source: trunk/ @ 732

Last change on this file since 732 was 732, checked in by Nick Burch, 12 years ago

Add a note about 7th edition OSM maps

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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" -->
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>
35<hr />
38<a name="whatIsIt"></a>
39<h3>What is it?</h3>
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="">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>
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.
59<a name="licence"></a>
60<h3>What licence does the data have?</h3>
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>
67<a name="junkMail"></a>
68<h3>Will I get more junk mail if I enter my postcode?</h3>
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>
75<a name="whatMaps"></a>
76<h3>What maps are you using?</h3>
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>
83<a name="doAnything"></a>
84<h3>So can I do what I like with your scans/tiles?</h3>
87No. The scans and tiles have been placed under a
88<a href="tileLicence.html">licence</a>; they are not in the public
93<a name="download"></a>
94<h3>Okay; I can use the tiles for some things; can I download the complete set?</h3>
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>
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="">OpenStreetMap</a>
107in-leui of the postage.
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!
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>
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> 
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>
128<p>You may also be interested in the WMS server of the tiles run by
129 <a href="">Nick Black</a>. He gives the details
130 of it in <a href="">this blog post.</a>
134<a name="orthorectifying"></a>
135<h3>Isn't orthowotsiting an old map hard?</h3>
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>
143<a name="openstreetmap"></a>
144<h3>Why don't you use maps created from <a
145href="">OpenStreetMap</a> data?</h3>
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>
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>
154<p>Also, the OpenStreetMap maps are not yet complete enough to achieve our
155goal of country-wide coverage.</p>
158<a name="freethepostcode"></a>
159<h3>Will this data be imported back into Free the Postcode?</h3>
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>
167<a name="accuracy"></a>
168<h3>If you are using scans of old maps, how accurate will the locations
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>
178<a name="houseMissing"></a>
179<h3>My house isn't on a 1950s map</h3>
181<p>Find some local landmarks and guess where your house is. This is
182accurate enough for our purposes.</p>
185<a name="pickDecade"></a>
186<h3>How do I view maps from different decades?</h3>
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>
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>
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>
204<p>If you have maps for an area for a decade that we currently don't,
205 please do contact us.</p>
208<a name="gps"></a>
209<h3>I know exactly where I am, and what my postcode is</h3>
211<p>If you have a GPS, enter your data into <a
212href="">Free the Postcode</a> and make the
213world a better place.</p>
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>
222<a name="howToUse"></a>
223<h3>So, how do I use it?</h3>
225<p>Find your location on our map, click where your postcode is, enter
226the postcode, agreeing to release your data.</p>
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=""></a></p>
234<p>The code is all under an open, MIT like license, see
235<a href="">here</a>
236for details.</p>
239<a name="codepoint"></a>
240<h3>Psst, I have a copy of the codepoint database. Wanna look?</h3>
242<p>No thanks, we want free data so we don't have to keep paying the nice
243codepoint people. </p>
245<a name="otherdata"></a>
246<h3>Here's another source of free postcodes</h3>
248<p>There are many unattributed postcodes sets on the web, but none others
249(apart from, which we are already working with) which
250are unambiguously free. In particular there is a <a href="">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).
258<a name="codepointBusiness"></a>
259<h3>Won't you drive codepoint out of business?</h3>
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="">Free the Postcode</a> improves
264its coverage.</p>
267<a name="tileJoins"></a>
268<h3>The map doesn't join up.</h3>
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> 
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>
280<p>Cool. Contact us, that would be great.</p>
283<a name="gdal"></a>
284<h3>Why didn't you use proj/gdal?</h3>
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>
290<a name="scotland"></a>
291<h3>Why did it take you so long to have coverage of Scotland?</h3>
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>
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>
315<a name="northernIreland"></a>
316<h3>Why don't you have mapping data of Northern Ireland?</h3>
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>
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>
338<a name="who"></a>
339<h3>Who did the work?</h3>
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="">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="">David Sheldon</a>,
351 Dominic Hargreaves and Nick Burch worked on the user interface and backend
352 software.</li>
353<li><a href="">Torchbox</a> has supported the project
354 with some development time and design work.</li>
357<!--#include virtual="inc/footer.shtml" -->
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