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I have an ASCII grid file that has rectangular cells. The ESRI documentation does not specify how to convert from .asc to raster with a DX/DY value such that:
NCOLS 1900
NROWS 1100
XLLCORNER 115.834717
YLLCORNER 31.638744
XCELLSIZE ...
YCELLSIZE ...
NODATA_VALUE 0
I do not want to read into a NumPy array. So how would one do this, be it manually, in ArcGIS?
I suggest three steps workflow; (1) Edit header, (2) Import the file, and (3) Georeference it to its proper extent.
(1) Edit the header (XLLCORNER, YLLCORNER, CELLSIZE) to a dummy extent
NCOLS 1900
NROWS 1100
XLLCORNER 0.0
YLLCORNER 0.0
CELLSIZE 1
NODATA_VALUE 0
(2) Read this file by Ascii to Raster
(3) Georeference it by Warp
Source
0 0
1900 0
0 1100
1900 1100
Target
115.834717 31.638744
115.834717 + XCELLSIZE * 1900 31.638744
115.834717 31.638744 + YCELLSIZE * 1100
115.834717 + XCELLSIZE * 1900 31.638744 + YCELLSIZE * 1100
Above calculation comes from:
xLR= XLLCORNER + XCELLSIZE * NCOLS
yUL= YLLCORNER + YCELLSIZE * NROWS
