Pseudocolor : Bathymetry

Bathymetry and relief plot from the Carolinas Coastal Ocean Observing and Prediction System

The Carolinas Coastal Ocean Observing and Prediction System sponsors research concerning ocean storms and climate affecting the Carolinas shore in North America. This plot illustrates a display of both land relief and bathymetry using their bathymetry data set. The plot is good way to learn some of the features of the ODC's color control system.

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Step-By-Step

Search / Dataset List retrieve Carolinas Coastal Ocean Observing and Prediction System / Storm Surge directory open "bathy" directory double-click bathys.nc file to get DDS select Grid and bathymetry variables from DDS output to plotter discussion: In this intermediate plot we can see a couple of things. First of all the missing values found automatically by the ODC (1.0 4.0 5.0 15.0) are incorrect. This is because developed areas near the coast are paved over and have identical elevations. This leads to spikes in the datasets that the ODC identifies as possible missing values. We can turn this mistake to our advantage however because it neatly shows where the developed areas are which will be a good addition to our plot Another thing about this plot is that the default colors spread right across the border between ocean and land. It would be much better if we could set distinctive colors for the land and ocean. We can generate just such colors by using the multi-hue color generator. If you are unfamiliar with the color generator you may want to read the help topic on this feature to get an idea of what it can do. in the plotter go to the colors tab Plot Specification : change "Plots generate their own colors" to "Plot uses: Default" Color Generator : create a 2-color multi-hue [two new ranges will appear] select the default range (that goes from -4197.4 to 275) and delete it Now we want to make the break between the hues at the 0 elevation (the coast). select range 1 (-4197 : -1961.2) change range 1's DataTo range from -1961.2 to 0 select range 2 (-1961.2 : 275.0) change range 2's DataTo range from -1961.2 to 0 modify the colors of range 1 to go from cyan to magenta continuously intensify the red highlights by increasing the brightness on the dark end of range 2 modify text annotations plot it

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OPeNDAP Data Connector Plot Gallery · Revised 25 January 2004 ·