source: trunk/npemap.org.uk/static/FAQ.html @ 528

Last change on this file since 528 was 528, checked in by Nick Burch, 13 years ago

Update scottish coverage in the faq, and new thumbnails

File size: 13.3 KB
Line 
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="#scotland">Why did it take you so long to have good mapping data of Scotland?</a></li>
29<li><a href="#northernIreland">Why don't you have mapping data of Northern Ireland?</a></li>
30<li><a href="#who">Who did the work?</a></li>
31</ul>
32
33<hr />
34
35
36<a name="whatIsIt"></a>
37<h3>What is it?</h3>
38
39<p>There are a lot of applications on websites for being able to tell where
40people are from their postcode. For example "Where is my nearest
41B&amp;Q?". Unfortunately this data is expensive to licence (a few
42thousand pounds/year for a website). <a
43href="http://www.freethepostcode.org">Free the postcode</a> are doing a
44good job, but it is hard to contribute to their database as you
45need a GPS, so they have few postcodes.</p>
46
47<p>Our goal is to collect postcode data by getting users to locate
48themselves on a map of the country. They need only give the first part
49of their postcode, and if we can collect locations for all of these
50parts then we can create a database that is good enough for many
51applications. We are also accepting complete postcodes and 'partial'
52postcodes including the number portion of the second half of the postcode,
53in order to improve our accuracy.
54</p>
55
56
57<a name="licence"></a>
58<h3>What licence does the data have?</h3>
59
60<p>The data will be will be in the public domain; consequently, users
61submitting data agree to their submission being in the public domain
62when they enter their postcode.</p>
63
64
65<a name="junkMail"></a>
66<h3>Will I get more junk mail if I enter my postcode?</h3>
67
68<p>
69No, we are just interested in where the postcode is. We don't collect
70your name or house number. Please see our <a href="/privacy.html">privacy policy</a>.</p>
71
72
73<a name="whatMaps"></a>
74<h3>What maps are you using?</h3>
75
76<p>We have scans of out of copyright OS maps of England, Scotland and Wales.
77You can <a href="scotlandAndNI.html">register interest in future projects
78involving Northern Ireland</a>.</p>
79
80
81<a name="doAnything"></a>
82<h3>So can I do what I like with your scans/tiles?</h3>
83
84<p>
85No. The scans and tiles have been placed under a
86<a href="tileLicence.html">licence</a>; they are not in the public
87domain.
88</p>
89
90
91<a name="download"></a>
92<h3>Okay; I can use the tiles for some things; can I download the complete set?</h3>
93
94<p>
95We have all the tiles available in a couple of different naming schemes, but
96not all of them are on machines with suitable internet connections for
97downloading from.</p>
98
99<p>If you <a href="reportBug.html">drop us an email</a> letting us know which
100areas you are interested in (ideally either sheet numbers, or the whole lot),
101and confirm that your use falls within <a href="#licence">the tile
102licence</a>, we can work out the best way to let you get the tiles. It may
103even be possible for us to post you a dvd of the tiles, but we'll normally
104request a donation to <a href="http://www.openstreetmap.org/">OpenStreetMap</a>
105in-leui of the postage.
106</p>
107
108<p>One thing we do ask is that if you want to use the tiles; please don't
109try and crawl our tileserver to obtain the entire set.
110<a href="reportBug.html">Let us know</a> what you're after, and we can
111probably sort something out!
