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General Category => Map Making Support => Topic started by: -Oz- on January 05, 2016, 06:50:45 PM

Title: USGS 1:24k Contours
Post by: -Oz- on January 05, 2016, 06:50:45 PM
So I am finally updating some of my maps and what browsing the National Map Viewer (have to update the tutorials too) I noticed they now have straight up 1:24k contours. They're at 1/3 arc sec which means that they "redo" the contour interval at those borders. This creates a few weird areas but it means that for my Arizona Topo instead of having a straight 30 or 40 ft contour interval in the flatter areas it'll be 5ft or 10ft.

Has anyone started using these contours instead of actually building from the DEM files? Seems like it would save a lot of computing time.  Also, the new downloader seems like it'd be nice but so far it isn't working...
Title: Re: USGS 1:24k Contours
Post by: -Oz- on January 09, 2016, 10:49:46 PM
So, since there aren't any replies I'm going to try these out on the updated Arizona map and see how they work.

This has also driven a huge update to the tutorial on contours: http://www.gpsfiledepot.com/tutorials/how-to-create-garmin-topo-maps---part-2---elevation-data/

Finally, With all the questions on QGIS I decided to try it out and see if it could be used to make the map making process much cheaper; so far so good. Had to create/update a whole new program to create the MP files from it but hey... that's the way it goes.
Title: Re: USGS 1:24k Contours
Post by: -Oz- on January 19, 2016, 09:06:10 PM
So I used the new 1:24K topos that the USGS provides on V3.0 of my Arizona Topo (http://www.gpsfiledepot.com/maps/view/1). If anyone wants to see how they worked out feel free to download and look.  This also used QGIS instead of Global Mapper (updating the tutorial).