39 lines
1.2 KiB
Markdown
39 lines
1.2 KiB
Markdown
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from the US Census Bureau:
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https://www.census.gov/geographies/mapping-files/time-series/geo/cartographic-boundary.html
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more description here:
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https://www.census.gov/programs-surveys/geography/technical-documentation/naming-convention/cartographic-boundary-file.html
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Including the following:
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> # File Naming Convention
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> ## 2013 to Present Files
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>
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> The cartographic boundary files are named cb_yyyy_ss_<entity>_rr.zip where:
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>
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> * yyyy = 4 digit year
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> * ss = state FIPS code or 'us' for a national level file
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> * entity = the entity name
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> * rr = resolution level
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> * 500k = 1:500,000
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> * 5m = 1:5,000,000
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> * 20m = 1:20,000,000
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I prefer the KML options when available since OpenLayers doesn't [citation
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needed?] have built-in support for shapefiles (.shp)? That said, we also do
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transform KML to GeoJSON to be able to edit more easily (and it's sometimes good
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for a smaller file size).
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For more information, see e.g.:
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https://indicatrix.org/post/shapefiles-in-openlayers/
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Census Bureau data appears to be using a different (US-centric, possibly?)
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projection; this may require more work to be accurate going forward.
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https://gis.stackexchange.com/a/310949
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https://epsg.io/4269
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