Geo¶

Classes:

`AOI`([geometry, resolution, crs, …])	A GeoContext that clips imagery to a geometry, and/or to square bounds, with any output resolution and CRS.
`DLTile`(dltile_dict[, all_touched])	A GeoContext that clips and projects imagery to a single DLTile.
`GeoContext`([all_touched])	Specifies spatial parameters to use when loading a raster from the Descartes Labs catalog.
`XYZTile`(x, y, z[, all_touched])	A GeoContext for XYZ tiles, such as those used in web maps.

class AOI(geometry=None, resolution=None, crs=None, align_pixels=True, bounds=None, bounds_crs='EPSG:4326', shape=None, all_touched=False)[source]¶

A GeoContext that clips imagery to a geometry, and/or to square bounds, with any output resolution and CRS.

Examples

cutline_aoi = dl.scenes.AOI(my_geometry, resolution=40)
aoi_with_cutline_disabled = cutline_aoi.assign(geometry=None)
no_cutline_aoi = dl.scenes.AOI(geometry=None, resolution=15, bounds=(-40, 35, -39, 36))
aoi_without_auto_bounds = dl.scenes.AOI(geometry=my_geometry, resolution=15, bounds=(-40, 35, -39, 36))
aoi_with_specific_pixel_dimensions = dl.scenes.AOI(geometry=my_geometry, shape=(200, 400))

Parameters:

geometry (GeoJSON-like dict, object with __geo_interface__; optional) – Clip imagery to this geometry. Coordinates must be WGS84 (lat-lon). If None, imagery will just be clipped to bounds.
resolution (float, optional) – Distance, in units of the CRS, that the edge of each pixel represents on the ground. Can only specify one of resolution and shape.
crs (str, optional) – Coordinate Reference System into which imagery will be projected, expressed as an EPSG code (like EPSG:4326), a PROJ.4 definition, or an OGC CRS Well-Known Text string
align_pixels (bool, optional, default True) –
If True, this ensures that, in different images rasterized with this same AOI GeoContext, pixels (i, j) correspond to the same area in space. This is accomplished by snapping the coordinates of the origin (top-left corner of top-left pixel) to a non-fractional interval of resolution.

If align_pixels is False, when using imagery with different native resolutions and/or projections, pixels at the same indicies can be misaligned by a fraction of resolution (i.e. correspond to slighly different coordinates in space).

However, this requires warping of the original image, which can be undesireable when you want to work with the original data in its native resolution and projection.
bounds (4-tuple, optional) – Clip imagery to these (min_x, min_y, max_x, max_y) bounds, expressed in bounds_crs (which defaults to WGS84 lat-lon). bounds are automatically computed from geometry if not specified. Otherwise, bounds are required.
bounds_crs (str, optional, default "EPSG:4326") – The Coordinate Reference System of the bounds, given as an EPSG code (like EPSG:4326), a PROJ.4 definition, or an OGC CRS Well-Known Text string.
shape (2-tuple, optional) – (rows, columns), in pixels, the output raster should fit within; the longer side of the raster will be min(shape). Can only specify one of resolution and shape.
all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).

assign(geometry='unchanged', resolution='unchanged', crs='unchanged', align_pixels='unchanged', bounds='unchanged', bounds_crs='unchanged', shape='unchanged', all_touched='unchanged')[source]¶

Return a copy of the AOI with the given values assigned.

Note

If you are assigning a new geometry and want bounds to updated as well, use bounds="update". This will also change bounds_crs to EPSG:4326, since the geometry’s coordinates are in WGS84 decimal degrees, so the new bounds determined from those coordinates must be in that CRS as well.

If you assign bounds without changing bounds, the new AOI GeoContext will produce rasters with the same shape and covering the same spatial area as the old one, just with pixels masked out that fall outside your new geometry.

Returns:	new
Return type:	AOI

property align_pixels¶

If True, this ensures that, in different images rasterized with this same AOI GeoContext, pixels (i, j) correspond to the same area in space. This is accomplished by snapping the coordinates of the origin (top-left corner of top-left pixel) to a non-fractional interval of resolution.

