collection: string. mandatory. Collection of interest (see details of mf_get_url ).
roi: object of class sf. mandatory. Area of region of interest. Must be a Simple feature collection with geometry type POLYGON, composed of one or several rows (i.e. one or several ROIs), and with at least two columns: 'id' (an identifier for the roi) and 'geom' (the geometry).
credentials: vector string of length 2 with username and password. optional if the function mf_login was previously executed.
verbose: string. Verbose mode ("quiet", "inform", or "debug"). Default "inform".
Returns
a list with the following named objects :
roiSpatialIndexBound: OPeNDAP indices for the spatial coordinates of the bounding box of the ROI (minLat, maxLat, minLon, maxLon)
availableVariables: Variables available for the collection of interest
roiSpatialBound: The spatial coordinates of the bounding box of the ROI expressed in the CRS of the collection
OpenDAPXVector: The X (longitude) vector
OpenDAPYVector: The Y (longitude) vector
OpenDAPtimeVector: The time vector, or NULL if the collection does not have a time vector
modis_tile: The MODIS tile(s) number(s) for the ROI or NULL if the collection is not MODIS
Details
When it is needed to loop the function mf_get_url over several time frames, it is advised to previously run the function mf_get_opt_param and provide the output as input opt_param parameter of the mf_get_url function. This will save much time, as internal parameters will be calculated only once.
Examples
## Not run:# Login to Earthdatalog <- mf_login(credentials = c("earthdata_un","earthdata_pw"))# Get the optional parameters for the collection MOD11A1.061 and the following roi :roi <- sf::st_as_sf( data.frame( id ="roi_test", geom ="POLYGON ((-5.82 9.54, -5.42 9.55, -5.41 8.84, -5.81 8.84, -5.82 9.54))"), wkt ="geom", crs =4326)opt_param_mod11a1 <- mf_get_opt_param("MOD11A1.061", roi)str(opt_param_mod11a1)# Now we can provide opt_param_mod11a1 as input parameter of the function mf_get_url().time_ranges <- list( as.Date(c("2016-01-01","2016-01-31")), as.Date(c("2017-01-01","2017-01-31")), as.Date(c("2018-01-01","2018-01-31")), as.Date(c("2019-01-01","2019-01-31")))(urls_mod11a1 <- map(.x = time_ranges,~ mf_get_url( collection ="MOD11A1.061", variables = c("LST_Day_1km","LST_Night_1km","QC_Day","QC_Night"), roi = roi, time_range = .x, opt_param = opt_param_mod11a1
)))## End(Not run)