plot_raster_smos {smosr}

Draw a raster image of BEC-SMOS soil moisture data

Description

This function draws a raster image of BEC-SMOS soil moisture data corresponding to a single data file and specific geographical extent.

Usage

plot_raster_smos(data, lat = NULL, lon = NULL, QA = NULL)

Arguments

data

a character string containing a link to a single BEC-SMOS data file stored on the local computer.

lat

a numeric vector of length 2 containing latitudinal bounds of the plotting region (in ‘latlon’ projection). Default value is NULL meaning that all data between min and max latitudes are drawn.

lon

a numeric vector of length 2 containing longitudinal bounds of the plotting region (in ‘latlon’ projection). Default value is NULL meaning that all data between min and max longitudes are drawn.

QA

a numeric vector specifying the desired data quality to be plotted. Possible values range from 0 (good quality data) to 15. To know the meanings of QA flags, see Details.

Details

This function reads an original BEC-SMOS soil moisture data file in NetCDF format, converts data from EASE-2 grid cells to geographic coordinates, and draws a raster image of soil moisture estimates in ‘latlon’ projection. The image can be drawn for a specific geographical extent if requested by the user. Otherwise, the entire dataset across Europe (between 28 and 72 degrees north and -11 and 40 degrees east) will be plotted. Note that due to high resolution of the data (~1 km), the execution of this function may take a long time to be completed depending on the amount of data to be drawn.

**** Quality assurance (QA) ****

QA flags are coded by four significant bits as described below:

	--------------	--------------------------------------------------------------------------------
	Bit position	Bit value
	--------------	--------------------------------------------------------------------------------
	[0]	0 - Brightness temperature not affected by sea-land contamination
		1 - Brightness temperature corrected by sea-land contamination
	-------------	--------------------------------------------------------------------------------
	[1]	0 - Radio Frequency Interference (RFI) not flagged in ESA L1C
		brightness temperature
		1 - RFI flagged in ESA L1C brightness temperature
	-------------	--------------------------------------------------------------------------------
	[2]	0 - L3 soil moisture with data obtained from L2 retrievals
		1 - L3 soil moisture with data obtained from a linear model
	-------------	--------------------------------------------------------------------------------
	[3]	0 - L4 soil moisture values within the interval [0,1] m^3/m^3
		1 - L4 soil moisture values outside the interval [0,1] m^3/m^3
	-------------	--------------------------------------------------------------------------------

In case of the 3-day averaged data, each bit of the quality flag is activated if at least one soil moisture estimate during the corresponding time interval is affected.

Value

a raster image

References

Pablos M, Gonzalez-Haro C, Portal G, Piles M, Vall-llossera M, Portabella M (2022). SMOS L4 Surface Soil Moisture downscaled maps at 1 km EASE-2 (reprocessed mode) (V.6.0) [Dataset].

Examples

## Not run: 
# to draw a raster image of soil moisture data corresponding to the first BEC-SMOS file
# from a list produced by list_smos() and within the specified geographical bounds#'
smos_files <- list_smos()
lat <- c(35.00, 45.00)
lon <- c(-10.50, 4.50)
plot_raster_smos(data = smos_files[1], lat = lat, lon = lon)

## End(Not run)