pycontrails.datalib.leo_utils.landsat_metadata

Download and parse Landsat metadata from USGS.

This modules requires GeoPandas.

Functions

get_time_delay_detector(ds, ephemeris, ...)

Return the detector time delay at the given (x, y) coordinates.

open_landsat_metadata([cachestore, update_cache])

Download and parse the Landsat metadata CSV file from USGS.

parse_ephemeris_landsat(ang_content)

Find the EPHEMERIS group in a ANG text file and extract the data arrays.
pycontrails.datalib.leo_utils.landsat_metadata.get_time_delay_detector(ds, ephemeris, utm_crs, x, y)

Return the detector time delay at the given (x, y) coordinates.

Parameters:

  • ds (xarray.Dataset) – The Landsat dataset containing the VAA variable.

  • ephemeris (pandas.DataFrame) – The ephemeris DataFrame containing the EPHEMERIS_TIME and ECEF coordinates.

  • utm_crs (pyproj.CRS) – The UTM coordinate reference system for the Landsat scene.

  • x (npt.NDArray[np.floating]) – The x-coordinates of the pixels in the dataset’s coordinate system.

  • y (npt.NDArray[np.floating]) – The y-coordinates of the pixels in the dataset’s coordinate system.

Returns:

npt.NDArray[np.timedelta64] – The time delay for each (x, y) coordinate as a timedelta64 array.

pycontrails.datalib.leo_utils.landsat_metadata.open_landsat_metadata(cachestore=None, update_cache=False)

Download and parse the Landsat metadata CSV file from USGS.

By default, the metadata is cached in a disk cache store.

Parameters:

  • cachestore (cache.CacheStore | None, optional) – Cache store for Landsat metadata. Defaults to cache.DiskCacheStore.

  • update_cache (bool, optional) – Force update to cached Landsat metadata. The remote file is updated daily, so this is useful to ensure you have the latest metadata.

Returns:

gpd.GeoDataFrame – Processed Landsat metadata. The geometry column contains polygons representing the footprints of the Landsat scenes.

pycontrails.datalib.leo_utils.landsat_metadata.parse_ephemeris_landsat(ang_content)

Find the EPHEMERIS group in a ANG text file and extract the data arrays.

Parameters:

ang_content (str) – The content of the ANG file as a string.

Returns:

pandas.DataFrame – A pandas.DataFrame containing the ephemeris track with columns: - EPHEMERIS_TIME: Timestamps of the ephemeris data. - EPHEMERIS_ECEF_X: ECEF X coordinates. - EPHEMERIS_ECEF_Y: ECEF Y coordinates. - EPHEMERIS_ECEF_Z: ECEF Z coordinates.