Difference between revisions of "Great Lakes Bathymetry"
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==CNC Carve== | ==CNC Carve== | ||
===Workflow=== | ===Workflow=== | ||
# Download shapefiles from [ | # Download shapefiles from [https://www.ngdc.noaa.gov/mgg/greatlakes/greatlakes.html NOAA]. Superior bathymetry contours with unclear provenance is available [https://databasin.org/datasets/88d305616c3e44cabbd465dde0d916c7 here], with login | ||
# Download and install [http://www.qgis.org/en/site/ QGIS] and [https://inkscape.org/en/download/ Inkscape]<ref>Stack Exchange answer [https://gis.stackexchange.com/questions/51980/how-to-convert-shapefile-to-vector-emf here]</ref> | # Download and install [http://www.qgis.org/en/site/ QGIS] and [https://inkscape.org/en/download/ Inkscape]<ref>Stack Exchange answer [https://gis.stackexchange.com/questions/51980/how-to-convert-shapefile-to-vector-emf here]</ref> | ||
# No need to extract files, open each in QGIS Desktop | # No need to extract files, open each in QGIS Desktop | ||
# Add OpenStreetMap information (not working at this time, | # Add OpenStreetMap information if desired (the native support is not working at this time<ref>"OpenStreetMap in QGIS." ''OpenStreetMap Wiki''. [http://wiki.openstreetmap.org/wiki/QGIS#OpenStreetMap_in_QGIS here].</ref>, but [https://plugins.qgis.org/plugins/OSMDownloader/ the plugin] does) | ||
# Right-click shapefile in left layers panel, select Properties | # Right-click shapefile in left layers panel, select Properties | ||
# Choose Filter, then create expression, e.g. "DEPTH" IN ('0', '1', '25', '50', '60')<ref>Geographic Information Systems Stack Exchange. "QGIS choose contour line labels." [https://gis.stackexchange.com/questions/121585/qgis-choose-contour-line-labels Here]</ref> | # Choose Filter, then create expression, e.g. "DEPTH" IN ('0', '1', '25', '50', '60')<ref>Geographic Information Systems Stack Exchange. "QGIS choose contour line labels." [https://gis.stackexchange.com/questions/121585/qgis-choose-contour-line-labels Here]</ref> | ||
{{note|It is helpful to use the Values box (make sure "Use unfiltered layer" is checked if changing an applied filter) to see the extent of the map}} | {{note|It is helpful to use the Values box (make sure "Use unfiltered layer" is checked if changing an applied filter) to see the extent of the map's values}} | ||
===Workflow Take 2=== | ===Workflow Take 2=== | ||
Revision as of 18:40, 9 June 2017
Ideas
Process of creating a 3D map of the area
Resources
- Downloadable Great Lakes bathymetric maps from NOAA
- The National Map combines many of the above resources
- The USGS Earth Explorer is easier to use than the above, but requires a login and download client
CNC Carve
Workflow
- Download shapefiles from NOAA. Superior bathymetry contours with unclear provenance is available here, with login
- Download and install QGIS and Inkscape[1]
- No need to extract files, open each in QGIS Desktop
- Add OpenStreetMap information if desired (the native support is not working at this time[2], but the plugin does)
- Right-click shapefile in left layers panel, select Properties
- Choose Filter, then create expression, e.g. "DEPTH" IN ('0', '1', '25', '50', '60')[3]
It is helpful to use the Values box (make sure "Use unfiltered layer" is checked if changing an applied filter) to see the extent of the map's values
Workflow Take 2
- Try this map with these instructions
- For OSM information, use Geofabrik.de and reformat if necessary as described here[4]
3D Print
- Download ArcGrid DEM from USGS National Map or Earth Explorer (3DEP, 1/3 arc-second DEM)
- Unzip file
- Open QGIS, add Vector, add layer file (.adf)
- Select extent (Raster -> Extraction -> Clipper)
- Save as GeoTIFF
- Add GeoTIFF to model
- Analyze to DEM (Raster -> Analysis -> DEM [Terrain Models])This step creates an apparently inaccurate model (top). Using 3DEM creates a more accurate representation, but the extent was smaller on the second.
- If necessary, merge the DEMs
- Solution to bathymetric (negative) altitude values[5]: using Raster Calculator, add bottom value to all height values
- Create STL (Raster -> DEMto3D)[6]
A note on resolution.
Other Sources
- Earth satellite imagery from USGS, esp. those over time
- ArcGIS contour map of the Great Lakes
- Live Access Servers hosted by NOAA/PMEL/TMAP provide information on air quality, ocean salinity, temperature, etc.
- LIDAR resources in case we want to machine it. I want to machine it.
- BBBike.org pulls from OSM, but extent is much too small.
- Using plywood (though very heavy) with the proper scale would approximate the contour lines of a topo map...
- Mosaicing and clipping rasters
- OceansMap, a well-aggregated set of realtime data about major bodies of water around the world, including the Great Lakes region
- Historical maps from the Army Corps of Engineers
- Portal for Great Lakes Observing System information from the Integrated Ocean Observing system
References
- ↑ Stack Exchange answer here
- ↑ "OpenStreetMap in QGIS." OpenStreetMap Wiki. here.
- ↑ Geographic Information Systems Stack Exchange. "QGIS choose contour line labels." Here
- ↑ Geographic Information Systems Stack Exchange. "Load .osm.pbf file in Qgis." here.
- ↑ Geographic Information Systems Stack Exchange. "Mars DTM has all negative elevations in QGIS. Can't build STL file for 3D print." here.
- ↑ Modified from Laguna Tools. "Max CNC Tutorial 3D Landscape." YouTube. here.