If align_pixels is False, when using imagery with different native resolutions and/or projections, pixels at the same indicies can be misaligned by a fraction of resolution (i.e. correspond to slighly different coordinates in space).

However, this requires warping of the original image, which can be undesireable when you want to work with the original data in its native resolution and projection.

Type:	bool

property bounds¶

Clip imagery to these (min_x, min_y, max_x, max_y) bounds, expressed in the coordinate reference system in bounds_crs.

Type:	tuple

property bounds_crs¶

The coordinate reference system of the bounds, given as an EPSG code (like EPSG:4326), a PROJ.4 definition, or an OGC CRS Well-Known Text string.

Type:	str

property crs¶

Coordinate reference system into which imagery will be projected, expressed as an EPSG code (like EPSG:4326), a PROJ.4 definition, or an OGC CRS Well-Known Text string.

Type:	str

property geometry¶

Clip imagery to this geometry Coordinates must be WGS84 (lat-lon). If None, imagery will just be clipped to bounds.

Type:	shapely geometry

property raster_params¶

The properties of this AOI, as keyword arguments to use for ndarray or raster.

Raises ValueError if bounds, crs, bounds_crs, resolution, or align_pixels is None.

Type:	dict

property resolution¶

Distance, in units of the CRS, that the edge of each pixel represents on the ground.

Type:	float

property shape¶

(rows, columns), in pixels, the output raster should fit within; the longer side of the raster will be min(shape).

Type:	tuple

class DLTile(dltile_dict, all_touched=False)[source]¶

A GeoContext that clips and projects imagery to a single DLTile.

DLTiles allow you to define a grid of arbitrary spacing, resolution, and overlap that can cover the globe.

DLTiles are always in a UTM projection.

Example

>>> import descarteslabs as dl
>>> from descarteslabs.geo import DLTile
>>> tile = DLTile.from_latlon(
...    lat=35.691,
...    lon=-105.944,
...    tilesize=512,
...    resolution=10,
...    pad=0
... )
>>> scenes, ctx = dl.scenes.search(tile, "landsat:LC08:PRE:TOAR")  
>>> Scenes  
    SceneCollection of 93 scenes
      * Dates: Apr 19, 2013 to Apr 14, 2017
      * Products: landsat:LC08:PRE:TOAR: 93
>>> ctx     
DLTile(key='512:0:10.0:13:-17:771',
   resolution=10.0,
   tilesize=512,
   pad=0,
   crs='EPSG:32613',
   bounds=(412960.0, 3947520.0, 418080.0, 3952640.0),
   bounds_crs='EPSG:32613',
   geometry=<shapely.geom...x7f121488c890>,
   zone=13,
   ti=-17,
   tj=771,
   geotrans=[
  412960.0,...  0,
  -10.0
], ...

Constructs a DLTile from a parameter dictionary. It is preferred to use the DLTile.from_latlon, :meth:`DLTile.from_shape(), or DLTile.from_key() class methods to construct a DLTile GeoContext.

Parameters:

dltile_dict (Dict[Str, Any]) – Dictionary for the tile.
all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).

assign(pad='unchanged', all_touched='unchanged')[source]¶

Return a copy of the DLTile with the pad and/or all_touched value modified.

Parameters:

pad (int, default "unchanged") – New pad value
all_touched (bool, default "unchanged") – New all_touched value

Returns:

tile (DLTile)
Example
——–
>>> from descarteslabs.geo import DLTile
>>> tile = DLTile.from_key(“2048 (16:30.0:15:3:80”))
>>> tile.pad
16
>>> tile = tile.assign(123)
>>> tile.pad
123

classmethod from_key(dltile_key, all_touched=False)[source]¶

Return a DLTile GeoContext from a DLTile key.

