hdf_extract: hdf_extract

In RichardLemoine/LSTtools: LSTtools: An R package to process thermal data derived from Landsat and MODIS images

Description

Extract and scale MODIS layers from a .hdf MODIS LST or vegetation index product as downloaded from NASA EarthExplorer.

Usage

hdf_extract(x, dest = getwd(), conv = TRUE)

Arguments

x	.hdf MODIS file.
dest	Path or folder to export the extracted bands.
conv	Logical; if TRUE, temperature units are converted to Celsius degrees.

Details

Extract MODIS layers from a .hdf MODIS product retaining the product name, acquisition date, tile identifier, collection version and julian date of production in the output name. The extraction of names is suited specifically for vegetation indices (MXD13) and LST and Emissivity (MXD11) MODIS products as downloaded from NASA EarthExplorer. Products MXD11_L2 and MXD21_L2 are not supported. The function scales the values of each band. If parameter conv = TRUE, temperature units are converted to Celsius degrees for LST bands. This is the default.

A negative sign of the viewing angle in MXD11 products means MODIS viewing the grid from east. The view zenith angle itself is always a positive number, the zenith angle from nadir. The information of MODIS viewing the grid from east or west may be important in understanding the view angle effect in the temporal variations in LST, especially in rugged regions.

Value

Exported .tif layers.

References

https://earthexplorer.usgs.gov/

Wan, Z. (1999). "MODIS Land-Surface Temperature Algorithm Theoretical Basis Document (LST ATBD) Version 3.3, April 1999".

Wolfe, R.E., D.P. Roy, E. Vermote. (1998). "MODIS land data storage, gridding and compositing methodology: level 2 grid". IEEE Trans. Geosci. Remote Sens., v36, n4, pp. 1324-1338.

Examples

## Not run: # For MOD11A2 LST product saving .tif bands in a different folder
hdf_extract("MOD11A2.A2019169.h08v07.006.2019178033848.hdf", "C:/MODISLST", conv = TRUE)
## End(Not run)

RichardLemoine/LSTtools documentation built on Oct. 19, 2020, 12:50 a.m.