Alcatraz - Telegraph Hill Maps

Here are high resolution relief maps of Alcatraz and Telegraph Hill. At one third arc-second resolution streets begin to appear in the stl images. However the vertical differences that show the streets are too small to appear in the printed map.

The Alcatraz map combines high and low tide versions; the tidal range at Alcatraz island is about 8 feet. The data comes from the USGS National Map.

http://viewer.nationalmap.gov/viewer/

Elevation data for the United States is available in two resolutions and in several formats. It is supplied as 1 degree square "tiles". The one third arc-second tile containing San Francisco was downloaded in GridFloat format. More information is available at:

http://nationalmap.gov/elevation.html

Fortran source code that outputs openSCAD code is included. When the openSCAD code is executed a relief map containing Telegraph Hill is produced.