download_modis: Download MODIS product files

In amadeus: Accessing and Analyzing Large-Scale Environmental Data

Download MODIS product files

Description

Need maintenance for the directory path change in NASA EOSDIS. This function first retrieves the all hdf download links on a certain day, then only selects the relevant tiles from the retrieved links. Download is only done at the queried horizontal-vertical tile number combinations. An exception is MOD06_L2 product, which is produced every five minutes every day.

Usage

download_modis(
  product = c("MOD09GA", "MYD09GA", "MOD09GQ", "MYD09GQ", "MOD09A1", "MYD09A1",
    "MOD09Q1", "MYD09Q1", "MOD11A1", "MYD11A1", "MOD11A2", "MYD11A2", "MOD11B1",
    "MYD11B1", "MOD13A1", "MYD13A1", "MOD13A2", "MYD13A2", "MOD13A3", "MYD13A3",
    "MOD06_L2", "MCD19A2", "VNP46A2"),
  version = "061",
  nasa_earth_data_token = NULL,
  date = c("2023-09-01", "2023-09-01"),
  extent = c(-125, 22, -64, 50),
  directory_to_save = NULL,
  acknowledgement = FALSE,
  download = FALSE,
  remove_command = FALSE,
  hash = FALSE
)

Arguments

product	character(1). One of c("MOD09GA", "MOD11A1", "MOD06_L2", "MCD19A2", "MOD13A2", "VNP46A2")
version	character(1). Default is "061", meaning v061.
nasa_earth_data_token	character(1). Token for downloading data from NASA. Should be set before trying running the function.
date	character(1 or 2). length of 10. Date or start/end dates for downloading data. Format "YYYY-MM-DD" (ex. January 1, 2018 = "2018-01-01"). Note: ignored if product == "MOD06_L2".
extent	numeric(4). Bounding box for downloading data. Format is c(min_lon, max_lon, min_lat, max_lat). Default is c(-125, 22, -64, 50), approximately covering the continental United States.
directory_to_save	character(1). Directory to save data.
acknowledgement	logical(1). By setting TRUE the user acknowledges that the data downloaded using this function may be very large and use lots of machine storage and memory.
download	logical(1). Download data or only save wget commands.
remove_command	logical(1). Remove (TRUE) or keep (FALSE) the text file containing download commands.
hash	logical(1). By setting TRUE the function will return an rlang::hash_file() hash character corresponding to the downloaded files. Default is FALSE.

Value

• For hash = FALSE, NULL

• For hash = TRUE, an rlang::hash_file character.

• HDF (.hdf) files will be stored in year/day_of_year sub-directories within directory_to_save.

Note

Due to NASA data access policies, the download scripts generated by this function require a valid NASA Earthdata token for authentication and include options to slow down the download speed to avoid server overload and potential blocking of access.

Both dates in date should be in the same year. Directory structure looks like input/modis/raw/{version}/{product}/{year}/{day_of_year}.

Author(s)

Mitchell Manware, Insang Song

References

\insertRef

data_mcd19a22021amadeus

\insertRef

data_mod06l2_2017amadeus

\insertRef

data_mod09ga2021amadeus

\insertRef

data_mod11a12021amadeus

\insertRef

data_mod13a22021amadeus

\insertRef

article_roman2018vnp46amadeus

Examples

## Not run: 
## NOTE: Examples are wrapped in `/dontrun{}` to avoid sharing sensitive
##       NASA EarthData tokden information.
vec_extent <- c(-80, 35, -75, 40)
# example with MOD09GA product
download_modis(
  product = "MOD09GA",
  version = "061",
  date = "2024-01-01",
  extent = vec_extent,
  nasa_earth_data_token = "./pathtotoken/token.txt",
  directory_to_save = tempdir(),
  acknowledgement = TRUE,
  download = FALSE, # NOTE: download skipped for examples,
  remove_command = TRUE
)
# example with MOD06_L2 product
download_modis(
  product = "MOD06_L2",
  version = "6.1",
  extent = vec_extent,
  date = "2024-01-01",
  nasa_earth_data_token = "./pathtotoken/token.txt",
  directory_to_save = tempdir(),
  acknowledgement = TRUE,
  download = FALSE, # NOTE: download skipped for examples,
  remove_command = TRUE
)
# example with VNP46A2 product
download_modis(
  product = "VNP46A2",
  version = "5200",
  date = "2024-01-01",
  extent = vec_extent,
  nasa_earth_data_token = "./pathtotoken/token.txt",
  directory_to_save = tempdir(),
  acknowledgement = TRUE,
  download = FALSE, # NOTE: download skipped for examples,
  remove_command = TRUE
)

## End(Not run)

amadeus documentation built on Jan. 27, 2026, 1:07 a.m.