Increase readahead on virtio block devices

[chef.git] / cookbooks / imagery / recipes / gb_os_sv.rb

diff --git a/cookbooks/imagery/recipes/gb_os_sv.rb b/cookbooks/imagery/recipes/gb_os_sv.rb
index c6fa2b8c913b40eb7e17b20b6f07f3699ef38ecc..e8781cbe237f6eb330d34a59c6b8c9a65bcb4f96 100644 (file)
--- a/cookbooks/imagery/recipes/gb_os_sv.rb
+++ b/cookbooks/imagery/recipes/gb_os_sv.rb
@@ -1,4 +1,3 @@
-# coding: utf-8

 #
 # Cookbook Name:: imagery
 # Recipe:: gb_os_sv
 #
 # Cookbook Name:: imagery
 # Recipe:: gb_os_sv


@@ -9,7 +8,7 @@
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #

-#     http://www.apache.org/licenses/LICENSE-2.0
+#     https://www.apache.org/licenses/LICENSE-2.0

 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,


@@ -43,12 +42,13 @@ end
 
 imagery_site "os.openstreetmap.org" do
   title "OpenStreetMap - Ordnance Survey OpenData - Street View"
 
 imagery_site "os.openstreetmap.org" do
   title "OpenStreetMap - Ordnance Survey OpenData - Street View"

-  aliases ["os.openstreetmap.org.uk"]
+  aliases ["os.osm.org", "os.openstreetmap.org.uk"]

   bbox [[49.85, -10.5], [58.75, 1.9]]
 end
 
 imagery_layer "gb_os_sv_2010_04" do
   site "os.openstreetmap.org"
   bbox [[49.85, -10.5], [58.75, 1.9]]
 end
 
 imagery_layer "gb_os_sv_2010_04" do
   site "os.openstreetmap.org"

+  title "April 2010"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2010-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010" # FIXME: Correct Copyright?
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2010-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010" # FIXME: Correct Copyright?


@@ -59,6 +59,7 @@ end
 
 imagery_layer "gb_os_sv_2010_11" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2010_11" do
   site "os.openstreetmap.org"

+  title "November 2010"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2010-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010" # FIXME: Correct Copyright?
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2010-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010" # FIXME: Correct Copyright?


@@ -69,6 +70,7 @@ end
 
 imagery_layer "gb_os_sv_2011_05" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2011_05" do
   site "os.openstreetmap.org"

+  title "May 2011"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2011-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011" # FIXME: Correct Copyright?
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2011-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011" # FIXME: Correct Copyright?


@@ -79,6 +81,7 @@ end
 
 imagery_layer "gb_os_sv_2011_11" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2011_11" do
   site "os.openstreetmap.org"

+  title "November 2011"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2011-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011" # FIXME: Correct Copyright?
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2011-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011" # FIXME: Correct Copyright?


@@ -89,6 +92,7 @@ end
 
 imagery_layer "gb_os_sv_2012_05" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2012_05" do
   site "os.openstreetmap.org"

+  title "May 2012"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2012-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2012-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"


@@ -99,6 +103,7 @@ end
 
 imagery_layer "gb_os_sv_2012_11" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2012_11" do
   site "os.openstreetmap.org"

+  title "November 2012"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2012-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2012-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"


@@ -109,6 +114,7 @@ end
 
 imagery_layer "gb_os_sv_2013_05" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2013_05" do
   site "os.openstreetmap.org"

+  title "May 2013"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2013-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2013-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"


@@ -119,6 +125,7 @@ end
 
 imagery_layer "gb_os_sv_2013_11" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2013_11" do
   site "os.openstreetmap.org"

+  title "November 2013"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2013-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2013-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"


@@ -129,6 +136,7 @@ end
 
 imagery_layer "gb_os_sv_2014_04" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2014_04" do
   site "os.openstreetmap.org"

+  title "April 2014"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2014-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2014-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"


@@ -139,6 +147,7 @@ end
 
 imagery_layer "gb_os_sv_2014_10" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2014_10" do
   site "os.openstreetmap.org"

+  title "October 2014"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2014-10-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2014-10-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"


@@ -149,6 +158,7 @@ end
 
 imagery_layer "gb_os_sv_2015_05" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2015_05" do
   site "os.openstreetmap.org"

+  title "May 2015"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2015-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2015-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"


@@ -159,7 +169,7 @@ end
 
 imagery_layer "gb_os_sv_2015_11" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2015_11" do
   site "os.openstreetmap.org"

-  root_layer true
+  title "November 2015"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2015-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2015-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"


