Can someone enlighten me if there is a difference between initializing a CRS object using the EPSG code versus just the +proj string read from a shapefile?
Consider the following objects:
A SpatialPolygonsDataFrame read in from a .shp using readOGR, no additional arguments. I was handed this data.
> itcs[]@proj4string CRS arguments: +proj=utm +zone=17 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0
A lidR tile:
tile<-readLAS(paste("../data/2015/cropped_",fname,sep="")) tile@crs<-CRS("+init=epsg:32617") > tile@crs CRS arguments: +init=epsg:32617 +proj=utm +zone=17 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0
To me, these should have the same coordinate system, that is, they have the same projection, zone, datum, ellipsoid and units. One already had a coordinate system, one was assigned using the EPSG code. When plotted they appear to be misprojected, overlapping, but skewed and non-aligned. I'm trying to track down the source of this misprojection.
Perhaps similar here why is there a difference between using EPSG and using basic code