source: trunk/npemap.org.uk/static/FAQ.html @ 138

Last change on this file since 138 was 138, checked in by Dominic Hargreaves, 14 years ago

Errant full stop.

File size: 6.1 KB
Line 
1<html>
2<head>
3<title>FAQ | New Popular Edition Maps</title>
4</head>
5
6<body>
7
8<h2>Free the postcode lite</h2>
9
10<h3>What is it?</h3>
11
12<p>There are a lot of applications on websites for being able to tell where
13people are from their postcode. For example "Where is my nearest
14B&amp;Q?". Unfortunately this data is expensive to licence (a few
15thousand pounds/year for a website). <a
16href="http://www.freethepostcode.org">Free the postcode</a> are doing a
17good job, but it is hard to contribute to their database as you
18need a GPS, so they have few postcodes.</p>
19
20<p>Our goal is to collect postcode data by getting users to locate
21themselves on a map of the country. They need only give the first part
22of their postcode, and if we can collect locations for all of these
23parts then we can create a database that is good enough for many
24applications. We are also accepting complete postcodes and 'partial'
25postcodes including the number portion of the second half of the postcode,
26in order to improve our accuracy.
27</p>
28
29<h3>What licence will the data have?</h3>
30
31<p>The data will be will be in the public domain; consequently, users
32submitting data agree to their submission being in the public domain
33when they enter their postcode.</p>
34
35<h3>Where's the data, then?</h3>
36
37<p>We are still in the early stages of collecting data. We want to make
38sure that the data is in an appropriate format, that we have some quality
39control, and that we release the data in an appropriate format, before
40doing so.
41</p>
42
43<p>
44If you desperately want the data sooner, <a href="reportBug.html">get
45in touch</a>.
46</p>
47
48<h3>What maps are you using?</h3>
49
50<p>We have scans of out of copyright OS maps of England and Wales.
51You can <a href="scotlandAndNI.html">register interest in future
52projects involving Scotland and Northern Ireland</a>.</p>
53
54<h3>So can I do what I like with your scans/tiles?</h3>
55
56<p>
57No. The scans and tiles have been placed under a
58<a href="tileLicence.html">licence</a>; they are not in the public
59domain.
60</p>
61
62<h3>Okay; I can use the tiles for some things; can I download the complete set?</h3>
63
64<p>
65Not yet. We need to make sure we've uncovered all the obvious flaws with
66the current tiles (eg human error in cropping and numbering the tiles)
67and have worked out an efficient distribution format.
68<a href="reportBug.html">Let us know</a> if you want to
69use the tiles; please don't try and crawl our tileserver to obtain the entire
70set.
71</p>
72
73<h3>Isn't orthowotsiting an old map hard?</h3>
74
75<p>Luckily we're going to work in the OSGB coordinate system that
76matches up with the grid lines on the map; this means we don't have to
77distort the maps too much. We also are not overly fussy about the
78accuracy, so this step can be done quickly.</p>
79
80<h3>Why don't you use maps created from <a
81href="http://www.openstreetmap.org">OpenStreetMap</a> data?</h3>
82
83<p>Because they are licensed under Creative Commons Share-alike
84licences, so we wouldn't be able to make our data public domain.</p>
85
86<p>There are people who believe that locating a point on a map creates a
87derived work, and hence requires a licence. We don't want to be the first
88to prove them wrong in a court, as that will be pricy.</p>
89
90<p>Also, the OpenStreetMap maps are not yet complete enough to achieve our
91goal of country-wide coverage.</p>
92
93<h3>Will this data be imported back into Free the Postcode?</h3>
94
95<p>It might be, that will depend on someone working out how to store
96partial postcode data in Free the Postcode. We are importing Free the
97Postcode data into our database.</p>
98
99<h3>If you are using scans of old maps, how accurate will the locations
100be?</h3>
101
102<p>Some of the scans are out by a degree or two but they are fairly
103good. We hope to be able to get better than 100 metres accuracy out of it in
104the end. This is more than good enough to locate a region as large as
105the first half of a postcode, and hopefully as much as the 'partial'
106postcodes described in the answer to 'What is it?' above.</p>
107
108<h3>My house isn't on a 1950s map</h3>
109
110<p>Find some local landmarks and guess where your house is. This is
111accurate enough for our purposes.</p>
112
113<h3>I know exactly where I am, and what my postcode is</h3>
114
115<p>If you have a GPS, enter your data into <a
116href="http://www.freethepostcode.org">Free the Postcode</a> and make the
117world a better place.</p>
118
119<h3>So, how do I use it?</h3>
120
121<p>Find your location on our map, click where your postcode is, enter
122the postcode, agreeing to release your data.</p>
123
124<h3>Psst, I have a copy of the codepoint database. Wanna look?</h3>
125
126<p>No thanks, we want free data so we don't have to keep paying the nice
127codepoint people. </p>
128
129<h3>Won't you drive codepoint out of business?</h3>
130
131<p>We don't think so. There are a lot of places where this level of
132accuracy just isn't enough. Those people will still have to pay until
133<a href="http://www.freethepostcode.org">Free the Postcode</a> improves
134its coverage.</p>
135
136<h3>The map doesn't join up.</h3>
137
138<p>Yes, it isn't perfect. The OS didn't publish a single map of the whole
139country, so you have to scan then stick together data from several maps.
140We don't really know how to correct it perfectly. It would be really cool
141if someone could write software to detect the gridlines and automatically
142cut the images up on the lines and make them square.</p> 
143
144<h3>The wonkiness is so annoying it drives me mad, and I have experience of orthrectifying maps. Please let me straighten your maps.</h3>
145
146<p>Cool. Contact us, that would be great.</p>
147
148<h3>Why didn't you use proj/gdal?</h3>
149
150<p>Because we don't know how to work them. If you feel like improving how this
151works, let us know.</p>
152
153<h3>Why don't you have good mapping data of Scotland and Northern Ireland?</h3>
154
155<p>I don't think they were part of the New Popular Edition at 1 inch to the
156mile. If you have free higher resolution images of either of these places
157(we only have quarter inch to the mile) then we might be interested in them.</p>
158
159<h3>Who did the work?</h3>
160
161<p>
162<ul>
163<li>Richard Fairhurst acquired and scanned the maps,</li>
164<li>Dominic Hargreaves and David Sheldon straightened and tiled the maps,</li>
165<li>Matthew Westcott, David Sheldon, Dominic Hargreaves and Nick Burch worked on the user interface.</li>
166<ul>
167</body>
168</html>
Note: See TracBrowser for help on using the repository browser.