112</p>
113
114
115<a name="worldFiles"></a>
116<h3>It'd be really great if I could get a world file / .jpw / etc
117 for the tiles I'm looking at, so I can feed it to gdal / mapserv / etc</h3>
118
119<p>It's very easy to turn a tile's URL into the location of any of its
120 corners. We have a script that will happily spit out .jpw world files for
121 any of our tiles, which various people make use of.</p> 
122
123<p><a href="reportBug.html">Let us know</a> if you're interested, and we
124 can either send you a bunch of world files, or the magic perl script.</p>
125
126<p>You may also be interested in the WMS server of the tiles run by
127 <a href="http://www.blacksworld.net/">Nick Black</a>. He gives the details
128 of it in <a href="http://www.blacksworld.net/blog/?p=83">this blog post.</a>
129</p>
130
131
132<a name="orthorectifying"></a>
133<h3>Isn't orthowotsiting an old map hard?</h3>
134
135<p>Luckily we're going to work in the OSGB coordinate system that
136matches up with the grid lines on the map; this means we don't have to
137distort the maps too much. We also are not overly fussy about the
138accuracy, so this step can be done quickly.</p>
139
140
141<a name="openstreetmap"></a>
142<h3>Why don't you use maps created from <a
143href="http://www.openstreetmap.org">OpenStreetMap</a> data?</h3>
144
145<p>Because they are licensed under Creative Commons Share-alike
146licences, so we wouldn't be able to make our data public domain.</p>
147
148<p>There are people who believe that locating a point on a map creates a
149derived work, and hence requires a licence. We don't want to be the first
150to prove them wrong in a court, as that will be pricy.</p>
151
152<p>Also, the OpenStreetMap maps are not yet complete enough to achieve our
153goal of country-wide coverage.</p>
154
155
156<a name="freethepostcode"></a>
157<h3>Will this data be imported back into Free the Postcode?</h3>
158
159<p>Probably not directly. We are looking at the best way of presenting
160data from both projects whilst not polluting the Free the Postcode database
161with our lower accuracy data. We are importing Free the Postcode data into
162our database for display, but not re-exporting it currently.</p>
163
164
165<a name="accuracy"></a>
166<h3>If you are using scans of old maps, how accurate will the locations
167be?</h3>
168
169<p>Some of the scans are out by a degree or two but they are fairly
170good. We hope to be able to get better than 100 metres accuracy out of it in
171the end. This is more than good enough to locate a region as large as
172the first half of a postcode, and hopefully as much as the 'partial'
173postcodes described in the answer to 'What is it?' above.</p>
174
175
176<a name="houseMissing"></a>
177<h3>My house isn't on a 1950s map</h3>
178
179<p>Find some local landmarks and guess where your house is. This is
180accurate enough for our purposes.</p>
181
182
183<a name="gps"></a>
184<h3>I know exactly where I am, and what my postcode is</h3>
185
186<p>If you have a GPS, enter your data into <a
187href="http://www.freethepostcode.org">Free the Postcode</a> and make the
188world a better place.</p>
189
190
191<a name="islands"></a>
192<h3>I can't seem to find a certain island on your overview map</h3>
193<p>We've put together a list of <a href="islands.html">hard to find
194 islands</a>, so you might well be able to find it from there.</p>
195
196
197<a name="howToUse"></a>
198<h3>So, how do I use it?</h3>
199
200<p>Find your location on our map, click where your postcode is, enter
201the postcode, agreeing to release your data.</p>
202
203
204<a name="codepoint"></a>
205<h3>Psst, I have a copy of the codepoint database. Wanna look?</h3>
206
207<p>No thanks, we want free data so we don't have to keep paying the nice
208codepoint people. </p>
209
210<a name="otherdata"></a>
211<h3>Here's another source of free postcodes</h3>
212
213<p>There are many unattributed postcodes sets on the web, but none others
214(apart from freethepostcode.org, which we are already working with) which
215are unambiguously free. In particular there is a <a href="http://www.jibble.org/ukpostcodes/">site</a> which lots of people have pointed at. Unfortunately
216there is no actual data there; the data was removed after the Post Office
217issued a take-down notice to this site. We're only interested in public
218domain database (or possibly databases with other unambiguously "free"
219licensing terms).
220</p>
221
222
223<a name="codepointBusiness"></a>
224<h3>Won't you drive codepoint out of business?</h3>
225
226<p>We don't think so. There are a lot of places where this level of
227accuracy just isn't enough. Those people will still have to pay until
228<a href="http://www.freethepostcode.org">Free the Postcode</a> improves
229its coverage.</p>
230
231
232<a name="tileJoins"></a>
233<h3>The map doesn't join up.</h3>
234
235<p>Yes, it isn't perfect. The OS didn't publish a single map of the whole
236country, so you have to scan then stick together data from several maps.
