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f12b574f
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Jim Regetz
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# Code to produce enblended DEM (i.e., using multiresolution splines as
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933632ec
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Jim Regetz
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# described by Burt & Adelson 1983) in the 60N boundary region. After
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# appropriately preparing the SRTM and ASTER layers, this code makes a
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# system call to run 'enblend' (v. 4.0) on the inputs, then
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# post-processes the resulting image to yield a single band geotiff with
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# datatype of 16bit signed integer, matching the input data.
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f12b574f
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Jim Regetz
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#
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933632ec
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Jim Regetz
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# Somewhat arbitrarily, in the code below the input DEMs are prepped
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# such that the area of SRTM/ASTER overlap is the first 75 rows below
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# 60N (i.e., a zone extending ~6.75km south of the boundary).
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f12b574f
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Jim Regetz
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#
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# Jim Regetz
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# NCEAS
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library(raster)
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demdir <- "/home/regetz/media/temp/terrain/dem"
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# read in aster data
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aster <- raster(file.path(demdir, "aster_300straddle.tif"))
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# create alpha layer for aster
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alpha <- aster
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alpha[] <- 0
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alpha[1:225, ] <- 1
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# write enblend-ready tif out to disk
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writeRaster(brick(aster, alpha), file="aster-enblend.tif",
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options="ALPHA=YES")
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# read in srtm
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srtm.lower <- raster("../srtm_150below.tif")
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# expand to match full image (i.e., same extent as aster), holding srtm
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# data below 60N and nothing above
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srtm <- aster
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srtm[] <- NA
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srtm[151:300, ] <- values(srtm.lower)
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# create alpha layer for srtm
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alpha <- srtm
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alpha[] <- 0
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alpha[151:300, ] <- 1
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writeRaster(brick(srtm, alpha), file="srtm-enblend.tif",
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options="ALPHA=YES")
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933632ec
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Jim Regetz
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# run 'enblend'
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f12b574f
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Jim Regetz
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system(paste("enblend --verbose=6 -o enblend.tif",
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"aster-enblend.tif srtm-enblend.tif"))
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# post-process enblended DEM
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e <- raster("enblend.tif")
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e2 <- aster
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933632ec
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Jim Regetz
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# round to nearest integer, and write out the result as a geotiff
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4bc2a9e9
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Jim Regetz
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e2[] <- as.integer(round(values(e), 0))
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f12b574f
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Jim Regetz
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writeRaster(e2, file=file.path(demdir, "fused_300straddle_enblend.tif"),
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options="COMPRESS=NONE", datatype="INT2S")
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