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2<!--#set var="link" value="/FAQ.html" -->
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4<!--#include virtual="inc/header.shtml" -->
5
6<ul>
7<li><a href="#whatIsIt">What is it?</a></li>
8<li><a href="#licence">What licence does the data have?</a></li>
9<li><a href="#junkMail">Will I get more junk mail if I enter my postcode?</a></li>
10<li><a href="#whatMaps">What maps are you using?</a></li>
11<li><a href="#doAnything">So can I do what I like with your scans/tiles?</a></li>
12<li><a href="#download">Okay; I can use the tiles for some things; can I download the complete set?</a></li>
13<li><a href="#worldFiles">It'd be really great if I could get a world file / .jpw / etc</a></li>
14<li><a href="#orthorectifying">Isn't orthowotsiting an old map hard?</a></li>
15<li><a href="#openstreetmap">Why don't you use maps created from OpenStreetMap data?</a></li>
16<li><a href="#freethepostcode">Will this data be imported back into Free the Postcode?</a></li>
17<li><a href="#accuracy">If you are using scans of old maps, how accurate will the locations be?</a></li>
18<li><a href="#houseMissing">My house isn't on a 1950s map</a></li>
19<li><a href="#pickDecade">How do I view maps from different decades?</a></li>
20<li><a href="#gps">I know exactly where I am, and what my postcode is</a></li>
21<li><a href="#islands">I can't seem to find a certain island on your overview map</a></li>
22<li><a href="#howToUse">So, how do I use it?</a></li>
23<li><a href="#code">Is the code behind the site available?</a></li>
24<li><a href="#codepoint">Psst, I have a copy of the codepoint database. Wanna look?</a></li>
25<li><a href="#otherdata">Here's another source of free postcodes</a></li>
26<li><a href="#codepointBusiness">Won't you drive codepoint out of business?</a></li>
27<li><a href="#tileJoins">The map doesn't join up.</a></li>
28<li><a href="#helpOrthorectifying">The wonkiness is so annoying it drives me mad, and I have experience of orthrectifying maps. Please let me straighten your maps.</a></li>
29<li><a href="#gdal">Why didn't you use proj/gdal?</a></li>
30<li><a href="#scotland">Why did it take you so long to have good mapping data of Scotland?</a></li>
31<li><a href="#northernIreland">Why don't you have mapping data of Northern Ireland?</a></li>
32<li><a href="#who">Who did the work?</a></li>
33</ul>
34
35<hr />
36
37
38<a name="whatIsIt"></a>
39<h3>What is it?</h3>
40
41<p>There are a lot of applications on websites for being able to tell where
42people are from their postcode. For example "Where is my nearest
43B&amp;Q?". Unfortunately this data is expensive to licence (a few
44thousand pounds/year for a website). <a
45href="http://www.freethepostcode.org">Free the postcode</a> are doing a
46good job, but it is hard to contribute to their database as you
47need a GPS, so they have few postcodes.</p>
48
49<p>Our goal is to collect postcode data by getting users to locate
50themselves on a map of the country. They need only give the first part
51of their postcode, and if we can collect locations for all of these
52parts then we can create a database that is good enough for many
53applications. We are also accepting complete postcodes and 'partial'
54postcodes including the number portion of the second half of the postcode,
55in order to improve our accuracy.
56</p>
57
58
59<a name="licence"></a>
60<h3>What licence does the data have?</h3>
61
62<p>The data will be will be in the public domain; consequently, users
63submitting data agree to their submission being in the public domain
64when they enter their postcode.</p>
65
66
67<a name="junkMail"></a>
68<h3>Will I get more junk mail if I enter my postcode?</h3>
69
70<p>
71No, we are just interested in where the postcode is. We don't collect
72your name or house number. Please see our <a href="/privacy.html">privacy policy</a>.</p>
73
74
75<a name="whatMaps"></a>
76<h3>What maps are you using?</h3>
77
78<p>We have scans of out of copyright OS maps of England, Scotland and Wales.
