Can I use EPSG:25832 and EPSG:32632 interchangably

Question

up until now we have been using EPSG:25832 (UTM Zone 32N) as our standard Coordinate system. Recently however after we aquired a new project area and consequently new software, I have to display data with EPSG:32632. Looking at the definitions, it seems the only difference is between the extents and the Datum. EPSG:25832 is based on the "European_Terrestrial_Reference_System_1989" using the spheroid "GRS 1980" and EPSG:32632 uses the datum "WGS_1984" with the spheroid of the same name - This means the Semi-major axis are the same but the Semi-minor axis has a difference of 2 meters. All other parameters are the same.

So now the question....can I use them interchangeably on a regional scale? meaning I will not be using them to control satellite systems or aircraft flight paths.

Answer 1

The EPSG registry describes the two CRS as very similar and in some areas interchangeable. In "Area of use" section:

EPSG: 32632. Between 6 ° E and 12 ° E, northern hemisphere between equator and 84 ° N, onshore and offshore. Algeria. Austria. Cameroon. Denmark. Equatorial Guinea. France. Gabon. Germany. Italy. Libya. Liechtenstein. Monaco. Netherlands. Niger. Nigeria. Norway. Sao Tome and Principe. Svalbard. Sweden. Switzerland. Tunisia. Vatican City State.

EPSG: 25832. Europe between 6 ° E and 12 ° E: Austria; Belgium; Denmark - onshore and offshore; Germany - onshore and offshore; Including Norway - onshore and offshore; Spain - offshore.

So, with regard to Europe, I'd use both systems for regional maps of Austria, Denmark, Germany or Spain; while for parts of Europe such as Italy or Switzerland I'd recommend the EPSG:32632.

For all other non-European areas I'd use always the 32632.

Answer 2

As you discovered, if the difference in Semi-minor axis is not important for your needs you can consider that they are identical systems. And if you use any program that is using Proj4 projection library (GDAL, QGIS etc.) there will be no difference between these two. You can test it yourself with gdaltransform http://www.gdal.org/gdaltransform.html

gdaltransform -s_srs epsg:25832 -t_srs epsg:32632
500000 200000
500000 200000.000006593 0

Answer 3

ETRS89 and WGS84 are not the same, although the differences are minor. Some time-dependent transformations between ITRFyy and ETRF2000 are listed here with the XYZ offsets at the centimeter level.

ETRS/ETRF is plate-bound (to minimize changes in coordinates over time) while WGS84 is tied to ITRF. This occurs in North America too where NAD83 is tied to the North American plate.

For a lot of data you can call them equivalent, but if you're working with centimeter-level data, you should talk to the national mapping agency in the location that the data represents or talk to geodetic surveyor in the area.