[pdal] Z value change on reprojection in pdal 1.6
Doug Newcomb
newcomb.ttg at gmail.com
Tue Nov 14 06:58:25 PST 2017
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 at dnewcomb
+----------------------------------------------------------------------------+
| Map: noaa_pdal_vert_diff_m at 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 at dnewcomb -
|
| 2635_mean_ground_1_524 at PERMANENT
|
|
|
+----------------------------------------------------------------------------+
Doug
On Mon, Nov 13, 2017 at 8:20 PM, Michael Smith <michael.smith.erdc at gmail.com
> 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 <pdal-bounces at lists.osgeo.org> on behalf of Doug Newcomb <
> newcomb.ttg at gmail.com>
> *Date: *Monday, November 13, 2017 at 8:14 PM
> *To: *pdal <pdal at lists.osgeo.org>
> *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
> pdal at lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/pdal
>
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