                                                  |
 |        Projection: NAD83 / Conus Albers                                    |
 |            N: 1687158.47979    S: 1668162.01936   Res: 1.52398399          |
 |            E: 1653024.11274    W: 1621917.96408   Res: 1.52398945          |
 |   Range of data:    min = 32.17395  max = 36.06071                         |
 |                                                                            |
 |   Data Description:                                                        |
 |    generated by r.mapcalc                                                  |
 |                                                                            |
 |   Comments:                                                                |
 |    2635_mean_ground_1_524_test_from_noaa_meters@dnewcomb -                 |
 |    2635_mean_ground_1_524@PERMANENT                                        |
 |                                                                            |
 +----------------------------------------------------------------------------+



Doug

On Mon, Nov 13, 2017 at 8:20 PM, Michael Smith <[hidden email]> wrote:

Doug,

 

It looks like perhaps the header metadata is not correct, which is what I think you are seeing from lasinfo. When you inspected the Decimal Degrees file it shows

 

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

 

which match your albers output.

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: pdal <[hidden email]> on behalf of Doug Newcomb <[hidden email]>
Date: Monday, November 13, 2017 at 8:14 PM
To: pdal <[hidden email]>
Subject: [pdal] Z value change on reprojection in pdal 1.6

 

Ok,

Finally diving into pdal more deeply.  I installed the docker  instance of pdal 1.6 and tried a bit of command line reprojection:

 

I downloaded some data from the NOAA website and  re-projected from Decimal Degrees to Albers Meters Conus ( EPSG:5070) 

pdal translate /data/20100503_LAS_S23_1836_10.laz /data/albers_20100503_LAS_S23_1836_10.laz -f filters.reprojection  --filters.reprojection.out_srs="EPSG:5070"

 

 For the input data , lasinfo gives :

 

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         -76.2571767, 37.9028129, 0.024

  Max X, Y, Z:                        -76.2527221, 37.9068695, 29.966

  Bounding Box:                   -76.2571767, 37.9028129, -76.2527221, 37.9068695

 

for the output laz file, lasinfo gives:

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         1707096.44, 1829911.69, -35.72

  Max X, Y, Z:                        1707557.20, 1830350.12, -5.77

  Bounding Box:                   1707096.44, 1829911.69, 1707557.20, 1830350.12

 

 

pdal info for the input file gives:

 

 

{

  "filename": "\/data\/20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.257176700000002, 37.902812900000001 ],

         [ -76.257176700000002, 37.906869499999999 ],

         [ -76.2527221, 37.906869499999999 ],

         [ -76.2527221, 37.902812900000001 ],

         [ -76.257176700000002, 37.902812900000001 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": 29.966,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": 0.024

        },

        "boundary": {

 

pdal info on the output laz file gives:

{

  "filename": "\/data\/albers_20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.25185156,

          "maxy": 37.90686951,

          "maxz": -5.77,

          "minx": -76.25806657,

          "miny": 37.9021939,

          "minz": -35.72

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.258066569999997, 37.903041880000004 ],

         [ -76.257028300000002, 37.90686951 ],

         [ -76.251851560000006, 37.90602148 ],

         [ -76.252890100000002, 37.9021939 ],

         [ -76.258066569999997, 37.903041880000004 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": 1707557.2,

          "maxy": 1830350.12,

          "maxz": -5.77,

          "minx": 1707096.44,

          "miny": 1829911.69,

          "minz": -35.72

        },

        "boundary": {

 

 

Am I missing a switch in the translate command?

 

 

Doug

 

 

_______________________________________________ pdal mailing list [hidden email] https://lists.osgeo.org/mailman/listinfo/pdal



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Re: [pdal] Z value change on reprojection in pdal 1.6

Michael Smith

Hmm, it might be that pdal is reading the source vertical projection as navd88 and if you are reprojecting and not specifying a vertical projection, it might be assuming wgs84. You can try specifying the output projection as epsg:5070+5703

 

Mike

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: Doug Newcomb <[hidden email]>
Date: Tuesday, November 14, 2017 at 9:58 AM
To: Michael Smith <[hidden email]>
Cc: pdal <[hidden email]>
Subject: Re: [pdal] Z value change on reprojection in pdal 1.6

 

Micheal,

The problem is the z values of all of the point values are have been changed.    I had created a raster from the mean value of the ground points from the pdal reprojected data.  I then went back to NOAA's site and selected a small subset to compare and had their engine deliver the points in Albers Meters Conus   NAVD88.  I imported the points to create a raster in the same way and then subtraced the Z value of the pdal reprojected points from the NOAA reprojected points.  The height values vary by 32-36 m ( see below) .