79You can <a href="scotlandAndNI.html">register interest in future projects
80involving Northern Ireland</a>.</p>
81
82
83<a name="doAnything"></a>
84<h3>So can I do what I like with your scans/tiles?</h3>
85
86<p>
87No. The scans and tiles have been placed under a
88<a href="tileLicence.html">licence</a>; they are not in the public
89domain.
90</p>
91
92
93<a name="download"></a>
94<h3>Okay; I can use the tiles for some things; can I download the complete set?</h3>
95
96<p>
97We have all the tiles available in a couple of different naming schemes, but
98not all of them are on machines with suitable internet connections for
99downloading from.</p>
100
101<p>If you <a href="reportBug.html">drop us an email</a> letting us know which
102areas you are interested in (ideally either sheet numbers, or the whole lot),
103and confirm that your use falls within <a href="#licence">the tile
104licence</a>, we can work out the best way to let you get the tiles. It may
105even be possible for us to post you a dvd of the tiles, but we'll normally
106request a donation to <a href="http://www.openstreetmap.org/">OpenStreetMap</a>
107in-leui of the postage.
108</p>
109
110<p>One thing we do ask is that if you want to use the tiles; please don't
111try and crawl our tileserver to obtain the entire set.
112<a href="reportBug.html">Let us know</a> what you're after, and we can
113probably sort something out!
114</p>
115
116
117<a name="worldFiles"></a>
118<h3>It'd be really great if I could get a world file / .jpw / etc
119 for the tiles I'm looking at, so I can feed it to gdal / mapserv / etc</h3>
120
121<p>It's very easy to turn a tile's URL into the location of any of its
122 corners. We have a script that will happily spit out .jpw world files for
123 any of our tiles, which various people make use of.</p> 
124
125<p><a href="reportBug.html">Let us know</a> if you're interested, and we
126 can either send you a bunch of world files, or the magic perl script.</p>
127
128<p>You may also be interested in the WMS server of the tiles run by
129 <a href="http://www.blacksworld.net/">Nick Black</a>. He gives the details
130 of it in <a href="http://www.blacksworld.net/blog/?p=83">this blog post.</a>
131</p>
132
133
134<a name="orthorectifying"></a>
135<h3>Isn't orthowotsiting an old map hard?</h3>
136
137<p>Luckily we're going to work in the OSGB coordinate system that
138matches up with the grid lines on the map; this means we don't have to
139distort the maps too much. We also are not overly fussy about the
140accuracy, so this step can be done quickly.</p>
141
142
143<a name="openstreetmap"></a>
144<h3>Why don't you use maps created from <a
145href="http://www.openstreetmap.org">OpenStreetMap</a> data?</h3>
146
147<p>Because they are licensed under Creative Commons Share-alike
148licences, so we wouldn't be able to make our data public domain.</p>
149
150<p>There are people who believe that locating a point on a map creates a
151derived work, and hence requires a licence. We don't want to be the first
152to prove them wrong in a court, as that will be pricy.</p>
153
154<p>Also, the OpenStreetMap maps are not yet complete enough to achieve our
155goal of country-wide coverage.</p>
156
157
158<a name="freethepostcode"></a>
159<h3>Will this data be imported back into Free the Postcode?</h3>
160
161<p>Probably not directly. We are looking at the best way of presenting
162data from both projects whilst not polluting the Free the Postcode database
163with our lower accuracy data. We are importing Free the Postcode data into
164our database for display, but not re-exporting it currently.</p>
165
166
167<a name="accuracy"></a>
168<h3>If you are using scans of old maps, how accurate will the locations
169be?</h3>
170
171<p>Some of the scans are out by a degree or two but they are fairly
172good. We hope to be able to get better than 100 metres accuracy out of it in
173the end. This is more than good enough to locate a region as large as
174the first half of a postcode, and hopefully as much as the 'partial'
175postcodes described in the answer to 'What is it?' above.</p>
176
177
178<a name="houseMissing"></a>
179<h3>My house isn't on a 1950s map</h3>
180
181<p>Find some local landmarks and guess where your house is. This is
182accurate enough for our purposes.</p>
183
184
185<a name="pickDecade"></a>
186<h3>How do I view maps from different decades?</h3>
187
188<p>For many areas, we have maps from a number of different years. By default,
189 we always show you the most recent map we have. That gives you the best
190 chance to locate postcodes, and allows us to produce the best list
191 of free postcodes that we can.</p>
192
193<p>However, we do understand that sometimes people would like to be able
194 to compare how things have changed. For that reason, we provide a second
195 interface to view our maps. With this one, we allow you to browse all
196 of our maps from each decade.</p>
197
198<p>You can browse by decade by <a href="/pickDecade.html">going here</a>.
