| Title: | Acquisition and Processing of NASA Soil Moisture Active-Passive (SMAP) Data |
|---|---|
| Description: | Facilitates programmatic access to NASA Soil Moisture Active Passive (SMAP) data with R. It includes functions to search for, acquire, and extract SMAP data. |
| Authors: | Maxwell Joseph [aut, cre], Matthew Oakley [aut], Zachary Schira [aut] |
| Maintainer: | Maxwell Joseph <[email protected]> |
| License: | GPL-3 |
| Version: | 0.2.1 |
| Built: | 2024-11-27 03:54:47 UTC |
| Source: | https://github.com/ropensci/smapr |
The smapr package provides a means to discover, acquire, and process NASA Soil Moisture Active Passive (SMAP) data.
Max Joseph [email protected]
This function downloads SMAP data in HDF5 format.
download_smap(files, directory = NULL, overwrite = TRUE, verbose = TRUE)download_smap(files, directory = NULL, overwrite = TRUE, verbose = TRUE)
files |
A |
directory |
A local directory path in which to save data, specified as a
character string. If left as |
overwrite |
TRUE or FALSE: should existing data files be overwritten? |
verbose |
TRUE or FALSE: should messages be printed to indicate that files are being downloaded? |
This function requires a username and password from NASA's Earthdata portal.
If you have an Earthdata username and password, pass them in using the
set_smap_credentials() function.
If you do not yet have a username and password, register for one here: https://urs.earthdata.nasa.gov/
Returns a data.frame that appends a column called
local_dir to the input data frame, which consists of a character
vector specifying the local directory containing the downloaded files.
## Not run: files <- find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) # files[1, ] refers to the first available data file downloads <- download_smap(files[1, ]) ## End(Not run)## Not run: files <- find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) # files[1, ] refers to the first available data file downloads <- download_smap(files[1, ]) ## End(Not run)
Extracts datasets from SMAP data files.
extract_smap(data, name)extract_smap(data, name)
data |
A data frame produced by |
name |
The path in the HDF5 file pointing to data to extract. |
The arguments group and dataset must refer specifically the
group and name within group for the input file, such as can be obtained with
list_smap(). This function will extract that particular dataset,
returning a Raster object.
Returns a SpatRaster object.
## Not run: files <- find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) downloads <- download_smap(files[1, ]) sm_raster <- extract_smap(downloads, name = '/Geophysical_Data/sm_surface') ## End(Not run)## Not run: files <- find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) downloads <- download_smap(files[1, ]) sm_raster <- extract_smap(downloads, name = '/Geophysical_Data/sm_surface') ## End(Not run)
This function searches for SMAP data on a specific date, returning a
data.frame describing available data.
find_smap(id, dates, version)find_smap(id, dates, version)
id |
A character string that refers to a specific SMAP dataset, e.g.,
|
dates |
An object of class Date or a character string formatted as
To search for one specific date, this can be a Date object of length one. To
search over a time interval, it can be a multi-element object of class Date
such as produced by |
version |
Which data version would you like to search for? Version information for each data product can be found at https://nsidc.org/data/smap/data_versions |
There are many SMAP data products that can be accessed with this function.
Currently, smapr supports level 3 and level 4 data products, each of which
has an associated Data Set ID which is specified by the id argument,
described at https://nsidc.org/data/smap/smap-data.html and summarized
below:
SMAP/Sentinel-1 Radiometer/Radar Soil Moisture
Radar Northern Hemisphere Daily Freeze/Thaw State
Radar Global Daily Soil Moisture
Radiometer Global Soil Moisture
Radar/Radiometer Global Soil Moisture
Surface/Rootzone Soil Moisture Analysis Update
Surface/Rootzone Soil Moisture Geophysical Data
Surface/Rootzone Soil Moisture Land Model Constants
Carbon Net Ecosystem Exchange
This function requires a username and password from NASA's Earthdata portal.
If you have an Earthdata username and password, pass them in using the
set_smap_credentials() function.
If you do not yet have a username and password, register for one here: https://urs.earthdata.nasa.gov/
A data.frame with the names of the data files, the remote directory, and the date.
## Not run: # looking for data on one day: find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) # searching across a date range start_date <- as.Date("2015-03-31") end_date <- as.Date("2015-04-02") date_sequence <- seq(start_date, end_date, by = 1) find_smap(id = "SPL4SMGP", dates = date_sequence, version = 4) ## End(Not run)## Not run: # looking for data on one day: find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) # searching across a date range start_date <- as.Date("2015-03-31") end_date <- as.Date("2015-04-02") date_sequence <- seq(start_date, end_date, by = 1) find_smap(id = "SPL4SMGP", dates = date_sequence, version = 4) ## End(Not run)
This function returns a list of the contents of SMAP data files.
list_smap(files, all = TRUE)list_smap(files, all = TRUE)
files |
A |
all |
If TRUE a longer, more detailed list of information on each entry is provided. |
Returns a list of data.frame objects that list the contents
of each data file in files.
## Not run: files <- find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) files <- download_smap(files[1, ]) list_smap(files) list_smap(files, all = TRUE) ## End(Not run)## Not run: files <- find_smap(id = "SPL4SMGP", dates = "2015-03-31", version = 4) files <- download_smap(files[1, ]) list_smap(files) list_smap(files, all = TRUE) ## End(Not run)
To use smapr, users need to provide NASA Earthdata portal credentials. This function allows users to interactively set these credentials via the user's Earthdata username and password.
set_smap_credentials(username, password, save = TRUE, overwrite = FALSE)set_smap_credentials(username, password, save = TRUE, overwrite = FALSE)
username |
A character string of your Earthdata portal username |
password |
A character string of your Earthdata portal password |
save |
Logical: whether to save your credentials to your
.Renviron file (e.g., ~/.Renviron). Previous Earthdata credentials will not
be overwritten unless |
overwrite |
Logical: whether to overwrite previous Earthdata credentials
in your .Renviron file (only applies when |
If you do not yet have a username and password, register for one here: https://urs.earthdata.nasa.gov/
A warning: do not commit your username and password to a public repository! This function is meant to be used interactively, and not embedded within a script that you would share.
A data.frame with the names of the data files, the remote directory, and the date.
## Not run: set_smap_credentials('myusername', 'mypassword') ## End(Not run)## Not run: set_smap_credentials('myusername', 'mypassword') ## End(Not run)