 

That was why I was asking if I had missed a step that ensured that the Z values stayed at the Geoid12A/12B/NAVD88 values.

 

Tue Nov 14 09:45:55 2017)                                                      

r.info map=noaa_pdal_vert_diff_m@dnewcomb                                       

 +----------------------------------------------------------------------------+

 | Map:      noaa_pdal_vert_diff_m@dnewcom  Date: Tue Nov 14 09:36:19 2017    |

 | Mapset:   dnewcomb                       Login of Creator: dnewcomb        |

 | Location: seva_albers                                                      |

 | DataBase: /data2/grass70_data                                              |

 | Title:    noaa_pdal_vert_diff_m                                            |

 | Timestamp: none                                                            |

 |----------------------------------------------------------------------------|

 |                                                                            |

 |   Type of Map:  raster               Number of Categories: 0               |

 |   Data Type:    FCELL                                                      |

 |   Rows:         12465                                                      |

 |   Columns:      20411                                                      |

 |   Total Cells:  254423115                                                  |

 |        Projection: NAD83 / Conus Albers                                    |

 |            N: 1687158.47979    S: 1668162.01936   Res: 1.52398399          |

 |            E: 1653024.11274    W: 1621917.96408   Res: 1.52398945          |

 |   Range of data:    min = 32.17395  max = 36.06071                         |

 |                                                                            |

 |   Data Description:                                                        |

 |    generated by r.mapcalc                                                  |

 |                                                                            |

 |   Comments:                                                                |

 |    2635_mean_ground_1_524_test_from_noaa_meters@dnewcomb -                 |

 |    2635_mean_ground_1_524@PERMANENT                                        |

 |                                                                            |

 +----------------------------------------------------------------------------+

 

 

 

Doug

 

On Mon, Nov 13, 2017 at 8:20 PM, Michael Smith <[hidden email]> wrote:

Doug,

 

It looks like perhaps the header metadata is not correct, which is what I think you are seeing from lasinfo. When you inspected the Decimal Degrees file it shows

 

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

 

which match your albers output.

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: pdal <[hidden email]> on behalf of Doug Newcomb <[hidden email]>
Date: Monday, November 13, 2017 at 8:14 PM
To: pdal <[hidden email]>
Subject: [pdal] Z value change on reprojection in pdal 1.6

 

Ok,

Finally diving into pdal more deeply.  I installed the docker  instance of pdal 1.6 and tried a bit of command line reprojection:

 

I downloaded some data from the NOAA website and  re-projected from Decimal Degrees to Albers Meters Conus ( EPSG:5070) 

pdal translate /data/20100503_LAS_S23_1836_10.laz /data/albers_20100503_LAS_S23_1836_10.laz -f filters.reprojection  --filters.reprojection.out_srs="EPSG:5070"

 

 For the input data , lasinfo gives :

 

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         -76.2571767, 37.9028129, 0.024

  Max X, Y, Z:                        -76.2527221, 37.9068695, 29.966

  Bounding Box:                   -76.2571767, 37.9028129, -76.2527221, 37.9068695

 

for the output laz file, lasinfo gives:

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         1707096.44, 1829911.69, -35.72

  Max X, Y, Z:                        1707557.20, 1830350.12, -5.77

  Bounding Box:                   1707096.44, 1829911.69, 1707557.20, 1830350.12

 

 

pdal info for the input file gives:

 

 

{

  "filename": "\/data\/20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.257176700000002, 37.902812900000001 ],

         [ -76.257176700000002, 37.906869499999999 ],

         [ -76.2527221, 37.906869499999999 ],

         [ -76.2527221, 37.902812900000001 ],

         [ -76.257176700000002, 37.902812900000001 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": 29.966,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": 0.024

        },

        "boundary": {

 

pdal info on the output laz file gives:

{

  "filename": "\/data\/albers_20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.25185156,

          "maxy": 37.90686951,

          "maxz": -5.77,

          "minx": -76.25806657,

          "miny": 37.9021939,

          "minz": -35.72

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.258066569999997, 37.903041880000004 ],

         [ -76.257028300000002, 37.90686951 ],

         [ -76.251851560000006, 37.90602148 ],

         [ -76.252890100000002, 37.9021939 ],

         [ -76.258066569999997, 37.903041880000004 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": 1707557.2,

          "maxy": 1830350.12,

          "maxz": -5.77,

          "minx": 1707096.44,

          "miny": 1829911.69,

          "minz": -35.72

        },

        "boundary": {

 

 

Am I missing a switch in the translate command?

