1.5.1.1.7.1.18. polar2grid.readers.modis_l1b module

The MODIS Reader operates on HDF4 Level 1B files from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the Aqua and Terra satellites. The reader is designed to work with files created by the IMAPP direct broadcast processing system (file naming conventions such as a1.17006.1855.1000m.hdf), but can support other types of L1B files, including the NASA archived files (file naming conventions such as MOD021KM.A2017004.1732.005.2017023210017.hdf). The reader can be specified to the polar2grid.sh script by using the reader name modis or modis_l1b.

This reader’s default remapping algorithm is ewa for Elliptical Weighted Averaging resampling. The --weight-delta-max parameter set to 10 and the --weight-distance-max parameter set to 1.

It provides the following products:

Product Name

Description

vis01

Visible 1 Band

vis02

Visible 2 Band

vis03

Visible 3 Band

vis04

Visible 4 Band

vis05

Visible 5 Band

vis06

Visible 6 Band

vis07

Visible 7 Band

vis26

Visible 26 Band

bt20

Brightness Temperature Band 20

bt21

Brightness Temperature Band 21

bt22

Brightness Temperature Band 22

bt23

Brightness Temperature Band 23

bt24

Brightness Temperature Band 24

bt25

Brightness Temperature Band 25

bt27

Brightness Temperature Band 27

bt28

Brightness Temperature Band 28

bt29

Brightness Temperature Band 29

bt30

Brightness Temperature Band 30

bt31

Brightness Temperature Band 31

bt32

Brightness Temperature Band 32

bt33

Brightness Temperature Band 33

bt34

Brightness Temperature Band 34

bt35

Brightness Temperature Band 35

bt36

Brightness Temperature Band 36

ir20

Radiance Band 20

ir21

Radiance Band 21

ir22

Radiance Band 22

ir23

Radiance Band 23

ir24

Radiance Band 24

ir25

Radiance Band 25

ir27

Radiance Band 27

ir28

Radiance Band 28

ir29

Radiance Band 29

ir30

Radiance Band 30

ir31

Radiance Band 31

ir32

Radiance Band 32

ir33

Radiance Band 33

ir34

Radiance Band 34

ir35

Radiance Band 35

ir36

Radiance Band 36

fog

Temperature Difference between BT31 and BT20

true_color

Ratio sharpened rayleigh corrected true color

false_color

Ratio sharpened rayleigh corrected false color

For reflectance/visible products a check is done to make sure that at least 10% of the swath is day time. Data is considered day time where solar zenith angle is less than 90 degrees.

class polar2grid.readers.modis_l1b.ReaderProxy(scn: Scene, user_products: list[str])[source]

Bases: ReaderProxyBase

Provide Polar2Grid-specific information about this reader’s products.

property _aliases: dict[str, DataQuery]
get_all_products() list[str][source]

Get all polar2grid products that could be loaded.

get_default_products() list[str][source]

Get products to load if users hasn’t specified any others.

is_polar2grid_reader: bool = True
polar2grid.readers.modis_l1b.add_reader_argument_groups(parser: ArgumentParser, group: _ArgumentGroup | None = None) tuple[_ArgumentGroup | None, _ArgumentGroup | None][source]

Add reader-specific command line arguments to an existing argument parser.

If group is provided then arguments are added to this group. If not, a new group is added to the parser and arguments added to this new group.