Configuration¶

Tile Specification¶

A tile specification describes the positioning, grid layout, and coordinate reference system that ingested imagery will be reprojected, diced, and aligned to match with.

A tile specification is described by four attributes:

crs (str): The coordinate reference system, given as a Proj4 string or Well-Known-Text.
ul (tuple): The upper left X and Y coordinates of the tile specification
res (tuple): The pixel resolution of data in the tile specification
size (tuple): The number of pixels (columns and rows) in each tile. The total area covered by a tile is a function of the pixel size and the number of pixels per tile.

Tilezilla includes a few “well known specifications” that include:

WELD_CONUS
- crs: “EPSG:5070”
- ul: [-2565600.0, 3314800.0]
- res: [30, 30]
- size: [5000, 5000]

Database¶

Tilezilla’s database backend is written using SQLAlchemy ORM to abstract as much as possible away from the type of database used. Currently, only SQLite has been tested but the structure should be in place to switch to something more complex (e.g., PostgreSQL).

SQLite¶

Todo

Describe SQLite configuration

Storage¶

Tiled data are stored on disk either as a collection of GeoTIFF images or NetCDF4 files.

Currently, only the GeoTIFF storage format is implemented.

GeoTIFF¶

Todo

Document the GeoTIFF storage format

Products¶

Todo

Write about existing products (ESPALandsat) and how one can write YAML file to describe arbitrary products for ingest

Example¶

The following example configuration file describes the configuration needed to ingest Landsat data processed to surface reflectance through the ESPA system into a tiling scheme that has the same parameters as the Web Enabled Landsat Data (WELD) tiled data product.

The include_filter option in the products section limits the ingest to only include surface reflectance, brightness temperature, and CFmask bands. Any reprojection necessary for this ingest will be done using nearest neighbor resampling.

# Metadata
version: 0.1.0

# Database
# See connection information at:
# http://docs.sqlalchemy.org/en/latest/core/engines.html#sqlalchemy.engine.url.URL
database:
    drivername: sqlite
    database: /home/ceholden/tiles/tilezilla.db
    # Not required, but used with postgresql, etc.
    # username:
    # password:
    # host:
    # port:
    debug: False

# Tile storage method
store:
    ## Required
    name: GeoTIFF  # could be NetCDF
    root: /home/ceholden/tiles
    tile_dirpattern: 'h{horizontal:04d}v{vertical:04d}'
    tile_imgpattern: '{product.timeseries_id}_{band.standard_name}.tif'
    ## Additional option -- specific (?) to GeoTIFF: creation options
    co:
        tiled: true
        blockxsize: 256
        blockysize: 256
        compress: deflate


# Tile specification
## For recognized systems
tilespec: WELD_CONUS
## Or manually
# tilespec:
#     # Coordinate reference system
#     crs: EPSG:5070
#     # Upper left x/y coordinate
#     ul: 15, 15
#     # Resolution (x/y) of each pixel
#     res: 30, 30
#     # Number of pixels (x/y) in each tile
#     size: 500, 500


# Products
products:
    ## Product handling options, specified by product type
    ESPALandsat:
        include_filter:
            regex: false
            # Attributes of each product band to include
            long_name:
                - '*surface reflectance*'
                - '*brightness temperature*'
                - '*cfmask_band*'
        resampling: nearest