 

 

Doug

 

 

_______________________________________________ pdal mailing list [hidden email] https://lists.osgeo.org/mailman/listinfo/pdal

 


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Re: [pdal] Z value change on reprojection in pdal 1.6

Smith, Michael ERDC-RDE-CRREL-NH
In reply to this post by Doug Newcomb

Hmm, it might be that pdal is reading the source vertical projection as navd88 and if you are reprojecting and not specifying a vertical projection, it might be assuming wgs84. You can try specifying the output projection as epsg:5070+5703

 

Mike

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: Doug Newcomb <[hidden email]>
Date: Tuesday, November 14, 2017 at 9:58 AM
To: Michael Smith <[hidden email]>
Cc: pdal <[hidden email]>
Subject: Re: [pdal] Z value change on reprojection in pdal 1.6

 

Micheal,

The problem is the z values of all of the point values are have been changed.    I had created a raster from the mean value of the ground points from the pdal reprojected data.  I then went back to NOAA's site and selected a small subset to compare and had their engine deliver the points in Albers Meters Conus   NAVD88.  I imported the points to create a raster in the same way and then subtraced the Z value of the pdal reprojected points from the NOAA reprojected points.  The height values vary by 32-36 m ( see below) .

 

That was why I was asking if I had missed a step that ensured that the Z values stayed at the Geoid12A/12B/NAVD88 values.

 

Tue Nov 14 09:45:55 2017)                                                      

r.info map=noaa_pdal_vert_diff_m@dnewcomb                                       

 +----------------------------------------------------------------------------+

 | Map:      noaa_pdal_vert_diff_m@dnewcom  Date: Tue Nov 14 09:36:19 2017    |

 | Mapset:   dnewcomb                       Login of Creator: dnewcomb        |

 | Location: seva_albers                                                      |

 | DataBase: /data2/grass70_data                                              |

 | Title:    noaa_pdal_vert_diff_m                                            |

 | Timestamp: none                                                            |

 |----------------------------------------------------------------------------|

 |                                                                            |

 |   Type of Map:  raster               Number of Categories: 0               |

 |   Data Type:    FCELL                                                      |

 |   Rows:         12465                                                      |

 |   Columns:      20411                                                      |

 |   Total Cells:  254423115                                                  |

 |        Projection: NAD83 / Conus Albers                                    |

 |            N: 1687158.47979    S: 1668162.01936   Res: 1.52398399          |

 |            E: 1653024.11274    W: 1621917.96408   Res: 1.52398945          |

 |   Range of data:    min = 32.17395  max = 36.06071                         |

 |                                                                            |

 |   Data Description:                                                        |

 |    generated by r.mapcalc                                                  |

 |                                                                            |

 |   Comments:                                                                |

 |    2635_mean_ground_1_524_test_from_noaa_meters@dnewcomb -                 |

 |    2635_mean_ground_1_524@PERMANENT                                        |

 |                                                                            |

 +----------------------------------------------------------------------------+

 

 

 

Doug

 

On Mon, Nov 13, 2017 at 8:20 PM, Michael Smith <[hidden email]> wrote:

Doug,

 

It looks like perhaps the header metadata is not correct, which is what I think you are seeing from lasinfo. When you inspected the Decimal Degrees file it shows

 

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

 

which match your albers output.

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: pdal <[hidden email]> on behalf of Doug Newcomb <[hidden email]>
Date: Monday, November 13, 2017 at 8:14 PM
To: pdal <[hidden email]>
Subject: [pdal] Z value change on reprojection in pdal 1.6

 

Ok,

Finally diving into pdal more deeply.  I installed the docker  instance of pdal 1.6 and tried a bit of command line reprojection:

 

I downloaded some data from the NOAA website and  re-projected from Decimal Degrees to Albers Meters Conus ( EPSG:5070) 

pdal translate /data/20100503_LAS_S23_1836_10.laz /data/albers_20100503_LAS_S23_1836_10.laz -f filters.reprojection  --filters.reprojection.out_srs="EPSG:5070"

 

 For the input data , lasinfo gives :

 

