Save raster to USGS DEM Format in R

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I would like to know how to do the reverse and save an .img raster image into a USGS DEM format.

Based on GDAL docs, it seems like it would be possible but when I run rgdal::getGDALDriverNames() in R I get the following:

name       long_name                                                            create  copy isRaster
139         USGSDEM                          USGS Optional ASCII DEM (and CDED)  FALSE  TRUE     TRUE

which seems to imply that it won't create these files?

I was hoping to do something like:

library(raster)

# read
img <- raster("Raster_100ft_2022_10_18.img")

# convert to DEM
writeRaster(img, 'test.dem')

But raster doesn't seem to recognize that output format.

Is there some other method to save as USGS DEM files? Thanks

Solution

For me it works with terra. If that's proper "USGSDEM" file, that's another question. From gdal reference it should save the file as well: https://gdal.org/drivers/raster/usgsdem.html

f <- system.file("ex/elev.tif", package="terra")
r <- terra::rast(f)
terra::writeRaster(r, filename = "test.dem", filetype = "USGSDEM", overwrite = TRUE)

raster::raster("test.dem")
#> class      : RasterLayer 
#> dimensions : 90, 95, 8550  (nrow, ncol, ncell)
#> resolution : 0.008333333, 0.008333333  (x, y)
#> extent     : 5.741667, 6.533333, 49.44167, 50.19167  (xmin, xmax, ymin, ymax)
#> crs        : +proj=longlat +datum=WGS84 +no_defs 
#> source     : test.dem 
#> names      : elevation 
#> values     : 141, 547  (min, max)

^{Created on 2022-10-20 with reprex v2.0.2}