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I am working with two rasters. I am trying to reproject r1 the same way as the raster r2. Rasters are available here

r1

class       : RasterLayer 
dimensions  : 30286, 58025, 1757345150  (nrow, ncol, ncell)
resolution  : 99.99876, 99.99876  (x, y)
extent      : -2893269, 2909160, 224962.6, 3253525  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23 +lon_0=-96 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs +ellps=GRS80 +towgs84=0,0,0 
values      : 0, 7 (min, max)

r2

class       : RasterLayer 
dimensions  : 585, 1386, 810810  (nrow, ncol, ncell)
resolution  : 0.04166599, 0.041666  (x, y)
extent      : 235.207, 292.9561, 25.04224, 49.41686  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +ellps=WGS84 +no_defs 
values      : -7.904284, 12.21496  (min, max)

I precise that the resolution of r1 is 100 m and the resolution of r2 is supposed to be 4km. Moreover, the system of coordinates is different as one is in degree and another one in meter. I would like to reproject the rasters in order they keep their own resolution and share the same extent.

I did not find a way to do it. When I upload my data in Arcgis, the rasters are aligned as I would like which is not the case with Qgis and R. The final goal would be to allow raster calculations by stacking the raster for example.

I do not want to reproject the raster from r2 to r1 as I am working with thousands of raster that have the same coordinates than r2.

I can work with Arcgis, Qgis, and R. However, I do not know how to code in Python.

Currently, by applying the method by Spacedman (answers below), I obtainedthis figure. This is much better as my rasters are closers but there are still not at the same position when I plot them. Moreover, the resolution of r1 has changed. I am confused to what is the problem.

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The extent of r2 is giving problems because its not in the longitude range -180 to 180, but probably 0 to 360:

extent      : 235.207, 292.9561, 25.04224, 49.41686  (xmin, xmax, ymin, ymax)

If you fix that then:

r1p = projectRaster(r1, r2)

will work nicely.

You can fix this by reassigning the extent of a raster to a new extent with the X coordinates minus 360:

> r2
class       : RasterLayer 
dimensions  : 585, 1386, 810810  (nrow, ncol, ncell)
resolution  : 0.04166599, 0.041666  (x, y)
extent      : 235.207, 292.9561, 25.04225, 49.41686  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +ellps=WGS84 +no_defs 
data source : in memory
names       : layer 
values      : 1, 810810  (min, max)

> extent(r2) = extent(xmin(r2)-360, xmax(r2)-360, ymin(r2), ymax(r2))
> r2
class       : RasterLayer 
dimensions  : 585, 1386, 810810  (nrow, ncol, ncell)
resolution  : 0.04166602, 0.04166602  (x, y)
extent      : -124.793, -67.0439, 25.04224, 49.41686  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +ellps=WGS84 +no_defs 
data source : in memory
names       : layer 
values      : 1, 810810  (min, max)
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  • Thank you for your comments. However, it improves a lot. However, how could I have my rasters like superposed? Currently it improves a lot the reproduction but they are not displayed at the same location. And do you know how I could use projectRaster in a way r1 does not change its spatial resolution (keep it to 100, 100)? Thanks in advance!
    – LMontef
    Commented May 12, 2019 at 21:57
  • You need to create a 100x100 raster that covers the projected extent of the source raster. However I'm not sure I really understand the rest of your comment. Perhaps if you edited your question and included some maps that would improve things.
    – Spacedman
    Commented May 12, 2019 at 22:18

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