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I downloaded DEM infomation from GISDepot and it uses NAD27 as the Datum. What I was wondering is if I brought the DEM's into MicroDEM with the Primary Datum set as WGS84, is there a way to convert them to the WGS84 Datum. Or do you know of any other way to do this?The reason I'm asking is the Topo maps I'm using as a reference guide are in WGS84 Datum format. And I know both DEMEX and MSTS assume that the Datum is WGS84, but I can't figure out how to convert the DEM information before I bring it into DEMEX.Also, if anyone else besides JohnCS knows the answer, please feel free to reply. Thanks for the help.Mike
Lawrence, I already read that thread, but I still wasn't clear as to the conversion process. They mentioned offseting the marker file instead of converting the DEM information. But JohnCS mantioned something about loading the DEM into MicroDEM with the default Datum set to WSG84. When I tried this all that happened was the lon/lat cordinates displayed on the status bar were adjusted properly, but the original DEM file remains in the NAD27 format. So I'm not clear has to how it can be converted. I tried saving it as a MD DEM file, but that was still in the NAD27 Datum format, so it wasn't property converted. So I was just looking for some clarification. Or maybe it's not possible and if that's the case I was going to try and write a utility to convert the data, but didn't want to start that if there is already such a way to perform the conversion. Anyway, thanks for replying with the link to the thread.Mike
If you create your terrain with DEMEX without trying any of the hacks that JohnCS mentioned in the other post, the terrain will be WSG84. Markers, map images, anything else of the sort will have to be in WSG84 to align with the terrain. If you have location information in NAD27 you will have to shift it to align with the WSG84 terrain.David Beach.
David, I think that answers my question, so if I'm understanding you correctly, if I use DEMEX and load a SDTS DEM that was created with NAD27 Datum, when DEMEX creates the MSTS terrian it will detect the NAD27 and apply the Datum shift to WSG84 automatically? Resulting in a MSTS terrain that is properly aligned for WSG84? If this is the case, thats exactly what I want. Cause I'm going to be using DeLorme TopoUSA as my reference maps.I miss understood the other thread that Lawrence posted earlier. And the other thing that screwed me up was I thought I had everything aligned right the first time cause the DEM was NAD27 and I started out with Topozone which is also in NAD27 format. Then I read that thread and wasn't sure if I was doing it right (Which ended up being that I did screw up, lol). So I started looking around for maps that provided WSG84 Datum cordinates and just wanted to make sure my Terrain would be properly aligned.Ok, now after I seriously confused myself, I'm back on track Thanks for the help and sorry if I confused anyone else in the process.Mike
You've got it.I wish that I had been able to generate my terrain in NAD27 simply because I am using USGS DRGs as my base maps (see old thread http://www.train-sim.com/dcforum/DCForumID6/5468.html ). But now I've gotten far enough that I don't want to start over again, so I just have to shift all my base map images from NAD27 to WSG84.Anybody using a source of positioning information that is already in WSG84 (or NAD83) is certainly better off with the situation the way it is.David Beach.