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https://issues.apache.org/jira/browse/SOLR-2125?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12912827#action_12912827
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Yonik Seeley commented on SOLR-2125:
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bq. Distance using the Haversine function is extremely sensitive to what
spatial reference system the data was recorded in. WGS84 isn't particular great
with long distances.
I know nothing on this topic, but an error of 45% at 200 km? I'm pretty
certain that there is a bug not having to do with the accuracy of spatial
reference systems here.
> Spatial filter is not accurate
> ------------------------------
>
> Key: SOLR-2125
> URL: https://issues.apache.org/jira/browse/SOLR-2125
> Project: Solr
> Issue Type: Bug
> Components: Build
> Affects Versions: 1.5
> Reporter: Bill Bell
>
> The calculations of distance appears to be off.
> Note: "The radius of the sphere to be used when calculating distances on a
> sphere (i.e. haversine). Default is the Earth's mean radius in kilometers
> (see org.apache.solr.search.function.distance.Constants.EARTH_MEAN_RADIUS_KM)
> which is set to 3,958.761458084784856. Most applications will not need to set
> this."
> The radius of the earth in KM is 6371.009 km (≈3958.761 mi).
> Also filtering distance appears to be off - example data:
> 45.17614,-93.87341 to 44.9369054,-91.3929348 Approx 137 miles Google. 169
> miles = 220 kilometers
> http://....../solr/select?fl=*,score&start=0&rows=10&q={!sfilt%20fl=store_lat_lon}&qt=standard&pt=44.9369054,-91.3929348&d=280&sort=dist(2,store,vector(44.9369054,-91.3929348))
> asc
> Nothing shows. d=285 shows results. This is off by a lot.
> Bill
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