Month: May 2006

Categories
GIS opensource

Copyright free mapping is coming..

Like a spurned lover, I was beginning to feel neglected having been ignored last week by the Guardian’s “Free our Data Campaign”, but this week we are back to normal with a piece describing the efforts of the OpenStreetMap team to Map the Isle of Wight last weekend.

In the past I have made it clear that I am fully behind the efforts of Steve Coast and the OpenStreetMap movement to create copyright free mapping, the technology is here today and with some bright people and organisation it is completely practical to produce a national street database for Great Britain.

As Jeff points out in his blog, National Mapping Agencies such as the OS need to wake up to these community driven developments, however I really think we must see them not as a threat, but as an opportunity.

Will Steve Coast be the Linus Torvalds of open source geodata ? time will tell, but I believe OpenStreetMap is every-bit as important a development in Geospatial data as the development of the Linux Kernel was for operating systems, and I suggest ultimately a similar commercial model may develop around open source geospatial data.

There is without question a place for open source “small” scale data, without the high spatial resolution, rich data models and high levels of currency which characterise products like OS MasterMap.

Open Source geospatial data products will meet the needs of many users who just need to be able to produce simple location maps and which need to be updated less frequently. But even these maps will need to be updated..

Keeping such datasets up to date, is a lot more difficult but potentially possible.. however it may need a more robust long term funding stream to support the process, keeping servers running and bandwidth costs real money.

This does boil down ultimately to the old “Free as in Speech” or ‘Free as in Beer” debate, copyright free or open source mapping may well ultimately migrate to the former position – copyright free but commerical supported in some way, this I think is still very positive for the Gi Industry, with many opportunities for commercial support and value add services.

Such a “free as in Speech” dataset supported by a robust commercial model may well meet the needs of the user community, but I not sure it will go far enough for the “free our data’ campaign which is more politically motivated.

In conclusion we must recognise that open source geodata is here to stay and is real, Mapping Agencies such as the OS must learn to adopt it’s values and meet the needs of a user community not fully served today.

Actually I really do see a role for the OS in contributing to open source databases in the future, copyright free street maps are a great starting point, but it would be great to have urban area boundaries and a coastline, for example, contributed by the OS?

btw – I appreciate the efforts of guys last weekend to make sure they were not using “in-copyright” maps of the Isle of Wight, but I think the Map of Namibia used by the guys in the articles photograph is taking things a bit too far !!

Written and submitted from home, using my home 802.11 network.

Categories
GIS GPS Technology Thoughts

London Black Cabs add GPS

Evening Standard

This evenings Evening Standard, London’s evening newspaper reports that for the first time London’s Black Taxi Cab drivers are to be allowed to supplement they “Knowledge” of the streets of London with GPS navigation systems.

For the Public Carriage Office, not an organisation known for its grip on technology (have you ever tried to pay by credit card in a London Taxi ?) to adopt this is a massive leap forward.

This could get interesting.. is the navigation system a match for the encyclopaedic knowledge of you average London taxi driver, I actually doubt it, the intricate knowledge of the streets of London and how congested they are likely to be at any point of time is something very difficult to capture at present – another “sense of place” type of data where traditional GI approaches fail.

Still there is no longer an excuse to hear.. “Sorry Guv, Can’t go south of the river!”

Written and submitted from home, using my home 802.11 network.

Categories
GIS Thoughts

Did you feel the earth move..

I’ve just got back from the inaugural meeting of the British Computer Society’s Geospatial Interest Group, another example of GI hitting the mainstream. I was asked a number of questions on positioning technology and the accuracy of data, which reminded me that the OS has just completed it’s Positional Accuracy Improvement (PAI) programme.

Like most other national mapping agencies and other creators of national geospatial data products, the data contained in the OS National Database dates from a time before absolute positioning technology, where the location of a feature was ‘measured’ relative to a fixed control network and other “stable” geographical features.

For most purposes this has not been a problem, however with the introduction of GPS and the fact that the data was originally collected using local country projection systems, random location errors of up to 10 metres became obvious in rural areas.

The OS was left with the dilemma, ignore the issue – or correct it. This is not as obvious a decision as you might expect, in the UK most organisation who had captured they own information had done so in relation to features as positioned on OS maps, and these features might now be moving.

There really was no choice for the OS, as with many other organisations the widespread use of GPS meant the data has to be corrected, so five years ago the project was started and it was completed last month !

Out of the 244,000 sq Km of Great Britain, over 160,000 sq km had to be corrected using photogrammetric survey to increase positional accuracy to around a metre in most cases. To allow user defined data to be adjusted geometrically, no less than 450 million change vectors have been calculated for use in transformation software.

The OS may be one of the first organisation to address this issue, but I’m sure many other organisations will have to follow the example, the relative accuracy’s of mapping data used in the early days of digital cartography are no longer ‘fit for purpose” in the era of widespread GPS use, so for many people the earth may well be moving!

Written and submitted from home, using my home 802.11 network.