source: trunk/npemap.org.uk/static/FAQ.html @ 252

Last change on this file since 252 was 252, checked in by Dominic Hargreaves, 14 years ago

Remove confusing title

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1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
2<html>
3<head>
4<title>FAQ | New Popular Edition Maps</title>
5</head>
6
7<body>
8
9<h3>What is it?</h3>
10
11<p>There are a lot of applications on websites for being able to tell where
12people are from their postcode. For example "Where is my nearest
13B&amp;Q?". Unfortunately this data is expensive to licence (a few
14thousand pounds/year for a website). <a
15href="http://www.freethepostcode.org">Free the postcode</a> are doing a
16good job, but it is hard to contribute to their database as you
17need a GPS, so they have few postcodes.</p>
18
19<p>Our goal is to collect postcode data by getting users to locate
20themselves on a map of the country. They need only give the first part
21of their postcode, and if we can collect locations for all of these
22parts then we can create a database that is good enough for many
23applications. We are also accepting complete postcodes and 'partial'
24postcodes including the number portion of the second half of the postcode,
25in order to improve our accuracy.
26</p>
27
28<h3>What licence will the data have?</h3>
29
30<p>The data will be will be in the public domain; consequently, users
31submitting data agree to their submission being in the public domain
32when they enter their postcode.</p>
33
34<h3>Where's the data, then?</h3>
35
36<p>We are still in the early stages of collecting data. We want to make
37sure that the data is in an appropriate format, that we have some quality
38control, and that we release the data in an appropriate format, before
39doing so.
40</p>
41
42<p>
43If you desperately want the data sooner, <a href="reportBug.html">get
44in touch</a>.
45</p>
46
47<h3>What maps are you using?</h3>
48
49<p>We have scans of out of copyright OS maps of England and Wales.
50You can <a href="scotlandAndNI.html">register interest in future
51projects involving Scotland and Northern Ireland</a>.</p>
52
53<h3>So can I do what I like with your scans/tiles?</h3>
54
55<p>
56No. The scans and tiles have been placed under a
57<a href="tileLicence.html">licence</a>; they are not in the public
58domain.
59</p>
60
61<h3>Okay; I can use the tiles for some things; can I download the complete set?</h3>
62
63<p>
64Not yet. We need to make sure we've uncovered all the obvious flaws with
65the current tiles (eg human error in cropping and numbering the tiles)
66and have worked out an efficient distribution format.
67<a href="reportBug.html">Let us know</a> if you want to
68use the tiles; please don't try and crawl our tileserver to obtain the entire
69set.
70</p>
71
72<h3>Isn't orthowotsiting an old map hard?</h3>
73
74<p>Luckily we're going to work in the OSGB coordinate system that
75matches up with the grid lines on the map; this means we don't have to
76distort the maps too much. We also are not overly fussy about the
77accuracy, so this step can be done quickly.</p>
78
79<h3>Why don't you use maps created from <a
80href="http://www.openstreetmap.org">OpenStreetMap</a> data?</h3>
81
82<p>Because they are licensed under Creative Commons Share-alike
83licences, so we wouldn't be able to make our data public domain.</p>
84
85<p>There are people who believe that locating a point on a map creates a
86derived work, and hence requires a licence. We don't want to be the first
87to prove them wrong in a court, as that will be pricy.</p>
88
89<p>Also, the OpenStreetMap maps are not yet complete enough to achieve our
90goal of country-wide coverage.</p>
91
92<h3>Will this data be imported back into Free the Postcode?</h3>
93
94<p>It might be, that will depend on someone working out how to store
95partial postcode data in Free the Postcode. We are importing Free the
96Postcode data into our database.</p>
97
98<h3>If you are using scans of old maps, how accurate will the locations
99be?</h3>
100
101<p>Some of the scans are out by a degree or two but they are fairly
102good. We hope to be able to get better than 100 metres accuracy out of it in
103the end. This is more than good enough to locate a region as large as
104the first half of a postcode, and hopefully as much as the 'partial'
105postcodes described in the answer to 'What is it?' above.</p>
106
107<h3>My house isn't on a 1950s map</h3>
108
109<p>Find some local landmarks and guess where your house is. This is
110accurate enough for our purposes.</p>
111
112<h3>I know exactly where I am, and what my postcode is</h3>
113
114<p>If you have a GPS, enter your data into <a
115href="http://www.freethepostcode.org">Free the Postcode</a> and make the
116world a better place.</p>
117
118<h3>So, how do I use it?</h3>
119
120<p>Find your location on our map, click where your postcode is, enter
121the postcode, agreeing to release your data.</p>
122
123<h3>Psst, I have a copy of the codepoint database. Wanna look?</h3>
124
125<p>No thanks, we want free data so we don't have to keep paying the nice
126codepoint people. </p>
127
128<h3>Won't you drive codepoint out of business?</h3>
129
130<p>We don't think so. There are a lot of places where this level of
131accuracy just isn't enough. Those people will still have to pay until
132<a href="http://www.freethepostcode.org">Free the Postcode</a> improves
133its coverage.</p>
134
135<h3>The map doesn't join up.</h3>
136
137<p>Yes, it isn't perfect. The OS didn't publish a single map of the whole
138country, so you have to scan then stick together data from several maps.
139We don't really know how to correct it perfectly. It would be really cool
140if someone could write software to detect the gridlines and automatically
141cut the images up on the lines and make them square.</p> 
142
143<h3>The wonkiness is so annoying it drives me mad, and I have experience of orthrectifying maps. Please let me straighten your maps.</h3>
144
145<p>Cool. Contact us, that would be great.</p>
146
147<h3>Why didn't you use proj/gdal?</h3>
148
149<p>Because we don't know how to work them. If you feel like improving how this
150works, let us know.</p>
151
152<h3>Why don't you have good mapping data of Scotland and Northern Ireland?</h3>
153
154<p>I don't think they were part of the New Popular Edition at 1 inch to the
155mile. If you have free higher resolution images of either of these places
156(we only have quarter inch to the mile) then we might be interested in them.</p>
157
158<h3>Who did the work?</h3>
159
160<ul>
161<li>Richard Fairhurst acquired and scanned the maps,</li>
162<li>Dominic Hargreaves and David Sheldon straightened and tiled the maps,</li>
163<li>Matthew Westcott, David Sheldon, Dominic Hargreaves and Nick Burch worked on the user interface and backend software.</li>
164</ul>
165</body>
166</html>
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