Article Title: After specifying a Map Projection under Display > Options, I get weird line plots
Article Name: RIVTOOLS5
OS Platforms: MACINTOSH; UNIX; WINDOWS
Last Updated: 11/02/2000

TOPIC:

When using a DEM with fixed-angle pixel geometry, RiverTools allows you to change the projection that all plots are drawn in under Display > Options. The user can select from any of a number of projections, plus specify whether or not to draw grid lines, coastlines, rivers, etc. on RiverTools plots. After changing the projection and selecting some of the additional options you may have noticed that some of your displays end up being weird line plots like these:

CONTOUR PLOT:



DENSITY PLOT:

DISCUSSION:

The cause of this problem is that you have erroneous bounding box info in the .rti file associated with this DEM. The most common mistakes are forgetting to include the negative sign ("-") in front of longitudes in the western hemisphere and latitudes in the southern hemisphere. For instance... the USGS 1-Deg. DEM for Denver East has a southeast corner at 39N Lat and -104W Lon... so its Bounding Box Info should be:

North edge value: 40
South edge value: 39
West edge value: -105
East edge value: -104


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