opengeospatial / geoedge-plugfest

Repository for Geospatial to the Edge Interoperability Plugfest
http://www.github.com/opengeospatial/geoedge-plugfest
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Issue queries raster question - scale #94

Open bermud opened 6 years ago

bermud commented 6 years ago

The client does not have a scale selector. The user can set the zoom level for the reader (zoom level 1 – 15). The user can also set the extents for any given query. Unlike plugfest 1, there was no extent information provided. So it is somewhat arbitrary what level of detail to show for 1:500000 and 1:20000.

Note that 1:25k is typically about 1km = 4cm. So the actual scale of this image depends on the size of the user interface frame and the monitor it is displayed on. The vertical distance was about 10 km (0.1 degrees) so you would need a monitor about 40cm tall to display this image in true 1:25000. So for these tests, I zoomed so that the display shows slightly more than 0.1 degrees as the vertical distance for the 1:20000 views. By the formula above, 1:500k should be 20km = 4cm, which by the above approach would yield a vertical distance of about 200 km or 1.8 degrees. In general, 1:500K is used for country or state level zoom, so I used that to display the full extent of Puerto Rico.