Parameters:	dltile_key (str) – DLTile key, e.g. ‘128:16:960.0:15:-1:37’ all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).
Returns:	tile
Return type:	DLTile

Example

>>> from descarteslabs.geo import DLTile
>>> tile = DLTile.from_key("2048:16:30.0:15:3:80")
>>> tile            
DLTile(key='2048:16:30.0:15:3:80',
       resolution=30.0,
       tilesize=2048,
       pad=16,
       crs='EPSG:32615',
       bounds=(683840.0, 4914720.0, 746240.0, 4977120.0),
       bounds_crs='EPSG:32615',
       geometry=<shapely.geom...>,
       zone=15,
       ti=3,
       tj=80,
       geotrans=[
...

classmethod from_latlon(lat, lon, resolution, tilesize, pad, all_touched=False)[source]¶

Return a DLTile GeoContext that covers a latitude/longitude.

Where the point falls within the tile will vary, depending on the point and tiling parameters.

Parameters:	lat (float) – Latitude (WGS84) lon (float) – Longitude (WGS84) resolution (float) – Distance, in meters, that the edge of each pixel represents on the ground tilesize (int) – Length of each side of the tile, in pixels pad (int) – Number of extra pixels by which each side of the tile is buffered. This determines the number of pixels by which two tiles overlap. all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).
Returns:	tile
Return type:	DLTile

Example

>>> from descarteslabs.geo import DLTile
>>> # make a tile with total size 100, centered on lat, lon
>>> # total tilesize == tilesize + 2 * pad
>>> params = {
...    "lat": 30.0131,
...    "lon": 31.2089,
...    "resolution": 10,
...    "tilesize": 2,
...    "pad": 49,
... }
>>> tile = DLTile.from_latlon(**params)
>>> tile.key
'2:49:10.0:36:-8637:166079'
>>> tile.geometry.centroid.xy  
(array('d', [31.20899205942612]), array('d', [30.013121672688087]))

classmethod from_shape(shape, resolution, tilesize, pad, keys_only=False, all_touched=False)[source]¶

Return a list of DLTiles that intersect the given geometry.

Parameters:	shape (GeoJSON-like) – A GeoJSON dict, or object with a `__geo_interface__`. Must be in `EPSG:4326` (WGS84 lat-lon) projection. resolution (float) – Distance, in meters, that the edge of each pixel represents on the ground. tilesize (int) – Length of each side of the tile, in pixels. pad (int) – Number of extra pixels by which each side of the tile is buffered. This determines the number of pixels by which two tiles overlap. keys_only (bool, default False) – Whether to return DLTile objects or only DLTile keys. Set to True when returning a large number of tiles and you do not need the full objects. all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).
Returns:	tiles
Return type:	List[DLTile] or List[Str]

Example

>>> from descarteslabs.geo import DLTile
>>> shape = {
... "type":"Feature",
... "geometry":{
...     "type":"Polygon",
...     "coordinates":[[
...            [-122.51140471760839,37.77130087547876],
...            [-122.45475646845254,37.77475476721895],
...            [-122.45303985468301,37.76657207194229],
...            [-122.51057242081689,37.763446782666094],
...            [-122.51140471760839,37.77130087547876]]]
...    },"properties": None
... }
>>> tiles = DLTile.from_shape(
...    shape=shape,
...    resolution=1,
...    tilesize=500,
...    pad=0,
... )
>>> len(tiles)
31

classmethod iter_from_shape(shape, resolution, tilesize, pad, keys_only=False, all_touched=False)[source]¶

Return a iterator for DLTiles that intersect the given geometry.

Parameters:	shape (GeoJSON-like) – A GeoJSON dict, or object with a `__geo_interface__`. Must be in `EPSG:4326` (WGS84 lat-lon) projection. resolution (float) – Distance, in meters, that the edge of each pixel represents on the ground. tilesize (int) – Length of each side of the tile, in pixels. pad (int) – Number of extra pixels by which each side of the tile is buffered. This determines the number of pixels by which two tiles overlap. keys_only (bool, default False) – Whether to return DLTile objects or only DLTile keys. Set to True when returning a large number of tiles and you do not need the full objects. all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).
Returns:
Return type:	Iterator of DLTiles or str

