alt Hacker NewsWhy do you use haver-sine over geodesic or reprojection?
I’ve been doing the reprojection thing, projecting coordinates to a “local” CRS, for previous projects mainly because that’s what geopandas recommend and is built around, but I am reaching a stage where I’d like to calculate distance for objects all over the globe, and I’m genuinely interested to learn what’s a good choice here.
Replies
colkassad • 05/04/2025
Look into Vincenty [1] or Karney (for a more robust solution) [2]. Vincenty should be good enough for most use cases.
wenc • 05/04/2025
Reprojection is accurate locally but inaccurate at scale.
Geodesics are the most accurate (Vincenty etc) but are computationally heavy.
Haversine is a nice middle ground.
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Just an app dev, not a geospatial expert, but reprojection always seemed like something a library should handle under the hood unless one has specific needs. I'm used to the ergonomics / moron-proofing of something like Postgis' `ST_Distance(geography point1, geography point2)` and it gives you the the right answer in meters. You can easily switch to spherical or Cartesian distances if you need distance calculations to go faster. `ST_Area(geography geog)` and it gives you the size of your shape in square meters wherever on the planet.