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I'm curious if there is a way to reproject a raster to have 0 as the center longitude rather than 180. I am trying to convert this raster. I've been able to do this in gdal, but I'd like the solution to be in rasterio as it's more pythonic and I also don't think you're supposed to mix the two within one script. I've tried a couple different ways, but I believe the following to be the closest:

import rasterio
from rasterio.warp import reproject

def change_center_long_from_180_to_0(input_fp, output_fp):
    with rasterio.open(input_fp) as src:
        kwargs = src.meta.copy()
        kwargs.update({'CENTER_LONG': 0, 'SOURCE_EXTRA':1000})
        with rasterio.open(output_fp, 'w', **kwargs) as dst:
            for i in range(1, src.count + 1):
                reproject(
                    source=rasterio.band(src, i),
                    destination=rasterio.band(dst, i),
                    src_transform=src.transform,
                    src_crs=src.crs)


return

However, this isn't doing anything to the raster.

Vince
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JWB
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2 Answers2

3

You could try rioxarray: https://gis.stackexchange.com/a/357810

import rioxarray

rds = rioxarray.open_rasterio(input_fp)
rds = rds.assign_coords(x=(((rds.x + 180) % 360) - 180)).sortby('x')
rds.rio.to_raster(output_fp)
snowman2
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0

I have worked with 0-360 data and the easiest method that I have found is in R using rotate from the raster library. I just transformed a geoid file from the NGS that was in 0-360 to 0 centered at Greenwich. See below with function calls and dumps of the CRS info. Note:

  • the shift worked despite the warning thrown in R
  • there are other output types than .asc which generated a larger file than the .bin

'''

    library(raster)
    > dir()[2]
    [1] "g2012bu0.bin"
    > r<-raster(dir()[2])
    > r
    class      : RasterLayer 
    dimensions : 2041, 4201, 8574241  (nrow, ncol, ncell)
    resolution : 0.01666667, 0.01666667  (x, y)
    extent     : 229.9917, 300.0083, 23.99167, 58.00833  (xmin, xmax, ymin, 
    ymax)
    crs        : +proj=longlat +ellps=GRS80 +no_defs 
    source     : g2012bu0.bin 
    names      : g2012bu0

&gt; r2&lt;-rotate(r)
Warning message:
In .local(x, ...) :
  this does not look like an appropriate object for this function

&gt; r2
class      : RasterLayer 
dimensions : 2041, 4201, 8574241  (nrow, ncol, ncell)
resolution : 0.01666667, 0.01666667  (x, y)
extent     : -130.0083, -59.99167, 23.99167, 58.00833  (xmin, xmax, ymin, 
ymax)
crs        : +proj=longlat +ellps=GRS80 +no_defs 
source     : g2012bu0.bin 
names      : g2012bu0 
&gt; writeRaster(r2,'g2012bu0.asc')

'''
Dallon Weathers
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