Advertencia al leer el archivo tif
Recibo la siguiente advertencia mientras leo los datos de cobertura terrestre de Corine en formato tif usando rastero terrapaquete.
R <- raster::raster(CLC_Tiff)
Mensaje de advertencia: En new_CppObject_xp(fields$.module, campos$.pointer, ...): GDAL Mensaje 1: La definición del CRS EPSG:3035 proyectado obtenido de las claves GeoTIFF no es la misma que la del registro EPSG, que puede causar problemas durante las operaciones de reproyección. Configure la opción de configuración GTIFF_SRS_SOURCE en EPSG para usar parámetros oficiales (anulando los de las claves GeoTIFF), o en GEOKEYS para usar valores personalizados de las claves GeoTIFF y eliminar el código EPSG.
Aquí está la proyección.
raster::projection(R)
[1] "+proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 +ellps=GRS80 +units=m +no_defs"
De manera similar para terra:
R <- terra::rast(CLC_Tiff, crs = "EPSG:3035")
Warning message:
In new_CppObject_xp(fields$.module, fields$.pointer, ...) :
GDAL Message 1: The definition of projected CRS EPSG:3035 got from GeoTIFF keys is not the same as the one from the EPSG registry, which may cause issues during reprojection operations. Set GTIFF_SRS_SOURCE configuration option to EPSG to use official parameters (overriding the ones from GeoTIFF keys), or to GEOKEYS to use custom values from GeoTIFF keys and drop the EPSG code.
terra::crs(R)
[1] "PROJCRS[\"ETRS89-extended / LAEA Europe\",\n BASEGEOGCRS[\"ETRS89\",\n DATUM[\"European Terrestrial Reference System 1989\",\n ELLIPSOID[\"GRS 1980\",6378137,298.257222101004,\n LENGTHUNIT[\"metre\",1]]],\n PRIMEM[\"Greenwich\",0,\n ANGLEUNIT[\"degree\",0.0174532925199433]],\n ID[\"EPSG\",4258]],\n CONVERSION[\"Lambert Azimuthal Equal Area\",\n METHOD[\"Lambert Azimuthal Equal Area\",\n ID[\"EPSG\",9820]],\n PARAMETER[\"Latitude of natural origin\",52,\n ANGLEUNIT[\"degree\",0.0174532925199433],\n ID[\"EPSG\",8801]],\n PARAMETER[\"Longitude of natural origin\",10,\n ANGLEUNIT[\"degree\",0.0174532925199433],\n ID[\"EPSG\",8802]],\n PARAMETER[\"False easting\",4321000,\n LENGTHUNIT[\"metre\",1],\n ID[\"EPSG\",8806]],\n PARAMETER[\"False northing\",3210000,\n LENGTHUNIT[\"metre\",1],\n ID[\"EPSG\",8807]]],\n CS[Cartesian,2],\n AXIS[\"(E)\",east,\n ORDER[1],\n LENGTHUNIT[\"metre\",1]],\n AXIS[\"(N)\",north,\n ORDER[2],\n LENGTHUNIT[\"metre\",1]],\n ID[\"EPSG\",3035]]"
En principio, puedo utilizar suppressWarnings()la función para evitar esta advertencia. Sin embargo, me gustaría 1) saber el motivo de esto; 2) ¿hay alguna manera de evitar esto? y 3) ¿es algo que debería preocuparme para análisis posteriores utilizando paquetes terra/raster/sf?
El problema es que el archivo tiene un CRS que contiene un código EPSG y un montón de parámetros. Estos parámetros no coinciden con los parámetros del mismo código EPSG en la base de datos que utiliza GDAL.
Aquí hay una comparación que muestra que son bastante diferentes en cuanto a los caracteres utilizados.
