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General Category => Map Making Support => Topic started by: NeuroDoc on October 04, 2008, 08:54:04 PM

Title: ArcGrid or GeoTiff - which is better?
Post by: NeuroDoc on October 04, 2008, 08:54:04 PM
When processing elevation data in Global Mapper, is one filetype better than the other? Is processing ArcGrid faster than GeoTiff? Does using one require less memory to process? Does one produce smaller files?

Thanks again.
Title: Re: ArcGrid or GeoTiff - which is better?
Post by: -Oz- on October 04, 2008, 10:35:42 PM
I don't really know but they should be about the same.  I use a different system than is in the tutorial so I have to use GeoTiff.

Another thing to take into account is that geotiff downloads are one large file whereas arcgrid is 4 files for the same coverage.  This means it takes more time to download but global mapper probably doesn't have to open it all at the same time so it may take a little less memory since it can free it before continuing to the next segment (assumption).
Title: Re: ArcGrid or GeoTiff - which is better?
Post by: NeuroDoc on October 05, 2008, 05:37:10 PM
Quote from: -Oz- on October 04, 2008, 10:35:42 PM
I don't really know but they should be about the same.  I use a different system than is in the tutorial so I have to use GeoTiff.

I'd love to know your system. I just finished compiling my topo map of Washington and it looks awful. It appears that none of the POI's were installed, it doesn't show oceans (the whole puget sound is missing), the elevation contours are extremely jagged, national parks aren't colored or labeled (but national forests are), no mountain peaks are labelled (probably related to the POI's missing). I'm sure I did something wrong somewhere, or have a setting wrong in global mapper.

Back to the beginning to try again.
Title: Re: ArcGrid or GeoTiff - which is better?
Post by: -Oz- on October 05, 2008, 07:36:57 PM
My program will only work with geotiff?  I'd be willing to send you a beta version but you need the geotiff ones.

Did you check the contours by zooming in to about 800ft?  Beyond that they may start to get jagged and at really zoomed out elevations they are jagged.

Weird the POIs weren't installed.  Did global mapper have any errors (getting plagued by errors with Idaho's elevation data)?