Example

>>> from descarteslabs.geo import DLTile
>>> shape = {
... "type":"Feature",
... "geometry":{
...     "type":"Polygon",
...     "coordinates":[[
...            [-122.51140471760839,37.77130087547876],
...            [-122.45475646845254,37.77475476721895],
...            [-122.45303985468301,37.76657207194229],
...            [-122.51057242081689,37.763446782666094],
...            [-122.51140471760839,37.77130087547876]]]
...    },"properties": None
... }
>>> gen = DLTile.from_shape(
...    shape=shape,
...    resolution=1,
...    tilesize=500,
...    pad=0,
...    keys_only=True
... )
>>> tiles = [tile for tile in gen]  
>>> tiles[0]                        
'500:0:1.0:10:94:8359'

latlon_to_rowcol(lat, lon)[source]¶

Convert lat, lon coordinates to pixel coordinates

Parameters:	lat (float or List[float]) – Latitude coordinate or coordinates lon (float or List[float]) – Longitude coordinate or coordinates
Returns:	coords – Tuple with the first element the row values and the second element column values
Return type:	List[Tuple[int] Tuple[int]]

Example

>>> from descarteslabs.geo import DLTile
>>> tile = DLTile.from_key("2048:0:30.0:15:3:80")
>>> tile.latlon_to_rowcol(lat=44.8, lon=-90.2)
[(403,), (1237,)]

rowcol_to_latlon(row, col)[source]¶

Convert pixel coordinates to lat, lon coordinates

Parameters:	row (int or List[int]) – Pixel row coordinate or coordinates col (int or List[int]) – Pixel column coordinate or coordinates
Returns:	coords – List with the first element the latitude values and the second element longitude values
Return type:	List[Tuple[float], Tuple[float]]

Example

>>> from descarteslabs.geo import DLTile
>>> tile = DLTile.from_key("2048:0:30.0:15:3:80")
>>> tile.rowcol_to_latlon(row=56, col=1111)
[(44.894653081367544,), (-90.24334206726267,)]

subtile(subdivide, resolution=None, pad=None, keys_only=False)[source]¶

Return an iterator for new DLTiles that subdivide this tile.

The DLtile will be sub-divided into subdivide^2 total sub-tiles each with a side length of tile_size / subdivide. The resulting sub-tile size must be an integer. Each sub-tile will by default inherit the same resolution and pad as the orginal tile.

Parameters:

subdivide (int) – The value to subdivide the tile. The total number of sub-tiles will be the square of this value. This value must evenly divide the original tilesize.
resolution (None, float) – A new resolution for the sub-tiles. None defaults to the original DLTile resolution. The new resolution must evenly divide the the original tilesize divided by the subdivide ratio.
pad (None, int) – A new pad value for the sub-tiles. None defaults to the original DLTile pad value.
keys_only (bool, default False) – Whether to return DLTile objects or only DLTile keys. Set to True when returning a large number of tiles and you do not need the full objects.

Returns:

Iterator over DLTiles or str
Example
——-
>>> from descarteslabs.geo import DLTile
>>> tile = DLTile.from_key(“2048 (0:30.0:15:3:80”))
>>> tiles = [tile for tile in tile.subtile(8)]
>>> len(tiles)
64
>>> tiles[0].tilesize
256

property bounds¶

The (min_x, min_y, max_x, max_y) of the area covered by this DLTile, in the UTM coordinate reference system given in bounds_crs.

Type:	tuple

property bounds_crs¶

The coordinate reference system of the bounds, given as an EPSG code (like EPSG:32615). A DLTile’s CRS is always UTM.

Type:	str

property crs¶

Coordinate reference system into which imagery will be projected. For DLTiles, this is always a UTM projection, given as an EPSG code.

Type:	str

property geometry¶

The polygon covered by this DLTile in WGS84 (lat-lon) coordinates

Type:	shapely.geometry.Polygon

property geotrans¶

The 6-tuple GDAL geotrans for this DLTile in the shape (a, b, c, d, e, f) where

a is the top left pixel’s x-coordinate
b is the west-east pixel resolution
c is the row rotation, always 0 for DLTiles
d is the top left pixel’s y-coordinate
e is the column rotation, always 0 for DLTiles
f is the north-south pixel resolution, always a negative value

Type:	tuple

property key¶

The DLTile’s key, which encodes the tiling parameters, and which number in the grid this tile is.