199 (We currently have maps from the 1920s, 1930s, 1940s and 1950s).
200 Please note that we do not have maps for all areas for all decades, so
201 you may find that you can only view a given place at only one or two
202 dates.</p>
203
204<p>If you have maps for an area for a decade that we currently don't,
205 please do contact us.</p>
206
207
208<a name="gps"></a>
209<h3>I know exactly where I am, and what my postcode is</h3>
210
211<p>If you have a GPS, enter your data into <a
212href="http://www.freethepostcode.org">Free the Postcode</a> and make the
213world a better place.</p>
214
215
216<a name="islands"></a>
217<h3>I can't seem to find a certain island on your overview map</h3>
218<p>We've put together a list of <a href="islands.html">hard to find
219 islands</a>, so you might well be able to find it from there.</p>
220
221
222<a name="howToUse"></a>
223<h3>So, how do I use it?</h3>
224
225<p>Find your location on our map, click where your postcode is, enter
226the postcode, agreeing to release your data.</p>
227
228
229<a name="code"></a>
230<h3>Is the code behind the site available?</h3>
231<p>Yes, the code that powers the site is available in a public
232svn repository. You're welcome to check out the code from
233<a href="https://urchin.earth.li/svn/npemap/">https://urchin.earth.li/svn/npemap/</a></p>
234<p>The code is all under an open, MIT like license, see
235<a href="https://urchin.earth.li/svn/npemap/trunk/COPYING">here</a>
236for details.</p>
237
238
239<a name="codepoint"></a>
240<h3>Psst, I have a copy of the codepoint database. Wanna look?</h3>
241
242<p>No thanks, we want free data so we don't have to keep paying the nice
243codepoint people. </p>
244
245<a name="otherdata"></a>
246<h3>Here's another source of free postcodes</h3>
247
248<p>There are many unattributed postcodes sets on the web, but none others
249(apart from freethepostcode.org, which we are already working with) which
250are unambiguously free. In particular there is a <a href="http://www.jibble.org/ukpostcodes/">site</a> which lots of people have pointed at. Unfortunately
251there is no actual data there; the data was removed after the Post Office
252issued a take-down notice to this site. We're only interested in public
253domain database (or possibly databases with other unambiguously "free"
254licensing terms).
255</p>
256
257
258<a name="codepointBusiness"></a>
259<h3>Won't you drive codepoint out of business?</h3>
260
261<p>We don't think so. There are a lot of places where this level of
262accuracy just isn't enough. Those people will still have to pay until
263<a href="http://www.freethepostcode.org">Free the Postcode</a> improves
264its coverage.</p>
265
266
267<a name="tileJoins"></a>
268<h3>The map doesn't join up.</h3>
269
270<p>Yes, it isn't perfect. The OS didn't publish a single map of the whole
271country, so you have to scan then stick together data from several maps.
