The way to work with a LAScatalog is explained in chap 14. The buffer is explained in section 14.7.2.
The default is 50 m buffer so your code is already correct.
To store the raster on disk see section 14.8.2. e.g
opt_output_files(LAS_list) <- paste0("folder/{*}_dtm")
The path must be templated to generate one file per chunk. This is not explicitely mentionned in 14.8.2 but see help("LAScatalog-class")
Output options
The slot
@output_options
contains alist
of options that determine how chunks (the sub-areas that are sequentially processed) are written. By "written" we mean written to files or written in R memory.
output_files
: string. Ifoutput_files = ""
outputs are returned in R. Otherwise, ifoutput_files
is a string the outputs will be written to files. This is useful if the output is too big to be returned in R. A path to a filename template without a file extension (the engine guesses it for you) is expected. When several files are going to be written a single string is provided with a template that is automatically filled. For example, the following file names are possible:
"/home/user/als/normalized/file_{ID}_segmented"
"C:/user/document/als/zone52_{XLEFT}_{YBOTTOM}_confidential"
"C:/user/document/als/{ORIGINALFILNAME}_normalized"
This option will generate as many filenames as needed with custom names for each file. The allowed templates are{XLEFT}
,{XRIGHT}
,{YBOTTOM}
,{YTOP}
,{ID}
,{XCENTER}
,{YCENTER}
,{ORIGNALFILENAME}
. Seeopt_output_files
.