[GRASS-user] Importing .tif

Sat Jul 14 00:10:09 PDT 2018

Rich, I downloaded a sample LDQ file: 'LDQ-43120C4.zip'.

Some '.tif' files are inside the subdirectory 'Intensity'. GDAL says for
one of them:
```
gdalinfo int_43120C4404.tif -proj4 -nomd

Driver: GTiff/GeoTIFF
Files: int_43120C4404.tif
       int_43120C4404.tif.ovr
       int_43120C4404.tif.aux.xml
Size is 865, 1739
Coordinate System is:
PROJCS["NAD_1983_CORS96_UTM_Zone_10N",
    GEOGCS["GCS_NAD_1983_CORS96",
        DATUM["NAD_1983_CORS96",
            SPHEROID["GRS_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-123],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
PROJ.4 string is:
'+proj=utm +zone=10 +ellps=GRS80 +units=m +no_defs '
Origin = (711475.000000000000000,4798302.500000000000000)
Pixel Size = (0.500000000000000,-0.500000000000000)
Corner Coordinates:
Upper Left  (  711475.000, 4798302.500) (120d23'32.93"W, 43d18'28.22"N)
Lower Left  (  711475.000, 4797433.000) (120d23'34.13"W, 43d18' 0.06"N)
Upper Right (  711907.500, 4798302.500) (120d23'13.75"W, 43d18'27.78"N)
Lower Right (  711907.500, 4797433.000) (120d23'14.96"W, 43d17'59.62"N)
Center      (  711691.250, 4797867.750) (120d23'23.94"W, 43d18'13.92"N)
Band 1 Block=128x128 Type=Byte, ColorInterp=Gray
  Min=15.000 Max=223.000
  Minimum=15.000, Maximum=223.000, Mean=111.348, StdDev=14.186
  NoData Value=0
  Overviews: 433x870, 217x435
```

Indeed, using this file's geo-metadata to create a new GRASS location,
ends up in `r.in.gdal` complaining while performing the projection
check.

Perhaps the geo-metadata in these .tif files are not a good match for
GRASS GIS (and its mechanism to detect reference systems).

The 'Shapefiles' directory contains various ancillary vector maps. One
such map is 'OLC_1-100th_Quadrangle_Index.shp' whose corresponding .prj
file content is:

PROJCS["NAD_1983_HARN_StatePlane_Oregon_North_FIPS_3601_Feet_Intl",GEOGCS["GCS_North_American_1983_HARN",DATUM["D_North_American_1983_HARN",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",8202099.737532808],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-120.5],PARAMETER["Standard_Parallel_1",44.33333333333334],PARAMETER["Standard_Parallel_2",46.0],PARAMETER["Latitude_Of_Origin",43.66666666666666],UNIT["Foot",0.3048]]

The file 'OLC_EASTERN_OR_TIR_2012_0_75_UTM.prj', however, appears to be
a match for the .tif file (?).

PROJCS["NAD_1983_CORS96_UTM_Zone_10N",GEOGCS["GCS_NAD_1983_CORS96",DATUM["D_NAD_1983_CORS96",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-123.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]]

I used this vector map as a source, created a new Location/Mapset,
imported one '.tif' file without problems. The "FIPS 3601" is not the
correct one to use for the '.tif' files, in this example LDQ I
downloaded.

Hope the above is useful for you too.

Nikos

* Rich Shepard <rshepard at appl-ecosys.com> [2018-07-13 15:47:34 -0700]:

>  I've not found specific information on importing *.tif rasters so I winged
>it to import a LiDAR Digital Quad (LDQ) map. This is my work flow and how
>grass7.5svn responded.
>
>  0. There are 4 files for each of the LDQs: *.aux, *.tfw, *.tif, and
>*.tif.xml.
>
>  1. Looking at the file, *.tif.xml, I learned the projection is
>FIPS 3601. A web page listing FIPS codes and their EPSG equivalents showed
>the latter is 32126.
>
>  2. The command, 'grass75 -c EPSG:32126' created a new location.
>
>  3. r.in.gdal in=$HOME/projects/oregon/estacada-rock/data/topography/estacada-45122c3/2009_OLC_Hood-to-Coast/45122c3302.tif out=ldq
>ERROR: Projection of dataset does not appear to match current location.
>
>       Dataset PROJ_INFO is:
>       name: NAD83(HARN) / Oregon North
>       datum: nad83harn
>       ellps: grs80
>       proj: lcc
>       lat_1: 46
>       lat_2: 44.33333333333334
>       lat_0: 43.66666666666666
>       lon_0: -120.5
>       x_0: 2500000
>       y_0: 0
>       towgs84: 0,0,0,0,0,0,0
>       no_defs: defined
>
>       ERROR: proj
>
>  This is my first question: Since the .xml file showed the projection as
>FIPS 3601, and the equivalent EPSG code is 32126 is used to create the
>location, why does grass75 see a mis-match?
>
>  4. r.in.gdal -o in=$HOME/projects/oregon/estacada-rock/data/topography/estacada-45122c3/2009_OLC_Hood-to-Coast/45122c3302.tif out=ldq
>Over-riding projection check
>Importing 3 raster bands...
>Importing raster map <ldq.red>...
> 100%
>Importing raster map <ldq.green>...
> 100%
>Importing raster map <ldq.blue>...
> 100%
>
>  This is my second question: While I can display each map in the monitor,
>they all look the same. Displaying one after the other produces no change in
>appearance. So, have I correctly imported the LDQ and do the different color
>bands matter?
>
>  This LDQ is produced by the intensity of returns of the highest hits in
>the area of coverage. It looks like a low resolution black-and-white aerial
>photograph while generated from 1.5' (45cm) horizontal resolution LiDAR
>scans (see attached screenshot.png). Really helpful in correlating specific
>project areas to the elevation map and other features.
>
>Carpe weekend,
>
>Rich
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