office1.rb

class Office < ActiveRecord::Base
end

# .. for example ..
o = Office.create(latitude: 32, longitude: -86)

office2.rb

class Office < ActiveRecord::Base
  searchable do
    latlon(:location) { Sunspot::Util::Coordinates.new(latitude, longitude) }
  end
end

office3.rb

# Offices within 100 kilometers of (32, -68)
Office.search { with(:location).in_radius(32, -68, 100) }

# Offices within a bounding box of 100 kilometers from (32, -68)
# A bounding box may include areas beyond 100 kilometers of
# (32, -68) so offices may be returned that are outside the
# desired region; however, the search may be more performant.
Office.search { with(:location).in_radius(32, -68, 100, bbox: true) }

office4.rb

Office.search { order_by_geodist(:location, 32, -68) }