AMATERASS Data Products

AMATERASS
Product Download

Download geostationary-satellite solar radiation and photovoltaic-related products generated by AMATERASS. Select the data you need, then edit the date and file type in the sample script to download it.

View download examples Product Guide
Workflow from geostationary-satellite observations through AMATERASS analysis to data distribution
01

Select a data collection

Choose a data collection according to the satellite, observation domain, grid, and temporal interval you need.

HIMAWARI COLLECTION

HIMAWARI

Analysis products from Himawari-8 and Himawari-9 covering Japan and the broader Asia–Oceania region.

fld.4kmmsm.1kmjp01–jp04.1km
Use sample download View specifications
METEOSAT-IODC COLLECTION

METEOSAT-IODC

Solar radiation and photovoltaic-related products from METEOSAT-IODC covering the Indian Ocean region.

fld.3km4000×400015 min
Sample coming soon View specifications

Data format, filename conventions, and reading methods

The Product Guide describes available variables, observation domains, grid structures, filename conventions, binary formats, and sample reading programs.

Open Product Guide
02

Download using sample scripts

Start by downloading a single file, then edit the date and file type to retrieve a full day in batch.

UTC
AMATERASS observation times are given in UTC (Coordinated Universal Time).

For example, 2023-07-13 02:00 UTC corresponds to 2023-07-13 11:00 in Japan Standard Time (JST). Use UTC when specifying dates and times.

1

Download one file with curl

A minimal example for checking the URL and filename structure. On Windows, use curl.exe if necessary.

curl / 2023-07-13 02:00 UTC
curl -O ftp://amaterass.cr.chiba-u.ac.jp/quasi-realtime/himawari829/archived/FD/202307/20230713/202307130200.dwn.sw.flx.sfc.fld.4km.bin.bz2
REQUIRED
Reading the data requires three kinds of file.

A physical-quantity file (e.g. solar radiation) stores only the values for each observation time; location and time are in separate files. At minimum, download all three:

  • Physical-quantity file (per time) — e.g. ….dwn.sw.flx.sfc.fld.4km.bin.bz2
  • Pixel observation-time file (per time, same directory) — ….grd.time.mjd.hms.fld.4km.bin.bz2
  • Latitude / longitude grid files (shared, date-independent; download once) — tools/standard_3000x3000.lat.fld.4km.bin.bz2 and ….lng.…

The script below fetches all three (the lat/lng grid only once).

2

Download one day with Shell

For Linux / macOS. Edit YYYY, MM, DD, and FILETYPE. The script automatically selects wget or wget1.

amaterass_download_day.sh — main
Download script
YYYY=2023
MM=07
DD=13
FILETYPE="dwn.sw.flx.sfc.fld.4km.bin.bz2"
# Time is UTC.

WGET=$(select_wget) || exit 1
BASE="ftp://amaterass.cr.chiba-u.ac.jp/quasi-realtime/himawari829/archived/FD"
TOOLS="ftp://amaterass.cr.chiba-u.ac.jp/quasi-realtime/himawari829/tools"
# Pixel observation-time file (same directory / time stamp as the radiation file)
TIMETYPE="grd.time.mjd.hms.fld.4km.bin.bz2"

# Lat/lng grids do not depend on date or time: download once.
"$WGET" -c "${TOOLS}/standard_3000x3000.lat.fld.4km.bin.bz2"
"$WGET" -c "${TOOLS}/standard_3000x3000.lng.fld.4km.bin.bz2"

YYYYMM="${YYYY}${MM}"
YYYYMMDD="${YYYY}${MM}${DD}"

for HH in 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23
do
    for MN in 00 10 20 30 40 50
    do
        TIME="${YYYYMMDD}${HH}${MN}"
        DIR="${BASE}/${YYYYMM}/${YYYYMMDD}"

        # 1) solar radiation
        "$WGET" -c "${DIR}/${TIME}.${FILETYPE}"
        # 2) observation time (paired with the radiation file)
        "$WGET" -c "${DIR}/${TIME}.${TIMETYPE}"
    done
done

This example downloads one day of fld.4km downward shortwave flux and the matching observation-time files at 10-minute intervals, plus the lat/lng grid (once). If interrupted, the download can be resumed with -c.

