<p><pre><code>    &gt; Lidar data is collected by low-, slow-flying aircraft with equipment
    &gt; that shoots millions of laser points to the ground. ... It is
    &gt; possible to strip buildings and vegetation from the images, so that
    &gt; only the ground is shown. In the Willamette River poster, the shades
    &gt; of white and blue show elevations. The purest white color is the
    &gt; baseline, (the zero point, at the lowest point near Independence on
    &gt; the upper part of the image). The darkest blue is 50 feet (or higher)
    &gt; than the baseline.
</code></pre>
Very cool, and really a beautiful image. Contour lines on a topographic map show the same data, but mapping the elevation to a color range and clipping out elevations outside the river&#x27;s effects really make this unlike anything I&#x27;ve seen before.<p>Edit: The original submission (see dang&#x27;s post) references a similar set of maps[0] for the Mississippi River, which are equally beautiful and even more impressive.<p>[0]: <a href="http:&#x2F;&#x2F;www.radicalcartography.net&#x2F;index.html?fisk" rel="nofollow">http:&#x2F;&#x2F;www.radicalcartography.net&#x2F;index.html?fisk</a>