The following bug has been logged on the website:
Bug reference: 6556
Logged by: Kasper Sandberg
Email address: kontakt(at)sandberg-consult(dot)dk
PostgreSQL version: 9.1.3
Operating system: -
Description:
looking at http://www.postgresql.org/docs/9.1/static/earthdistance.html
it looks very scarce and missing, and conflicting, some things operate based
on miles, others meters. it also doesnt specify the units used for
earth_distance() which seems to be meters.