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