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         -76.2571767, 37.9028129, 0.024

  Max X, Y, Z:                        -76.2527221, 37.9068695, 29.966

  Bounding Box:                   -76.2571767, 37.9028129, -76.2527221, 37.9068695

 

for the output laz file, lasinfo gives:

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         1707096.44, 1829911.69, -35.72

  Max X, Y, Z:                        1707557.20, 1830350.12, -5.77

  Bounding Box:                   1707096.44, 1829911.69, 1707557.20, 1830350.12

 

 

pdal info for the input file gives:

 

 

{

  "filename": "\/data\/20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.257176700000002, 37.902812900000001 ],

         [ -76.257176700000002, 37.906869499999999 ],

         [ -76.2527221, 37.906869499999999 ],

         [ -76.2527221, 37.902812900000001 ],

         [ -76.257176700000002, 37.902812900000001 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": 29.966,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": 0.024

        },

        "boundary": {

 

pdal info on the output laz file gives:

{

  "filename": "\/data\/albers_20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.25185156,

          "maxy": 37.90686951,

          "maxz": -5.77,

          "minx": -76.25806657,

          "miny": 37.9021939,

          "minz": -35.72

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.258066569999997, 37.903041880000004 ],

         [ -76.257028300000002, 37.90686951 ],

         [ -76.251851560000006, 37.90602148 ],

         [ -76.252890100000002, 37.9021939 ],

         [ -76.258066569999997, 37.903041880000004 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": 1707557.2,

          "maxy": 1830350.12,

          "maxz": -5.77,

          "minx": 1707096.44,

          "miny": 1829911.69,

          "minz": -35.72

        },

        "boundary": {

 

 

Am I missing a switch in the translate command?

 

 

Doug

 

 

_______________________________________________ pdal mailing list [hidden email] https://lists.osgeo.org/mailman/listinfo/pdal

 


_______________________________________________
pdal mailing list
[hidden email]
https://lists.osgeo.org/mailman/listinfo/pdal
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Re: [pdal] Z value change on reprojection in pdal 1.6

Doug Newcomb
Michael,
That seems to have done the trick!  I will test against the batch from NOAA later, but I think that looks like the issue.  So this version of pdal is not keeping the vertical datum by default when reprojecting, and you need to specify the vertical datum in the projection definition.  I can understand why that might be, but I was assuming that the vertical datum would carry over by default.

Doug

On Tue, Nov 14, 2017 at 10:07 AM, Smith, Michael ERDC-RDE-CRREL-NH CIV <[hidden email]> wrote:

Hmm, it might be that pdal is reading the source vertical projection as navd88 and if you are reprojecting and not specifying a vertical projection, it might be assuming wgs84. You can try specifying the output projection as epsg:5070+5703

 

Mike

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: Doug Newcomb <[hidden email]>
Date: Tuesday, November 14, 2017 at 9:58 AM
To: Michael Smith <[hidden email]>
Cc: pdal <[hidden email]>
Subject: Re: [pdal] Z value change on reprojection in pdal 1.6

 

Micheal,

The problem is the z values of all of the point values are have been changed.    I had created a raster from the mean value of the ground points from the pdal reprojected data.  I then went back to NOAA's site and selected a small subset to compare and had their engine deliver the points in Albers Meters Conus   NAVD88.  I imported the points to create a raster in the same way and then subtraced the Z value of the pdal reprojected points from the NOAA reprojected points.  The height values vary by 32-36 m ( see below) .

 

That was why I was asking if I had missed a step that ensured that the Z values stayed at the Geoid12A/12B/NAVD88 values.

 

Tue Nov 14 09:45:55 2017)                                                      

