Northeast Quadrant

“Northeast quadrant” appears to usually refer to a section of Washington, D.C. Here I mean the northeastern part of the contiguous U.S. (if one were to fold of map of it in half twice, the upper-right part, more or less).

This was generated using data from NASA’s Shuttle Radar Topography Mission. The actual tiles come from CGIAR-SCI. I used gdalwarp to reproject and combine the tiles:

gdalwarp \
  -r lanczos \
  -te -1270000 -661458 1270000 661458 \
  -t_srs "+proj=aea \
          +lat_1=29.5 \
          +lat_2=45.4 \
          +lat_0=44.0 \
          +lon_0=-83.0 \
          +x_0=0 +y_0=0" \
  -ts 960 0 \
  $(TILES) \
  relief.tiff

where $(TILES) is a list of the appropriate tif files, srtm_22_05.tif, srtm_21_05.tif and so on (19 in all). Then I used gdaldem to generate the hill shade:

gdaldem \
  hillshade \
  relief.tiff \
  hill-relief-shaded.tiff \
  -z 20 -az 90

Finally, I used Photoshop to remove a few “nodata” void areas in the Great Lakes and the ocean.

More about GDAL here.

Void-filled seamless SRTM data V1, 2004, International Centre for Tropical Agriculture (CIAT), available from the CGIAR-CSI SRTM 90m Database: http://srtm.csi.cgiar.org and http://www.ambiotek.com/topoview