Hi Burkhard, I'll tell you I have never worked with a .nc type binary file and resample before. The "SourceDir="." have you tried making that a path to your folder like "C:\batyhmetry? Have you tried running the bathymetry through resample as "Layer=Elevation?" I'll see if I can make a .nc type file in the meantime.

Did Elevation work? What tools are you using to create your elevation data?

Thanks for the link to geomapapp, i'll try and look at some of their data. When you say "resample doesn't like their geotiffs" what do you mean, do you get an error or any message? My first guess is they could be tiled geotiff,or possibly not in the correct coordinate system, but resample will tell you in those cases.

I think the bathymetry tutorial is a great idea!

Hi Burkhard.

I used gdal_translate to make a geotiff that woked for me.

gdal_translate -a_srs EPSG:4326 -of GTiff gebco_08_-85_17_-72_24.nc gebco_08_-85_17_-72_24.tif

-a_srs EPSG:4326 identifies the source datum and projection as WGS84 geodetic

-of GTiff sets the output as GeoTiff

gebco_08_-85_17_-72_24.nc is the source file

gebco_08_-85_17_-72_24.tif is my GeoTiff

The INF:

[Destination]
DestDir ="."
DestBaseFileName = "CubanWaters"
LOD=7

[Source]
Type = GeoTiff
SourceDir ="."
SourceFile = "gebco_08_-85_17_-72_24.tif"
Layer=Bathymetry

This produces a bgl that looks right. gdal_translate is available in FWTools or part of the OSGeo4W package ( which I prefer ).

Dick

Again,

I found this to apparently work:

[Destination]
	LOD = 7
	DestDir = "."
	DestBaseFileName = "NC_01"
	UseSourceDimensions = 1
	FractionBits = 0
	BaseValue = 0

[Source]
	Layer = Bathymetry
	Type = ElevS16MSB
	SourceDir = "."
	SourceFile = "gebco_08_-85_17_-72_24.nc"
	Lat = 24.4708333
	Lon = -85.4708333
	NumOfCellsPerLine = 1574
	NumOfLines = 790
	CellXdimensionDeg = 0.0083333333333333
	CellYdimensionDeg = 0.0083333333333333
	FractionBits = 0
	BaseValue = 0
	SkipBytes = 612

SkipBytes gets rid if the embedded header code. Your SkipBytes may need to be different??? Type = ElevS16MSB MSB formatting of the data.

Dick

Not yet really successfull. Using the full GEBPCO_08.NC file, which is documented.. and the following inf file:
==================================
[Destination]
DestDir ="E:\"
DestBaseFileName = "0602_bath"
LOD=7
FractionBits = 0
BaseValue = 0
NorthLat=45.0
SouthLat=22.5
WestLon=0.0
EastLon=30.0

[Source]
Type = ElevS16MSB
SourceDir ="."
SourceFile = "gebco_08.nc"
Layer=Bathymetry
Lon=-179.9958333333333
Lat=89.99583333333
CellXdimensionDeg = 0.0083333333333333
CellYdimensionDeg = 0.0083333333333333
NumOfCellsPerLine = 43200
NumOfLines = 21600
FractionBits = 0
BaseValue = 0
SkipBytes = 612
==================================

I get a 29MB bgl file. No matter where I place it, I only can dive down to 18 feet where it should be thousand meters, with very tiny changes when travelling a longer distance. Will experiment more...

Also though of that, so I just remove the default files by renaming them to .passive and made a world wide LOD=6 files, but still the same effect, 16-20 feet water debth.
Without my files, it is the same, so it looks it is not possible for some reason to dive outside the supplied US region.

The world file, according to the SDK manual, is ETOPO_Marianna.bgl, which contains a high resolution in the Marianna trench and a low one elsewhere.

The simple
==================================
[Destination]
DestDir ="."
DestBaseFileName = "0602_bath"
LOD=6
UseSourceDimensions = 1
FractionBits = 0
BaseValue = 0

[Source]
Type = ElevS16MSB
SourceDir ="."
SourceFile = "gebco_08.nc"
Layer=Bathymetry
Lon=-179.9958333333333
Lat=89.99583333333
CellXdimensionDeg = 0.0083333333333333
CellYdimensionDeg = 0.0083333333333333
NumOfCellsPerLine = 43200
NumOfLines = 21600
FractionBits = 0
BaseValue = 0
SkipBytes = 612
==================================
generates a 700MB file, all output looks well, when I look at it with TMFviewer it looks resonable, just I cannot dive yet. Hope to have a bit of time for it again next weekend...