@@ -170,7 +180,8 @@ end
 
 imagery_layer "gb_os_sv_2016_04" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_2016_04" do
   site "os.openstreetmap.org"

-  root_layer true
+  title "April 2016"
+  default_layer true

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2016-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-2016-04-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"


@@ -179,9 +190,11 @@ imagery_layer "gb_os_sv_2016_04" do
   url_aliases ["/sv-2016-04", "/sv"] # Add "/sv" to current edition for backward compatibility
 end
 
   url_aliases ["/sv-2016-04", "/sv"] # Add "/sv" to current edition for backward compatibility
 end
 

-# Diff layers
+# ======= Diff layers =======
+

 imagery_layer "gb_os_sv_diff_2010_04_2010_11" do
   site "os.openstreetmap.org"
 imagery_layer "gb_os_sv_diff_2010_04_2010_11" do
   site "os.openstreetmap.org"

+  title "Changes April 2010 to November 2010"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2010-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2010-11-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2010"


@@ -192,6 +205,7 @@ end
 
 imagery_layer "gb_os_sv_diff_2010_04_2011_05" do
   site "os.openstreetmap.org"
 
 imagery_layer "gb_os_sv_diff_2010_04_2011_05" do
   site "os.openstreetmap.org"

+  title "Changes April 2010 to May 2011"

   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2011-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
   projection "EPSG:27700"
   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2011-05-combined.vrt"
   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"


@@ -200,764 +214,838 @@ imagery_layer "gb_os_sv_diff_2010_04_2011_05" do
   overlay true
 end
 
   overlay true
 end
 

-#
-# imagery_layer "gb_os_sv_diff_2010_04_2011_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2011-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2011-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_04_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-04-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2011_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2011-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2011_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2011-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2010_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2010-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2011_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2011-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2011-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2012_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2012-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2011_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2011-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2012_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2012-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2012-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2013_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2013-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2012_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2012-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2013_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2013-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2013-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2014_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2014-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2013_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2013-11-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2014_10" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2014-10-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2014-10"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_04_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-04-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_10_2015_05" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-05-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-10-2015-05"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_10_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-10-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2014_10_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2014-10-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2015_05_2015_11" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2015-11-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2015-05-2015-11"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2015_05_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2015-05-2016-04"]
-#   overlay true
-# end
-#
-# imagery_layer "gb_os_sv_diff_2015_11_2016_04" do
-#   site "os.openstreetmap.org"
-#   projection "EPSG:27700"
-#   source "/data/imagery/gb/os-sv/ossv-diff-2015-11-2016-04-combined.vrt"
-#   copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
-#   extension "os_sv_diff_png"
-#   url_aliases ["/sv-diff-2015-11-2016-04"]
-#   overlay true
-# end
-#
+imagery_layer "gb_os_sv_diff_2010_04_2011_11" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2011-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2011-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_04_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes April 2010 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-04-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-04-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2011_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2011-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2011_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2011-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2011-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2010_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2010 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2010-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2010-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2011_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2011"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2011-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2011-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2011 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2012_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to May 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2012-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2011"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2011_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2011 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2011-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2011-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2012_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to November 2012"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2012-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2012"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2012-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2012 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2013_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to May 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2013-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2012_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2012 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2012-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2012-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2013_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to November 2013"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2013-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2013"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2013-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2013 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2014_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to April 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2014-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2013_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2013 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2013-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2013-11-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2014_10" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to October 2014"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2014-10-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2014"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2014-10"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_04_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes April 2014 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-04-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-04-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_10_2015_05" do
+  site "os.openstreetmap.org"
+  title "Changes October 2014 to May 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-05-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-10-2015-05"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_10_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes October 2014 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-10-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2014_10_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes October 2014 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2014-10-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2014-10-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2015_05_2015_11" do
+  site "os.openstreetmap.org"
+  title "Changes May 2015 to November 2015"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2015-11-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2015"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2015-05-2015-11"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2015_05_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes May 2015 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2015-05-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2015-05-2016-04"]
+  overlay true
+end
+
+imagery_layer "gb_os_sv_diff_2015_11_2016_04" do
+  site "os.openstreetmap.org"
+  title "Changes November 2015 to April 2016"
+  projection "EPSG:27700"
+  source "/data/imagery/gb/os-sv/ossv-diff-2015-11-2016-04-combined.vrt"
+  copyright "Contains Ordnance Survey data © Crown copyright and database right 2016"
+  extension "os_sv_diff_png"
+  url_aliases ["/sv-diff-2015-11-2016-04"]
+  overlay true
+end