Hi,
I have a boundary located near the Portugal/Spain border that I wish to clip some SRTM data to. The boundary was supplied in ED 1950 UTM 29, whilst I also have a point file in the same projection so would ideally like to continue working in this projection. I am having a problem with clipping and reprojecting the SRTM data from WGS84 into ED 1950.
I have attempted a few methods which yield different results where the output rasters show a shift of nearly 200m.
Originally I simply opened the WGS84 directly into the ED1950 data frame and let it project on the fly (using the default ED_1950_To_WGS_1984_41_Ntv2_Spain_v2 transformation) before using the clip raster tool.
Out of curiosity i also tried a second method of projecting the boundary to WGS1984 (so that it would match the SRTM data), clipping the raster (again using clip raster tool) then using the 'project raster' tool with the same transformation as mentioned. However when this clipped and reprojected raster is added to the ED1950 data frame there is an obvious difference between the alignment.
How do I know which is the correct method of reprojecting the data?
I have a boundary located near the Portugal/Spain border that I wish to clip some SRTM data to. The boundary was supplied in ED 1950 UTM 29, whilst I also have a point file in the same projection so would ideally like to continue working in this projection. I am having a problem with clipping and reprojecting the SRTM data from WGS84 into ED 1950.
I have attempted a few methods which yield different results where the output rasters show a shift of nearly 200m.
Originally I simply opened the WGS84 directly into the ED1950 data frame and let it project on the fly (using the default ED_1950_To_WGS_1984_41_Ntv2_Spain_v2 transformation) before using the clip raster tool.
Out of curiosity i also tried a second method of projecting the boundary to WGS1984 (so that it would match the SRTM data), clipping the raster (again using clip raster tool) then using the 'project raster' tool with the same transformation as mentioned. However when this clipped and reprojected raster is added to the ED1950 data frame there is an obvious difference between the alignment.
How do I know which is the correct method of reprojecting the data?