Automatic wget / wget1 selection (normally no changes needed) 
select_wget()
{
    if command -v wget1 >/dev/null 2>&1; then
        echo wget1
    elif command -v wget >/dev/null 2>&1 && \
         ! wget --version 2>&1 | grep -q "Wget2"; then
        echo wget
    else
        echo "Error: GNU Wget 1.x (wget or wget1) is required." >&2
        exit 1
    fi
}
3

Download one day with Python

For Windows / Linux / macOS. Uses only the Python 3 standard library; no additional packages are required.

amaterass_download_day.py
Download script
from pathlib import Path
from urllib.request import urlretrieve

YYYY = "2023"
MM = "07"
DD = "13"
FILETYPE = "dwn.sw.flx.sfc.fld.4km.bin.bz2"
# Time is UTC.

BASE = "ftp://amaterass.cr.chiba-u.ac.jp/quasi-realtime/himawari829/archived/FD"
TOOLS = "ftp://amaterass.cr.chiba-u.ac.jp/quasi-realtime/himawari829/tools"
# Pixel observation-time file (same directory / time stamp as the radiation file)
TIMETYPE = "grd.time.mjd.hms.fld.4km.bin.bz2"

# Lat/lng grids do not depend on date or time: download once.
for grid in ("lat", "lng"):
    name = f"standard_3000x3000.{grid}.fld.4km.bin.bz2"
    urlretrieve(f"{TOOLS}/{name}", Path(name))

yyyymm = f"{YYYY}{MM}"
yyyymmdd = f"{YYYY}{MM}{DD}"

for hh in range(24):
    for mm in range(0, 60, 10):
        time = f"{yyyymmdd}{hh:02d}{mm:02d}"
        d = f"{BASE}/{yyyymm}/{yyyymmdd}"
        for ftype in (FILETYPE, TIMETYPE):   # radiation + observation time
            filename = f"{time}.{ftype}"
            print(f"Downloading {filename}")
            urlretrieve(f"{d}/{filename}", Path(filename))
Edit date and file typeEdit YYYY / MM / DD / FILETYPE.
Use UTCUse observation time in UTC, not local time.
Check specificationsSee the Product Guide for domains, variable codes, and file formats.
03

Data use

Before using the data, review the specifications and conditions of use for the relevant collection.

Check the data

Check the target satellite, domain, temporal interval, variable code, and file format in the Product Guide.

Conditions of use

AMATERASS data are available free of charge for educational and research use. For corporate or commercial use, please contact us in advance.

Citation and acknowledgment

When using AMATERASS data in papers, reports, or other publications, please cite the following papers.

  • Takenaka, H. et al. (2011), “Estimation of solar radiation using a neural network based on radiative transfer,” Journal of Geophysical Research: Atmospheres, 116, D08215. doi:10.1029/2009JD013337 ↗
  • Takenaka, H. et al. (2020), “Geolocation Correction for Geostationary Satellite Observations by a Phase-Only Correlation Method Using a Visible Channel,” Remote Sensing, 12(15), 2472. doi:10.3390/rs12152472 ↗
Example acknowledgmentThis study used data generated by the AMATERASS quasi-real-time solar radiation analysis system for geostationary satellite observations (developed and operated by Hideaki Takenaka).
Disclaimer

AMATERASS endeavors to maintain and improve data quality, but makes no warranty as to the accuracy, completeness, usefulness, or fitness for a particular purpose of the data provided. Use of the data is at the user's own discretion and responsibility. To the extent permitted by applicable law, the developer/operator of AMATERASS and parties involved in data distribution shall not be liable for any loss or damage arising from the use of, or inability to use, the data. Data content, distribution methods, and scope of availability may be changed or discontinued without prior notice.

04

Generation and distribution of AMATERASS products

This section identifies the origin of AMATERASS data and the distribution channels used to provide them.