Creating a GeoTiff for use in CE

This might be a bit too wonky to pull off, but we use CE while doing rockfish surveys for the Alaska Department of Fish and Game and we have some high resolution bathymetry rasters in ArcMap that I would love to bring into CE. CE accepts GeoTiff files and I have read the image settings that are compatible with CE in the help menu, but I still cannot get any GeoTiffs to load. I have access to ArcMap, QGis and other software titles, but I’m no GIS expert.

Anyone here have a means of creating custom raster map layers for use in CE?

Cheers,
P

These are the parameters offered in the help menu:

Using Topographic Maps and GeoTIFF Files

  • The GeoTIFF image file format is very complex and has a lot of options, some of which are not compatible with Coastal Explorer. Here are the options that are supported:
  • Color Formats: monochromatic, grayscale, palletized, or RGB
  • Color Resolution: 1, 4, 8, 24, or 32 bits per pixel
  • Compression: PackBits or JPEG
  • Image Format: Tiled or Non-tiled
  • Model: Geographic or Projected
  • Geographic Coordinate Systems: WGS-84, WGS-72, NAD-27, or NAD-83
  • Projections: Transverse Mercator, Transverse Mercator (Alaska), Mercator
  • Map Systems: UTM North or UTM South

I ditched trying to do this in ArcMap and used QGIS instead. I got it to work loading the tif raster and then exporting via the Save As… menu, saved it as a GTiff file, used WGS84 as the coordinate reference (EPSG:4326) and de-selected any other bells and whistles. The file is large (550 MB) and bogs CE down, but it worked. Nice.

1 Like

P,

And you aren’t an expert? You underestimate yourself. I’ve had zero success in that area with CE or even using the USGS site to download and use topo maps other than as PDF documents which don’t display well. The lack of small scale maps in Alaska is no help. I wish I had better bathymetry data of southeast for fishing, but it is lacking unless you capture it yourself. Navionics pretends to display detailed data, but the actual depths and contours are way off in most places.

Tom

It’s a total PITA but you can download GIS ‘bag’ files (Bathymetric Attributed Grid) for many parts of Alaska (not much around Kodiak so far) and make them into GeoTiffs for CE, which is what I have done. I only did the last export step to .tif in QGIS which is free and open source, but I did some work ahead of time in ArcMap which is definitely not free or open source. It was a tedious, annoying, trial-and-error process that I would have a hard time replicating and will probably forget entirely in a week.

You can get the bag files from NOAA here. Bathymetric Data Viewer

Here is one of our rockfish survey grids near Nuka Island with the bathymetry layer in CE: