If the file is already present in
destdir, then it is not
downloaded again. The default
destdir is the present directory,
but it probably makes more sense to use something like
to make it easy for scripts in other directories to use the cached data.
The file is downloaded with
download.amsr( year, month, day, destdir = ".", server = "http://data.remss.com/amsr2/bmaps_v08" )
|year, month, day||
Numerical values of the year, month, and day
of the desired dataset. Note that one file is archived per day,
so these three values uniquely identify a dataset.
A string naming the directory in which to cache the downloaded file.
The default is to store in the present directory, but many users find it more
helpful to use something like
A string naming the server from which data are to be acquired. See “History”.
A character value indicating the filename of the result; if there is a problem of any kind, the result will be the empty string.
Until 25 March 2017, the default server was
"ftp.ssmi.com/amsr2/bmaps_v07.2", but this was changed when the author
discovered that this FTP site had been changed to require users to create
accounts to register for downloads. The default was changed to
"http://data.remss.com/amsr2/bmaps_v07.2" on the named date.
This site was found by a web search, but it seems to provide proper data.
It is assumed that users will do some checking on the best source.
On 23 January 2018, it was noticed that the server-url naming convention
had changed, e.g.
provides daily images going back to 2012. Three-day,
monthly, and monthly composites are also provided on that site.