This function searches for SMAP data on a specific date, returning a
data.frame describing available data.
find_smap(id, dates, version)A character string that refers to a specific SMAP dataset, e.g.,
"SPL4SMGP" for SMAP L4 Global 3-hourly 9 km Surface and Rootzone Soil
Moisture Geophysical Data. See "Details" for a list of supported data types
and their associated id codes.
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 seq.Date.
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
A data.frame with the names of the data files, the remote directory, and the date.
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/
if (FALSE) {
# 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)
}