dgm1 package¶

Submodules¶

dgm1.dgm1_nrw module¶

class dgm1.dgm1_nrw.DGM1NRW(dgm1_dir, shp_region=None)¶

Bases: object

The class DGM1NRW downloads and processes dem rasters found in https://www.opengeodata.nrw.de/produkte/geobasis/hm/dgm1_xyz/dgm1_xyz/.

Parameters

dgm1_dir (str) – directory to save downloaded 1 meter rasters as well as its shapefile and resampled rasters.
shp_region (str) – shapefile with the region of interest. If defined, all processes refer to this shapefile.

nodata = -9999.0¶: nodata for the created rasters

url_dgm1_xyz = 'https://www.opengeodata.nrw.de/produkte/geobasis/hm/dgm1_xyz/dgm1_xyz/'¶: URL of dem rasters with one meter resolution and 2000x2000 \(m^2\) size.

compress_options = ['COMPRESS=LZW', 'PREDICTOR=2']¶: Compress options used in gdal driver.Create().

creation_options = ['BIGTIFF=YES', 'COMPRESS=LZW', 'ZSTD_LEVEL=1', 'TILED=YES', 'PREDICTOR=2']¶

shp_region = None¶: Shapefile with the region of interest. If defined, all processes refer to this shapefile. Otherwise all rasters are downloaded and processed

dgm1_dir = None¶: Directory to save the original 1 meter products as well as its shapefile and resampled rasters.

shp_filename_tiles = None¶: Shapefile dgm1_2_nw.shp contaning all tiles found on the server as 2x2 \(km^2\) squares. It is saved in dgm1_dir/gis.

tif_dir(pixel_size)¶

Return the directory name of rasters with the given pixel_size. pixel_size = 1 corresponds to the downloaded rasters with 1 meter resolution.

Parameters: pixel_size (int) – pixel size in meters. It must be a divisor of 2000 (2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000).
Returns: (str) full path of the directory.

static vrt_filename(pixel_size)¶

Return the basename of the vrt-file for the given pixel size.

Parameters: pixel_size (int) – pixel size in meters. It must be a divisor of 2000 (2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000).
Returns: (str) basename of the vrt-file

tif_filenames(pixel_size)¶

Return the names of the downloaded files with the given pixel files in tif-format.

Parameters: pixel_size (int) – pixel size in meters. It must be a divisor of 2000 (2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000).
Returns: (list) full path file names.

static srs()¶

Return the compound coordinate reference system using EPSG 25832 for the horizontal component and EPSG 7837 for the vertical component. The compound srs is labeled as ETRS89 / UTM zone 32N + DHHN2016 height.

Returns: (osr.SpatialReference) spatial reference system.

region_envelope()¶

Return [x_min, y_min, x_max, y_max] for shp_region

Returns: (list) envelope of shp_region

tif_filenames_intersecting(envelope=False)¶

Return a list of file names *.xyz.gz transformed into *.tif found on the server, which intersect the region shp_region. Return an empty list if the region is not defined or it is outside the domain shp_filename_tiles.

Parameters: envelope – if True use envelopes of regions, otherwise use regions to get intersections. Default False.
Returns: (list) list of files with the suffix tif.

Example:

>>> dgm1 = DGM1NRW('~/dgm1', '~/study_area/region.shp')
>>> dgm1.tif_filenames_intersecting()
['dgm1_32350_5672_2_nw.tif', 'dgm1_32350_5674_2_nw.tif', ...

gz_filenames_intersecting(envelope=False)¶

Return a list of gzipped file names (dgm1_XXXXX_YYYY_2_nw.xyz.gz) found on the server, which intersect the region shp_region. Return an empty list if the region is not defined or it is outside the domain shp_filename_tiles.

Parameters: envelope – if True use envelopes of regions, otherwise use regions to get intersections. Default False.
Returns: (list) list of files with the suffix xyz.gz.

Example:

>>> dgm1 = DGM1NRW('~/dgm1', '~/study_area/region.shp')
>>> dgm1.gz_filenames_intersecting()
['dgm1_32350_5672_2_nw.xyz.gz', 'dgm1_32350_5674_2_nw.xyz.gz', ...

create_shapefile()¶: Create a shapefile with squares of 2x2 km² using raster file names from url_dgm1_xyz. The shapefile shp_filename_tiles is saved in dgm1_dir. The shapefile attribute Filename indicates the gz-file name found on the server. The spatial coordinate system is defined in create_spatial_reference().

download(n_cores=1)¶

Download rasters from url_dgm1_xyz intersecting shp_region. Download all rasters if region is not defined.

Parameters: n_cores – number of cores for parallel downloading and transformation into tif-files. n_core is limited to \(n\_cores \leq n - 1\), where n ist the total number of cores found on the computer. n_cores can be intentionally be high in order to use \(n - 1\) cores.

resample(pixel_size, force=False)¶

Resample dowloaded TIF files with 1 meter resolution into TIF files with a resolution of pixel_size.

Parameters

pixel_size (int) – pixel size in meters. It must be a divisor of 2000 (2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000)
force (bool) – if True, resample also existing files, otherwise skip them. Default force=False

create_vrt(vrt_filename, pixel_size=1, n_cores=1)¶

Create a raster named vrt_filename in vrt-format. A folder without the suffix .vrt will be created together with the and populated with rasters of the given pixel_size intersecting with the region.

Example:

>>> dgm1 = DGM1NRW('~/dgm1', '~/study_area/region.shp')
>>> dgm1.create_vrt('~/study_area/dgm1/dgm1_region_02m.vrt', pixel_size=2)

Parameters

vrt_filename (str) – full path vrt file name (.vrt)
pixel_size – pixel size in meters. It must be a divisor of 2000 (1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000)
n_cores (int) – number of cores for parallel downloading and transformation into TIF files. n_core is limited to \(n\_cores \leq n - 1\), where n ist the total number of cores found on the computer. n_cores can be intentionally be high in order to use \(n - 1\) cores.

mosaic(tif_filename, pixel_size, extent='region', n_cores=1, **kwargs)¶

Mosaic TIF files intersecting with the shp_region.

Parameters

tif_filename (str) – output file name (.tif)
pixel_size (int) – pixel size in meters. It must be a divisor of 2000 (1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000)
extent (str) – clip to clip shp_region; region for a raster covering the envelope of shp_region; rasters for a raster extended to full tiles. Default region. extent=None corresponds to extent=`rasters`
n_cores (int) – number of cores for parallel downloading and transformation into TIF files. n_core is limited to \(n\_cores \leq n - 1\), where n ist the total number of cores found on the computer. n_cores can be intentionally be high in order to use \(n - 1\) cores.

Keyword Arguments

See https://gdal.org/python/osgeo.gdal-module.html#WarpOptions

class dgm1.dgm1_nrw.DGM1HTMLParser¶

Bases: html.parser.HTMLParser, abc.ABC

handle_starttag(tag, attrs)¶

static get_filenames()¶

dgm1 package¶

Submodules¶

dgm1.dgm1_nrw module¶

Module contents¶