237We don't really know how to correct it perfectly. It would be really cool
238if someone could write software to detect the gridlines and automatically
239cut the images up on the lines and make them square.</p> 
240
241
242<a name="helpOrthorectifying"></a>
243<h3>The wonkiness is so annoying it drives me mad, and I have experience of orthrectifying maps. Please let me straighten your maps.</h3>
244
245<p>Cool. Contact us, that would be great.</p>
246
247
248<a name="gdal"></a>
249<h3>Why didn't you use proj/gdal?</h3>
250
251<p>Because we don't know how to work them. If you feel like improving how this
252works, let us know. Update: We do use proj for the <a href="/postcodeine/">postcode display</a>.</p>
253
254
255<a name="scotland"></a>
256<h3>Why did it take you so long to have coverage of Scotland?</h3>
257
258<p>While the Ordnance Survey did create the New Popular Edition maps of
259 Scotland at 1 inch to the mile, these were never published, so we can't
260 buy them to scan in. Scotland was included in the Ordnance Survey
261 7<sup>th</sup> Edition at 1 inch to the mile, but almost all of these
262 maps remain in copyright for another few years, so we can't put them
263 online yet</p>
264<p>The Ordnance Survey did release some updates to the Popular Edition
265 of Scotland in the 1940s, which had the National Grid over-printed on.
266 them. (The War Office also published similar versions). While the grid
267 isn't parallel with the main map, it is possible to work with (just a
268 little bit more work). It has taken us much longer to track these down
269 than it took us to get the England and Wales New Popular Edition maps.
270 This is why we have only recently been able to offer a high degree of
271 coverage for Scotland.</p>
272
273<p>We now think we have completed our coverage of Scotland. Most of the
274 maps used are from the 1940s, but there are small numbers of earlier maps
275 (mostly 1920s), and small numbers of 7<sup>th</sup> edition maps from the
276 1950s. To see the coverage we have, visit the
277 <a href="/tiles/allmaps.html">large overview map.</a></p>
278
279
280<a name="northernIreland"></a>
281<h3>Why don't you have mapping data of Northern Ireland?</h3>
282
283<p>For Northern Ireland, the situation is harder than for Scotland,
284 because the Ordnance Survey of Northern Ireland didn't produce an
285 equivalent to the New Popular Edition, instead it produced a number of
286 updates without altering the name of the edition. So, many of the maps
287 from the Popular Edition of Northern Ireland are still in Copyright, so
288 it's hard to know if a given old map is out of copyright just from the
289 name.</p>
290<p>Compounding this, it is much harder to track down second hand maps
291 of Northern Ireland, compared to the difficulty of getting English,
292 Welsh and Scottish maps of the period. We have also yet to come across
293 any institutional holdings of old Northern Irish maps where the
294 holder will allow scans to be made. All we have been able to get is
295 quarter inch to the mile maps, which don't fit into our tiling scheme,
296 and are too small for finding postcodes on.</p>
297
298<p>If you would like to be notified when we do get out of copyright 1 inch
299 to the mile maps of Northern Ireland, please
300 <a href="scotlandAndNI.html">register your interest</a>.</p>
301
302
303<a name="who"></a>
304<h3>Who did the work?</h3>
305
306<ul>
307<li>Richard Fairhurst acquired and scanned the maps of England and Wales,</li>
308<li>Nick Burch, Andrew Rowbottom and Mike Calder have aquired and scanned
309 the maps of Scotland,</li>
310<li>Dominic Hargreaves, David Sheldon and Nick Burch straightened and tiled
311 the maps,</li>
312<li>Matthew Westcott, <a href="http://www.earth.li/~dave/">David Sheldon</a>,
313 Dominic Hargreaves and Nick Burch worked on the user interface and backend
314 software.</li>
315<li>Nick and Matthew's employer
316 <a href="http://www.torchbox.com">Torchbox</a> has supported the project
317 with some development time and design work.</li>
318</ul>
319
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