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NAME

i.modis.download - Download single or multiple tiles of MODIS products using pyModis.

KEYWORDS

raster, import, MODIS

SYNOPSIS

i.modis.download
i.modis.download --help
i.modis.download [-dgcl] [settings=name] [product=string[,string,...]] [tiles=string] [startday=string] [endday=string] [folder=string] [--help] [--verbose] [--quiet] [--ui]

Flags:

-d
Debug mode, writing more info into the log file
-g
Return the name of file containing the list of HDF tiles downloaded in shell script style
-c
Do not perform GDAL check on downloaded images
-l
List more info about the supported MODIS products
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog

Parameters:

settings=name
Full path to settings file or '-' for standard input, empty for .netrc file
Name of input file
product=string[,string,...]
Name of MODIS product(s)
Options: lst_terra_daily_1000, lst_aqua_daily_1000, lst_terra_eight_1000, lst_aqua_eight_1000, lst_terra_daily_5600, lst_aqua_daily_5600, lst_terra_monthly_5600, lst_aqua_monthly_5600, ndvi_terra_sixteen_250, ndvi_aqua_sixteen_250, ndvi_terra_sixteen_500, ndvi_aqua_sixteen_500, ndvi_terra_sixteen_1000, ndvi_aqua_sixteen_1000, ndvi_terra_sixteen_5600, ndvi_aqua_sixteen_5600, ndvi_terra_monthly_1000, ndvi_aqua_monthly_1000, ndvi_terra_monthly_5600, ndvi_aqua_monthly_5600, snow_terra_daily_500, snow_aqua_daily_500, snow_terra_eight_500, snow_aqua_eight_500, surfreflec_terra_daily_500, surfreflec_aqua_daily_500, surfreflec_terra_eight_500, surfreflec_aqua_eight_500, water_terra_250, aerosol_terra_aqua_daily_1000
Default: lst_terra_daily_1000
tiles=string
The name(s) of tile(s) to download (comma separated). If not set, all available tiles are downloaded
e.g.: h18v04
startday=string
First date to download
Format: YYYY-MM-DD. If not set the download starts from current date and goes back 10 days. If not endday is set, the download stops 10 days after the startday
endday=string
Last date to download
Format: YYYY-MM-DD. To use only with startday
folder=string
Folder to store the downloaded data
If not set, path to settings file is used

Table of contents

DESCRIPTION

i.modis.download downloads selected MODIS products (Moderate Resolution Imaging Spectroradiometer, flown on the two NASA spacecrafts Terra and Aqua). The module can download several tiles at once and also multiple observation dates for each MODIS product.

NOTES

The i.modis modules need the pyModis library. Please install it beforehand.

To be able to download data the user needs to obtain user and password for the NASA Earthdata Login:

In order to download the desired MODIS product(s), the username and password must be provided through the settings option. There are three ways:

Warning: As per NASA policy no more than ten simultaneous connections are permitted in parallel with their server. Hence, no more than ten processes of i.modis.download should run at the same time to avoid that user's actual IP address gets blacklisted.

By default, the downloaded files are stored in the path in which the settings file was saved. The user can change this directory with the folder option. The folder option is required when user and password are passed through the standard input.

The needed time for the download depends on the number of requested tiles, days and the type of MODIS product. For example, the NDVI product ranges from 5 MB to 270 MB and the LST product ranges from 2 MB to 21 MB.

EXAMPLES

MODIS NDVI Global

Download of the global MODIS product MOD13C1 - MODIS/Terra Vegetation Indices 16-Day L3 Global 0.05Deg CMG V006 by selecting a specific month, using the credentials conveniently stored in
$HOME/.netrc
file:
# note: provided in Geographic Lat/Long Grid
i.modis.download product=ndvi_terra_sixteen_5600 startday=2020-05-01 endday=2020-05-31 folder=/path/to/modisdata/

MODIS Land Surface Temperature

Download of the daily MODIS LST product "lst_terra_daily_1000" from the Terra satellite using the default options (all available tiles from newest available date) and passing the user and password through standard input. Note that when settings is read from standard input, the option folder must be specified:
i.modis.download settings=- folder=/path/to/modisdata/

Reading the user and password options from a file (this will download by default the "lst_terra_daily_1000" product). MODIS data will be downloaded to the folder where the SETTING file is:

i.modis.download settings=$HOME/.grass8/i.modis/SETTING

Download of the LST Terra product using the default options and change of the starting and ending dates to custom values:

i.modis.download settings=$HOME/.grass8/i.modis/SETTING startday=2011-05-01 endday=2011-05-31 folder=/path/to/modisdata/

MODIS Snow

Download of a different product (here: Snow eight days 500 m), default options (for settings, see example above):
i.modis.download settings=$HOME/.grass8/i.modis/SETTING product=snow_terra_eight_500 folder=/path/to/modisdata/

MODIS NDVI Global

Download of a global MODIS product (here: MOD13C1 - MODIS/Terra Vegetation Indices 16-Day L3 Global 0.05Deg CMG V061), of a specific month (for settings, see example above):
# note: provided in Geographic Lat/Long Grid
i.modis.download settings=$HOME/.grass8/i.modis/SETTING product=ndvi_terra_sixteen_5600 startday=2011-05-01 endday=2011-05-31 folder=/path/to/modisdata/

Download of MODIS data in scripts

To use i.modis.download in a script and to concatenate it with another module, the user needs to set the -g flag to return the name of the file that contains the list of downloaded HDF files:
i.modis.download -g settings=$HOME/.grass8/i.modis/SETTING startday=2011-05-01 endday=2011-05-31 folder=/path/to/modisdata/

SEE ALSO

i.modis, i.modis.import

GRASS GIS Wiki: temporal data processing

Map of MODIS Land products' Sinusoidal grid tiling system

AUTHOR

Luca Delucchi, Google Summer of Code 2011; subsequently updated.

SOURCE CODE

Available at: i.modis.download source code (history)

Latest change: Saturday Sep 09 18:12:43 2023 in commit: d6bf9ae996af26a9072f7d29b99c309d9a28b662


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