cmaqsatproc.readers.viirs package

Module contents

class cmaqsatproc.readers.viirs.AERDB_L2_VIIRS_SNPP[source]

Bases: L2_VIIRS_SNPP

  • valid = Aerosol_Optical_Thickness_550_Land_Ocean_Best_Estimate not None

  • pixel corners are based on interpolated lat/lon

classmethod cmaq_process(qf, satl3f)[source]

Process CMAQ as though it were observed by VIIRS, which is simply based on the overpass time.

Parameters:

  • qf (xarray.Dataset) – CMAQ file that has composition (e.g., NH3)

  • satl3f (xarray.Dataset) – Output from to_level3, paths_to_level3, or cmr_to_level3 with as_dataset=True (the default).

Returns:

overf – An overpass file with satellite-like CMAQ.

Return type:

xr.DataArray

Thin wrapper around L2_VIIRS_SNPP.cmr_links with concept_id set to C2600303218-LAADS.

Parameters:

method (str) – ‘opendap’, ‘download’, or ‘s3’.

Returns:

links – List of links for download or OpenDAP or s3

Return type:

list

classmethod prep_dataset(ds, bbox=None, isvalid=2, path=None)[source]

Applies spatial subset based on Latitude and Longitude, also interpolates pixel centers to corners and applies valid flags:

  • AOT_QA_Flag_Land >= isvalid, or

  • AOT_QA_Flag_Ocean >= isvalid

  • and ~AOT_550_Land_Ocean_Best_Estimate.isnull()

  • where AOT = Aerosol_Optical_Thickness

Parameters:

  • ds (xarray.Dataset) – Satellite dataset

  • bbox (iterable) – swlon, swlat, nelon, nelat in decimal degrees East and North

  • isvalid (float) – Value greater than or equal to 2 are valid.

  • path (str) – Unused.

Returns:

ds

Return type:

xarray.Dataset

class cmaqsatproc.readers.viirs.AERDT_L2_VIIRS_SNPP[source]

Bases: L2_VIIRS_SNPP

  • valid = Land_Ocean_Quality_Flag > isvalid (default 2)

  • pixel corners are based on interpolated lat/lon

classmethod cmaq_process(qf, l3)[source]

Process CMAQ as though it were observed by VIIRS, which is simply based on the overpass time.

Parameters:

  • qf (xarray.Dataset) – CMAQ file that has composition (e.g., NH3)

  • l3 (xarray.Dataset) – Output from to_level3, paths_to_level3, or cmr_to_level3 with as_dataset=True (the default).

Returns:

overf – An overpass file with satellite-like CMAQ.

Return type:

xr.DataArray

Thin wrapper around L2_VIIRS_SNPP.cmr_links with concept_id set to C1688453112-LAADS.

Parameters:

method (str) – ‘opendap’, ‘download’, or ‘s3’.

Returns:

links – List of links for download or OpenDAP or s3

Return type:

list

classmethod prep_dataset(ds, bbox=None, isvalid=2, path=None)[source]

Applies spatial subset based on Latitude and Longitude, also interpolates pixel centers to corners and applies valid flags:

  • Land_Ocean_Quality_Flag >= isvalid

  • ~Optical_Depth_Land_And_Ocean.isnull()

Parameters:

  • ds (xarray.Dataset) – Satellite dataset

  • bbox (iterable) – swlon, swlat, nelon, nelat in decimal degrees East and North

  • isvalid (float) – Value greater than or equal to 2 are valid.

  • path (str) – Unused.

Returns:

ds

Return type:

xarray.Dataset

class cmaqsatproc.readers.viirs.L2_VIIRS_SNPP[source]

Bases: satellite

VIIRS SNPP * valid = Land_Ocean_Quality_Flag > isvalid (default 2) * pixel corners are based on interpolated lat/lon

Reimplemenation of satellite.cmr_links to account for html links in VIIRS OpenDAP links in the CMR.

Parameters:

method (str) – ‘opendap’, ‘download’, or ‘s3’.

Returns:

links – List of links for download or OpenDAP or s3

Return type:

list

classmethod open_dataset(path, bbox=None, isvalid=2, **kwargs)[source]

Open a local or remote path as a VIIRS satellite processor.

Parameters:

  • path (str) – Path to a L2_VIIRS_SNPP OpenDAP-style file

  • bbox (iterable) – swlon, swlat, nelon, nelat in decimal degrees East and North

  • isvalid (float) – Minimum value of flag for valid date (flag>=isvalid)

  • kwargs (mappable) – Passed to xarray.open_dataset

Returns:

sat – Satellite processing instance

Return type:

L2_VIIRS_SNPP