4.3. AHI HimawariCast (HRIT) Reader

The AHI High Rate Information Transmission (HRIT) Reader operates on standard Japan Meteorological Agency (JMA) Himawari-8 Advanced Himawari Imager (AHI) HRIT Digital Video Broadcast (DVB) HimawariCast files. This broadcast consists of a subset of 14 bands at reduced spatial resolution. The AHI HRIT reader works off of the input filenames to determine if a file is supported by Geo2Grid. Files usually have the following naming scheme:

IMG_DK01B04_201809100300

These are the mission compliant radiance file naming conventions used by JMA. The AHI HRIT reader supports a subset of instrument spectral bands, identified in Geo2Grid as the products shown in the table below. The AHI HRIT reader can be provided to the main geo2grid.sh script using the -r option and the reader name ahi_hrit.

The list of supported products includes natural color imagery. This is created by means of a python based atmospheric Rayleigh scattering correction algorithm that is executed as part of the Geo2Grid AHI HRIT reader, along with sharpening to the highest spatial resolution.

Please note that true color image RGB creation is not supported for HimawariCast because AHI Band 1 (Blue) and Band 2 (Green) are not included.

For more information on the creation of RGBs, please see the RGB section.

Product Name

Description

B03

Channel 3 Reflectance Band

B04

Channel 4 Reflectance Band

B05

Channel 5 Reflectance Band

B06

Channel 6 Reflectance Band

B07

Channel 7 Brightness Temperature Band

B08

Channel 8 Brightness Temperature Band

B09

Channel 9 Brightness Temperature Band

B10

Channel 10 Brightness Temperature Band

B11

Channel 11 Brightness Temperature Band

B12

Channel 12 Brightness Temperature Band

B13

Channel 13 Brightness Temperature Band

B14

Channel 14 Brightness Temperature Band

B15

Channel 15 Brightness Temperature Band

B16

Channel 16 Brightness Temperature Band

natural_color

Ratio sharpened rayleigh corrected natural color

airmass

Air mass RGB

ash

Ash RGB

dust

Dust RGB

fog

Fog RGB

night_microphysics

Night Microphysics RGB

4.3.1. Command Line Usage

usage: geo2grid.sh -r ahi_hrit -w <writer> [-h]

Examples:

geo2grid.sh -r ahi_hrit -h

geo2grid.sh -r ahi_hrit -w geotiff --list-products -f /ahi8/hcast/2330

geo2grid.sh -r ahi_hrit -w geotiff -f /ahi8/hcast/IMG_DK01IR4_201811122330

geo2grid.sh -r ahi_hrit -w geotiff -p B03 B04 B05 B06 B16 natural_color --num-workers 8 -f /hrit/ahi/

geo2grid.sh -r ahi_hrit -w geotiff --ll-bbox 125 -15 160 10 -f /data/hsd/IMG_DK01*