I have an issue that is driving me crazy that I just can't figure out for the life of me. I'm processing large Sentinel-2 tiles and attempting to use terra::mosaic() to put them together. I start with two SpatRasters, notice how the min-max values differ for each band:
> sent1
class : SpatRaster
dimensions : 10980, 10980, 7 (nrow, ncol, nlyr)
resolution : 10, 10 (x, y)
extent : 399960, 509760, 6290220, 6400020 (xmin, xmax, ymin, ymax)
coord. ref. : WGS 84 / UTM zone 9N (EPSG:32609)
source : T09VVD_2022_mean.tif
names : B02, B03, B04, B05, B06, B07, ...
min values : 0, 0, 29, 379.8125, 523.3125, 385.875, ...
max values : 10456, 9464, 15768, 13930.6875, 15912.1250, 16714.938, ...
> sent2
class : SpatRaster
dimensions : 10980, 10980, 7 (nrow, ncol, nlyr)
resolution : 10, 10 (x, y)
extent : 399960, 509760, 6390240, 6500040 (xmin, xmax, ymin, ymax)
coord. ref. : WGS 84 / UTM zone 9N (EPSG:32609)
source : T09VVE_2022_mean.tif
names : B02, B03, B04, B05, B06, B07, ...
min values : 0, 211, 1, 379.125, 331.3125, 342.75, ...
max values : 9104, 8448, 10480, 12210.500, 16052.9375, 16814.38, ...
Now see how all bands have the same values:
sent3 <- mosaic(sent1, sent2)
> show(sent3)
class : SpatRaster
dimensions : 20982, 10980, 7 (nrow, ncol, nlyr)
resolution : 10, 10 (x, y)
extent : 399960, 509760, 6290220, 6500040 (xmin, xmax, ymin, ymax)
coord. ref. : WGS 84 / UTM zone 9N (EPSG:32609)
source : spat_fubTXtzTOH0dho5_70406.tif
names : B02, B03, B04, B05, B06, B07, ...
min values : 355.6161, 355.6161, 355.6161, 355.6161, 355.6161, 355.6161, ...
max values : 12130.0361, 12130.0361, 12130.0361, 12130.0361, 12130.0361, 12130.0361, ...
When I try to plot it in R or QGIS all the bands look the same which is obviously not the desired output.
I have also tried to add the files to a SpatRasterCollection and mosaic that but it had the same results:
sent.sprc <- sprc(sent1, sent2)
sent4 <- mosaic(sent.sprc)
> show(sent4)
class : SpatRaster
dimensions : 20982, 10980, 7 (nrow, ncol, nlyr)
resolution : 10, 10 (x, y)
extent : 399960, 509760, 6290220, 6500040 (xmin, xmax, ymin, ymax)
coord. ref. : WGS 84 / UTM zone 9N (EPSG:32609)
source : spat_hDQlRCrwBUOApYB_49105.tif
names : B02, B03, B04, B05, B06, B07, ...
min values : 355.6161, 355.6161, 355.6161, 355.6161, 355.6161, 355.6161, ...
max values : 12130.0361, 12130.0361, 12130.0361, 12130.0361, 12130.0361, 12130.0361, ...
However, merge() works and produces the desired output:
sent5 <- merge(sent1, sent2)
> show(sent5)
class : SpatRaster
dimensions : 20982, 10980, 7 (nrow, ncol, nlyr)
resolution : 10, 10 (x, y)
extent : 399960, 509760, 6290220, 6500040 (xmin, xmax, ymin, ymax)
coord. ref. : WGS 84 / UTM zone 9N (EPSG:32609)
source : spat_fqpzxaTDk0yKNGb_50974.tif
names : B02, B03, B04, B05, B06, B07, ...
min values : 0, 0, 1, 379.125, 331.3125, 342.75, ...
max values : 10456, 9464, 15768, 13930.688, 16052.9375, 16814.38, ...
Overall I am working with several files that are all quite large so I'm running on an HPC. I transferred two of the files to my local machine to test it out and it's the same problem. I have the current development version of Terra installed and only have 'terra' and 'here' packages loaded. I tried to make a reproducible example but couldn't figure out how to generate dummy data for the multiband raster. If you have any suggestions please let me know! I can supply two of the sentinel-files if that helps but they are >3gb each.