272We don't really know how to correct it perfectly. It would be really cool
273if someone could write software to detect the gridlines and automatically
274cut the images up on the lines and make them square.</p> 
275
276
277<a name="helpOrthorectifying"></a>
278<h3>The wonkiness is so annoying it drives me mad, and I have experience of orthrectifying maps. Please let me straighten your maps.</h3>
279
280<p>Cool. Contact us, that would be great.</p>
281
282
283<a name="gdal"></a>
284<h3>Why didn't you use proj/gdal?</h3>
285
286<p>Because we don't know how to work them. If you feel like improving how this
287works, let us know. Update: We do use proj for the <a href="/postcodeine/">postcode display</a>.</p>
288
289
290<a name="scotland"></a>
291<h3>Why did it take you so long to have coverage of Scotland?</h3>
292
293<p>While the Ordnance Survey did create the New Popular Edition maps of
294 Scotland at 1 inch to the mile, these were never published, so we can't
295 buy them to scan in. Scotland was included in the Ordnance Survey
296 7<sup>th</sup> Edition at 1 inch to the mile, but almost all of these
297 maps remain in copyright for another few years, so we can't put them
298 online yet</p>
299<p>The Ordnance Survey did release some updates to the Popular Edition
300 of Scotland in the 1940s, which had the National Grid over-printed on.
301 them. (The War Office also published similar versions). While the grid
302 isn't parallel with the main map, it is possible to work with (just a
303 little bit more work). It has taken us much longer to track these down
304 than it took us to get the England and Wales New Popular Edition maps.
305 This is why we have only recently been able to offer a high degree of
306 coverage for Scotland.</p>
307
308<p>We now think we have completed our coverage of Scotland. Most of the
309 maps used are from the 1940s, but there are small numbers of earlier maps
310 (mostly 1920s), and small numbers of 7<sup>th</sup> edition maps from the
311 1950s. To see the coverage we have, visit the
312 <a href="/tiles/allmaps.html">large overview map.</a></p>
313
314
315<a name="northernIreland"></a>
316<h3>Why don't you have mapping data of Northern Ireland?</h3>
317
318<p>For Northern Ireland, the situation is harder than for Scotland,
319 because the Ordnance Survey of Northern Ireland didn't produce an
320 equivalent to the New Popular Edition, instead it produced a number of
321 updates without altering the name of the edition. So, many of the maps
322 from the Popular Edition of Northern Ireland are still in Copyright, so
323 it's hard to know if a given old map is out of copyright just from the
324 name.</p>
325<p>Compounding this, it is much harder to track down second hand maps
326 of Northern Ireland, compared to the difficulty of getting English,
327 Welsh and Scottish maps of the period. We have also yet to come across
328 any institutional holdings of old Northern Irish maps where the
329 holder will allow scans to be made. All we have been able to get is
330 quarter inch to the mile maps, which don't fit into our tiling scheme,
331 and are too small for finding postcodes on.</p>
332
333<p>If you would like to be notified when we do get out of copyright 1 inch
334 to the mile maps of Northern Ireland, please
335 <a href="scotlandAndNI.html">register your interest</a>.</p>
336
337
338<a name="who"></a>
339<h3>Who did the work?</h3>
340
341<ul>
342<li>Richard Fairhurst acquired and scanned the maps of England and Wales,</li>
343<li>Nick Burch, Andrew Rowbottom and Mike Calder have aquired and scanned
344 many of the maps of Scotland,</li>
345<li>The <a href="http://steve8.dev.openstreetmap.org/os7.htm">OpenStreetMap
346 7th Edition Project</a> have aquired and scanned some of the 7th
347 Edition maps of Scotland,</li>
348<li>Dominic Hargreaves, David Sheldon and Nick Burch straightened and tiled
349 the maps,</li>
350<li>Matthew Westcott, <a href="http://www.earth.li/~dave/">David Sheldon</a>,
351 Dominic Hargreaves and Nick Burch worked on the user interface and backend
352 software.</li>
353<li><a href="http://www.torchbox.com">Torchbox</a> has supported the project
354 with some development time and design work.</li>
355</ul>
356
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