r.info map=noaa_pdal_vert_diff_m@dnewcomb                                       

 +----------------------------------------------------------------------------+

 | Map:      noaa_pdal_vert_diff_m@dnewcom  Date: Tue Nov 14 09:36:19 2017    |

 | Mapset:   dnewcomb                       Login of Creator: dnewcomb        |

 | Location: seva_albers                                                      |

 | DataBase: /data2/grass70_data                                              |

 | Title:    noaa_pdal_vert_diff_m                                            |

 | Timestamp: none                                                            |

 |----------------------------------------------------------------------------|

 |                                                                            |

 |   Type of Map:  raster               Number of Categories: 0               |

 |   Data Type:    FCELL                                                      |

 |   Rows:         12465                                                      |

 |   Columns:      20411                                                      |

 |   Total Cells:  254423115                                                  |

 |        Projection: NAD83 / Conus Albers                                    |

 |            N: 1687158.47979    S: 1668162.01936   Res: 1.52398399          |

 |            E: 1653024.11274    W: 1621917.96408   Res: 1.52398945          |

 |   Range of data:    min = 32.17395  max = 36.06071                         |

 |                                                                            |

 |   Data Description:                                                        |

 |    generated by r.mapcalc                                                  |

 |                                                                            |

 |   Comments:                                                                |

 |    2635_mean_ground_1_524_test_from_noaa_meters@dnewcomb -                 |

 |    2635_mean_ground_1_524@PERMANENT                                        |

 |                                                                            |

 +----------------------------------------------------------------------------+

 

 

 

Doug

 

On Mon, Nov 13, 2017 at 8:20 PM, Michael Smith <[hidden email]> wrote:

Doug,

 

It looks like perhaps the header metadata is not correct, which is what I think you are seeing from lasinfo. When you inspected the Decimal Degrees file it shows

 

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

 

which match your albers output.

 

 

-- 

Michael Smith

Remote Sensing/GIS Center

US Army Corps of Engineers

 

 

From: pdal <[hidden email]> on behalf of Doug Newcomb <[hidden email]>
Date: Monday, November 13, 2017 at 8:14 PM
To: pdal <[hidden email]>
Subject: [pdal] Z value change on reprojection in pdal 1.6

 

Ok,

Finally diving into pdal more deeply.  I installed the docker  instance of pdal 1.6 and tried a bit of command line reprojection:

 

I downloaded some data from the NOAA website and  re-projected from Decimal Degrees to Albers Meters Conus ( EPSG:5070) 

pdal translate /data/20100503_LAS_S23_1836_10.laz /data/albers_20100503_LAS_S23_1836_10.laz -f filters.reprojection  --filters.reprojection.out_srs="EPSG:5070"

 

 For the input data , lasinfo gives :

 

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         -76.2571767, 37.9028129, 0.024

  Max X, Y, Z:                        -76.2527221, 37.9068695, 29.966

  Bounding Box:                   -76.2571767, 37.9028129, -76.2527221, 37.9068695

 

for the output laz file, lasinfo gives:

 

  Minimum and Maximum Attributes (min,max)

---------------------------------------------------------

  Min X, Y, Z:                         1707096.44, 1829911.69, -35.72

  Max X, Y, Z:                        1707557.20, 1830350.12, -5.77

  Bounding Box:                   1707096.44, 1829911.69, 1707557.20, 1830350.12

 

 

pdal info for the input file gives:

 

 

{

  "filename": "\/data\/20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": -5.777103023,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": -35.71281856

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.257176700000002, 37.902812900000001 ],

         [ -76.257176700000002, 37.906869499999999 ],

         [ -76.2527221, 37.906869499999999 ],

         [ -76.2527221, 37.902812900000001 ],

         [ -76.257176700000002, 37.902812900000001 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": -76.2527221,

          "maxy": 37.9068695,

          "maxz": 29.966,

          "minx": -76.2571767,

          "miny": 37.9028129,

          "minz": 0.024

        },

        "boundary": {

 

pdal info on the output laz file gives:

{

  "filename": "\/data\/albers_20100503_LAS_S23_1836_10.laz",

  "pdal_version": "1.6.0 (git-version: 94ad83)",

  "stats":

  {

    "bbox":

    {

      "EPSG:4326":

      {

        "bbox":

        {

          "maxx": -76.25185156,

          "maxy": 37.90686951,

          "maxz": -5.77,

          "minx": -76.25806657,

          "miny": 37.9021939,

          "minz": -35.72

        },

        "boundary": {

   "coordinates" : [

      [

         [ -76.258066569999997, 37.903041880000004 ],

         [ -76.257028300000002, 37.90686951 ],

         [ -76.251851560000006, 37.90602148 ],

         [ -76.252890100000002, 37.9021939 ],

         [ -76.258066569999997, 37.903041880000004 ]

      ]

   ],

   "type" : "Polygon"

}

 

      },

      "native":

      {

        "bbox":

        {

          "maxx": 1707557.2,

          "maxy": 1830350.12,

          "maxz": -5.77,

          "minx": 1707096.44,

          "miny": 1829911.69,

          "minz": -35.72

        },

        "boundary": {

 

 

Am I missing a switch in the translate command?

 

 

Doug

 

 

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