DEM Boundary Coordinates

[scubakobe]

Hello All,

I have sucessfully converted an SDTS data file to DEM. Now I am working on creating a .INF file for use with converting the DEM for use in FS2004. After reading through the Terrain SDK information, it says I need the coordinates of the bounding area of the DEM. I don't know how to find these coordinates though.

It looks like I only need the north western corner coordinates though.

Also, about the "ScaleInMeters" section of the INF file, in the example it shows:

SourceFile= "dem_100m_mtrainier.dat"
ScaleinMeters= 1.0

So, if my DEM has a resolution of 10M, the Scale should be 0.1?



Thanks for the help!

 

[rhumbaflappy]

Hi scub.

ScaleInMeters refers to the elevation, not the distance between samples. Almost all "z" values in dem data are expressed as meters.

It's in the fs2000 terrain SDK.

Dick

 

[scubakobe]

Thanks for the clarification, Dick.

So far I have this .INF file in the works:

[Source]
	Type			= ElevS16LSB
	SourceDir		= "xxxx Set Already"
	SourceFile		= "sutherlin_dem.dem"
	[B]Lat[/B]			= 46.99916666667
	[B]Lon[/B]			= -121.9466666667
	[B]NumOfCellsPerLine[/B] = 457
	[B]NumOfLines[/B]		= 375
	CellXdimensionDeg = 0.0008333333333333
	CellYdimensionDeg = 0.0008333333333332
	ScaleinMeters	= 1.0

Neither the FS2000 SDK or FS2004 SDK provide information on how to acquire the Lat, Lon, NumOfCellsPerLine, or NumOfLines.

Is there a program that will do this work for me, or is this all manual and no automation?

Thanks,
Kobbe

 

[rhumbaflappy]

Hi Kobbe.

Yes, the lat and long are the northwest corner. The number of cells per line is the east-west width of the data in "words". The number of lines is just that.

By "words" I mean that most dem data is 2 bytes in size. The STDS data should have a meta data description of the width and number of lines.

Dick

 

[scubakobe]

Hi Kobbe.

Yes, the lat and long are the northwest corner. The number of cells per line is the east-west width of the data in "words". The number of lines is just that.

By "words" I mean that most dem data is 2 bytes in size. The STDS data should have a meta data description of the width and number of lines.

Dick

The way I got the STDS file was downloading a TAR file, extracting the STDS file from it, then extracting it further to get multiple .DDF files. Along with those DDF files came a README that doesn't have any information on the STDS file itself.
Is there another way to find that out? I might be looking at the wrong thing too, this is my first time trying to create a mesh.

After using a conversion tool to make the DDF files in to a DEM, I got a DEM file of the size of 8.93 MB. That's a lot more than 2 bytes! Did I do something wrong?

 

[rhumbaflappy]

using a conversion tool to make the DDF files in to a DEM, I got a DEM file of the size of 8.93 MB. That's a lot more than 2 bytes! Did I do something wrong?

Not at all. The 2-byte word is the elevation of each "cell". How did yoiu determine the number of cells per line? or the number of lines? If you are assured these are right, then your inf should compile without problems.

I only meant to tell you the ScaleInMeters refers to the elevation of the cells. The default is 1.0 and it does not need to be written in the inf unless it is not 1.0 meters.

Dick

 

[scubakobe]

OH!

I just took the sample INF from the SDK and edited a couple things to suit mine, but I didn't edit the cells per line or number of lines, that's default from the example.

Where can I get that information then?
So when you said "2-bytes", you mean each individual DDF file. I think I might be wrong on that too.

For now I just need the information to create the INF file,

Thanks a lot for helping me,
Kobbe