Ok - just to clear this up and shut down this thread. It turns out it is EPSG:3411 but was reported as 3413. I can import (with -o) into a 3411 location, and then reproject.
Cheers, -k. On Sun, Jul 25, 2021 at 8:45 PM Ken Mankoff <mank...@gmail.com> wrote: > Hi Stefan, > > Thanks for the hint. I often use '-o'. In this case after discussion with > the data provider it turns out that it was not EPSG:3413 but instead some > custom projection, even though part of the NetCDF file reported EPSG:3413 > in the metadata. > > Unfortunately r.import does not work. I get the errors below. Given the > 0..3..6..9... it appears to import something, but no raster exists when the > command finishes. > > r.import input=NetCDF:file.nc:surface output=surface > WARNING: Datum <unnamed> not recognised by GRASS and no parameters found > WARNING: Projection of dataset does not appear to match current location. > > Location PROJ_INFO is: > name: WGS 84 / NSIDC Sea Ice Polar Stereographic North > datum: wgs84 > ellps: wgs84 > proj: stere > lat_0: 90 > lat_ts: 70 > lon_0: -45 > x_0: 0 > y_0: 0 > no_defs: defined > init: EPSG:3413 > > Dataset PROJ_INFO is: > name: unnamed > a: 6378273 > es: 0.006693883000000017 > proj: stere > lat_0: 90 > lat_ts: 70 > lon_0: -45 > x_0: 0 > y_0: 0 > no_defs: defined > > ERROR: datum > > WARNING: Datum <unnamed> not recognised by GRASS and no parameters found > WARNING: Datum <unnamed> not recognised by GRASS and no parameters found > Importing raster map <surface>... > > 0..3..6..9..12..15..18..21..24..27..30..33..36..39..42..45..48..51..54..57..60..63..66..69..72..75..78..81..84..87..90..93..96..99..100 > ERROR: Unable to open element file <windows> for > <tmp.r.import.3257873@PERMANENT> > ERROR: Unable to get reprojected map extent > > > -k. > > > > On Sat, Jul 24, 2021 at 2:19 PM Stefan Blumentrath < > stefan.blumentr...@nina.no> wrote: > >> Hei Ken, >> >> Did you try the -o flag ("Override projection check (use current >> location's projection) >> Assume that the dataset has same projection as the current location")? >> https://grass.osgeo.org/grass78/manuals/r.external.html >> As the error message suggests? >> >> If you are sure that projections in fact match, a mismatch in CRS >> description can be overridden that way, without modifying the input file. >> >> Alternatively, you can use r.import to reproject while converting to >> GRASS format or you create a new location... >> >> Cheers >> Stefan >> >> >> -----Original Message----- >> From: grass-user <grass-user-boun...@lists.osgeo.org> On Behalf Of Ken >> Mankoff >> Sent: fredag 23. juli 2021 19:33 >> To: GRASS user list <grass-user@lists.osgeo.org> >> Subject: [GRASS-user] Cannot read NetCDF with 'semi_major_axis' or >> 'inverse_flattening' >> >> Hello list, >> >> I have been given an updated NetCDF file - everything is the same as the >> old version except there are two new attributes in the 'mapping' variable: >> >> char mapping ; >> mapping:geoid = "eigen-6c4" ; >> mapping:grid_mapping_name = "polar_stereographic" ; >> mapping:latitude_of_projection_origin = 90. ; >> mapping:standard_parallel = 70. ; >> mapping:straight_vertical_longitude_from_pole = -45. ; >> mapping:semi_major_axis = 6378273. ; >> mapping:inverse_flattening = 298.27940504282 ; >> mapping:false_easting = 0. ; >> mapping:false_northing = 0. ; >> mapping:_Storage = "contiguous" ; >> >> >> Specifically: >> mapping:semi_major_axis = 6378273. ; >> mapping:inverse_flattening = 298.27940504282 ; >> >> When I try to load this file with: >> >> r.external source=netCDF:file.nc:surface output=surface >> >> I get this error: >> >> WARNING: Datum <unnamed> not recognised by GRASS and no parameters found >> ERROR: Projection of dataset does not appear to match current location. >> >> Location PROJ_INFO is: >> name: WGS 84 / NSIDC Sea Ice Polar Stereographic North >> datum: wgs84 >> ellps: wgs84 >> proj: stere >> lat_0: 90 >> lat_ts: 70 >> lon_0: -45 >> x_0: 0 >> y_0: 0 >> no_defs: defined >> init: EPSG:3413 >> >> Dataset PROJ_INFO is: >> name: unnamed >> a: 6378273 >> es: 0.006693883000000017 >> proj: stere >> lat_0: 90 >> lat_ts: 70 >> lon_0: -45 >> x_0: 0 >> y_0: 0 >> no_defs: defined >> >> ERROR: datum >> >> In case of no significant differences in the projection definitions, use >> the -o flag to ignore them and use current location definition. >> Consider generating a new location from the input dataset using the >> 'location' parameter. >> >> >> If I remove thos two attributes (semi_major_axis and inverse_flattening) >> with: >> >> ncatted -O -h -a semi_major_axis,mapping,d,l,6378273 -a >> inverse_flattening,mapping,d,f,298.27940504282 file.nc foo.nc >> >> And then try to read in the data, it works. >> >> Is there some reason that those two attributes make it difficult to load >> the data in GRASS? Is there a better work-around than removing them? The >> documented projection of the data has not changed, only some of the >> metadata. >> >> Versions: >> gdal 3.0.4 >> grass 7.8.2 >> >> Thank you, >> >> -k. >> >> _______________________________________________ >> grass-user mailing list >> grass-user@lists.osgeo.org >> >> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.osgeo.org%2Fmailman%2Flistinfo%2Fgrass-user&data=04%7C01%7C%7C900b853648c545edd6fd08d94dffe4cb%7C6cef373021314901831055b3abf02c73%7C0%7C0%7C637626583719044920%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=wWKyBuAKwbuobSGVQ6q97VXj1OIiCLSN9NlbXDLw7tc%3D&reserved=0 >> >
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