TransDEM Forum

There can be several reasons, not so easy to say.

Is your project a large one? Many map images loaded? TransDEM may run out of memory when exporting large projects. In this case reduce the number of map images loaded and export smaller sections of your route. You can always merge in Trainz Surveyor as baseboards created by TransDEM retain a static mapping to UTM coordinates.

Yes the project is quite large, but i selected a smaller area and thought it's going to be ok like that. I will try to load fewer images and see what is going on

Old case and now it happened to me...

My country, Indonesia had GEOTIFF 0.27sec arc with vertical datum EGM2008 and in few months will upgraded to EGM2020.
Few weeks ago, I had download them for about 240 files TIF.

But because TRANSDEM didn't accept EGM2008. I start to convert it to WGS84 via QGIS then converted to DEM via TRANSDEM 2.6.6 then try it.
file size TIFF version = 44MB and DEM version = 30MB each files.
First week it's OK, normal operation as ussual.

Because 240 files it enough uuurghhh one by one file, I try to merge before loaded to TRANSDEM....
I saw TaskManager, memory is full 99% (32 gigs installed). I cancelled merged operation.

THEN,
After load first DEM, TRANSDEM will fail to ADD MORE DEM... Always "DEM OPERATION ABORTED" although I close again program and restart windows...
UNTIL NOW.

Could some one have solve this problem ?
Thanks in advance ..

You say you cannot add a second DEM to the first one. Can you load that second DEM alone? How big is each of them now? I understand your merged quite a few of your smaller ones into a bigger one. All .dem files saved by TransDEM are UTM/WGS84 and allocated to an UTM zone. Are both DEMs in question in the same UTM zone?

A merge operation will allocate lots of additional memory for temporary use. With very large DEMs this can easily exceed available main memory, even on systems that have are reasonably equipped. I managed to exhaust the 64GB I have on my current system.


For TransDEM purposes, the EGM doesn't really matter, we are not that accurate here . However, reference ellipsoids and datums, based on newer EGMs, tend to get new EPSG codes. TransDEM defines several EPSG codes as "aliases" to be mapped to WGS84, but certainly not every possible one. Can you point me to your geo data source - I guess data is publicly available and free of charge? - and to information of the underlying spatial reference system?

TransDEM has quite a few users in Indonesia and direct support for Indonesian geo data might be welcome.

Sorry for my incomplete information...

After I realized that there was a memory problem, I canceled to load merged TIF in TRANSDEM and back to "normal" procedure : one-by-one TIF file again to convert TIF to DEM.


Yeah, before merged, original TIF size is about 44MBs and DEM size is about 30MBs.
After TIF merged is about 2GBs size. But I had cancelled all this merged TIF.

ONLY first TIF or DEM file can load in TRANSDEM. But second DEM will got "DEM Operation aborted" on random DEM file.

Here link about Indonesian DEM :
https://tanahair.indonesia.go.id/demnas

Here link of sample what I donwloaded and translated to WGS84 EPSG:4326
https://drive.google.com/drive/folders/ ... sp=sharing