terra::gdal()
#[1] "3.7.2"
terra::crs("EPSG:3035")
# [1] "PROJCRS[\"ETRS89-extended / LAEA Europe\",\n BASEGEOGCRS[\"ETRS89\",\n ENSEMBLE[\"European Terrestrial Reference System 1989 ensemble\",\n MEMBER[\"European Terrestrial Reference Frame 1989\"],\n MEMBER[\"European Terrestrial Reference Frame 1990\"],\n MEMBER[\"European Terrestrial Reference Frame 1991\"],\n MEMBER[\"European Terrestrial Reference Frame 1992\"],\n MEMBER[\"European Terrestrial Reference Frame 1993\"],\n MEMBER[\"European Terrestrial Reference Frame 1994\"],\n MEMBER[\"European Terrestrial Reference Frame 1996\"],\n MEMBER[\"European Terrestrial Reference Frame 1997\"],\n MEMBER[\"European Terrestrial Reference Frame 2000\"],\n MEMBER[\"European Terrestrial Reference Frame 2005\"],\n MEMBER[\"European Terrestrial Reference Frame 2014\"],\n ELLIPSOID[\"GRS 1980\",6378137,298.257222101,\n LENGTHUNIT[\"metre\",1]],\n ENSEMBLEACCURACY[0.1]],\n PRIMEM[\"Greenwich\",0,\n ANGLEUNIT[\"degree\",0.0174532925199433]],\n ID[\"EPSG\",4258]],\n CONVERSION[\"Europe Equal Area 2001\",\n METHOD[\"Lambert Azimuthal Equal Area\",\n ID[\"EPSG\",9820]],\n PARAMETER[\"Latitude of natural origin\",52,\n ANGLEUNIT[\"degree\",0.0174532925199433],\n ID[\"EPSG\",8801]],\n PARAMETER[\"Longitude of natural origin\",10,\n ANGLEUNIT[\"degree\",0.0174532925199433],\n ID[\"EPSG\",8802]],\n PARAMETER[\"False easting\",4321000,\n LENGTHUNIT[\"metre\",1],\n ID[\"EPSG\",8806]],\n PARAMETER[\"False northing\",3210000,\n LENGTHUNIT[\"metre\",1],\n ID[\"EPSG\",8807]]],\n CS[Cartesian,2],\n AXIS[\"northing (Y)\",north,\n ORDER[1],\n LENGTHUNIT[\"metre\",1]],\n AXIS[\"easting (X)\",east,\n ORDER[2],\n LENGTHUNIT[\"metre\",1]],\n USAGE[\n SCOPE[\"Statistical analysis.\"],\n AREA[\"Europe - European Union (EU) countries and candidates. Europe - onshore and offshore: Albania; Andorra; Austria; Belgium; Bosnia and Herzegovina; Bulgaria; Croatia; Cyprus; Czechia; Denmark; Estonia; Faroe Islands; Finland; France; Germany; Gibraltar; Greece; Hungary; Iceland; Ireland; Italy; Kosovo; Latvia; Liechtenstein; Lithuania; Luxembourg; Malta; Monaco; Montenegro; Netherlands; North Macedonia; Norway including Svalbard and Jan Mayen; Poland; Portugal including Madeira and Azores; Romania; San Marino; Serbia; Slovakia; Slovenia; Spain including Canary Islands; Sweden; Switzerland; Türkiye (Turkey); United Kingdom (UK) including Channel Islands and Isle of Man; Vatican City State.\"],\n BBOX[24.6,-35.58,84.73,44.83]],\n ID[\"EPSG\",3035]]"
terra::crs(R)
#[1] "PROJCRS[\"ETRS89-extended / LAEA Europe\",\n BASEGEOGCRS[\"ETRS89\",\n DATUM[\"European Terrestrial Reference System 1989\",\n ELLIPSOID[\"GRS 1980\",6378137,298.257222101004,\n LENGTHUNIT[\"metre\",1]]],\n PRIMEM[\"Greenwich\",0,\n ANGLEUNIT[\"degree\",0.0174532925199433]],\n ID[\"EPSG\",4258]],\n CONVERSION[\"Lambert Azimuthal Equal Area\",\n METHOD[\"Lambert Azimuthal Equal Area\",\n ID[\"EPSG\",9820]],\n PARAMETER[\"Latitude of natural origin\",52,\n ANGLEUNIT[\"degree\",0.0174532925199433],\n ID[\"EPSG\",8801]],\n PARAMETER[\"Longitude of natural origin\",10,\n ANGLEUNIT[\"degree\",0.0174532925199433],\n ID[\"EPSG\",8802]],\n PARAMETER[\"False easting\",4321000,\n LENGTHUNIT[\"metre\",1],\n ID[\"EPSG\",8806]],\n PARAMETER[\"False northing\",3210000,\n LENGTHUNIT[\"metre\",1],\n ID[\"EPSG\",8807]]],\n CS[Cartesian,2],\n AXIS[\"(E)\",east,\n ORDER[1],\n LENGTHUNIT[\"metre\",1]],\n AXIS[\"(N)\",north,\n ORDER[2],\n LENGTHUNIT[\"metre\",1]],\n ID[\"EPSG\",3035]]"
Pero eso en sí mismo no significa que el CRS sea significativamente diferente.
No veo ninguna diferencia si hago:
library(terra)
v <- vect(system.file("ex/lux.shp", package="terra"))
x <- project(v, "EPSG:3035")
y <- project(v, crs(R))
plot(x)
lines(y, col="red")