Type:	str

property pad¶

Number of extra pixels by which each side of the tile is buffered. This determines the number of pixels by which two tiles overlap.

Type:	int

property proj4¶

PROJ.4 definition for this DLTile’s coordinate reference system

Type:	str

property raster_params¶

The properties of this DLTile, as keyword arguments to use for Raster.ndarray or Raster.raster.

Type:	dict

property resolution¶

Distance, in meters, that the edge of each pixel represents on the ground

Type:	float

property ti¶

The y-index of this tile in its grid

Type:	int

property tile_extent¶

total extent of geocontext length in pixels, including pad. Size is tile_size + 2 * pad.

Type:	int

property tilesize¶

Length of each side of the tile, in pixels. Note that the total number of pixels along each side of an image is tile_size + 2 * padding

Type:	int

property tj¶

The x-index of this tile in its grid

Type:	int

property wkt¶

OGC Well-Known Text definition for this DLTile’s coordinate reference system

Type:	str

property zone¶

The UTM zone of this tile

Type:	int

class GeoContext(all_touched=False)[source]¶

Specifies spatial parameters to use when loading a raster from the Descartes Labs catalog.

Two Scenes loaded with the same GeoContext will result in images with the same shape (in pixels), covering the same spatial extent, regardless of the dimensions or projection of the original data.

Specifically, a fully-defined GeoContext specifies:

geometry to use as a cutline (WGS84), and/or bounds
resolution (m)
EPSG code of the output coordinate reference system
whether to align pixels to the output CRS (see docstring for AOI.align_pixels for more information)

GeoContexts are immutable.

Parameters:	all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).

property all_touched¶

If True, this ensures that any source pixel which intersects the GeoContext contributes to the raster result.

Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).

Type:	bool

property raster_params¶

The properties of this GeoContext, as keyword arguments to use for Raster.ndarray or Raster.raster.

Type:	dict

class XYZTile(x, y, z, all_touched=False)[source]¶

A GeoContext for XYZ tiles, such as those used in web maps.

The tiles are always 256x256 pixels, in the spherical Mercator or “Web Mercator” coordinate reference system (EPSG:3857).

Parameters:

x (int) – X-index of the tile (increases going east)
y (int) – Y-index of the tile (increases going south)
z (int) – Zoom level of the tile
all_touched (bool, default False) – If True, this ensures that any source pixel which intersects the AOI GeoContext contributes to the raster result. Normally this mode is not enabled, and its use is strongly discouraged. However, it can be useful when the AOI is smaller than a source pixel, which under many situations will return no result at all (i.e. entirely masked).

children()[source]¶: List of child XYZTiles contained within this one

parent()[source]¶: The parent XYZTile enclosing this one

property bounds¶

The (min_x, min_y, max_x, max_y) of the area covered by this XYZTile, in spherical Mercator coordinates (EPSG:3857).

Type:	tuple

property bounds_crs¶

The coordinate reference system of the bounds. Always EPSG:3857 (spherical Mercator, aka “Web Mercator”)

Type:	str

property crs¶

Coordinate reference system into which common.geo will be projected. Always EPSG:3857 (spherical Mercator, aka “Web Mercator”)

Type:	str

property geometry¶

The polygon covered by this XYZTile in WGS84 (lat-lon) coordinates

Type:	shapely.geometry.Polygon

property raster_params¶

The properties of this XYZTile, as keyword arguments to use for Raster.ndarray or Raster.raster.

Type:	dict

property resolution¶

Distance, in meters, that the edge of each pixel represents in the spherical Mercator (“Web Mercator”, EPSG:3857) projection.

Type:	float

property tilesize¶

Length of each side of the tile, in pixels. Always 256.

Type:	int

property x¶

X-index of the tile (increases going east)

Type:	int

property y¶

Y-index of the tile (increases going south)

Type:	int

property z¶

Zoom level of the tile

Type:	int