[Talk-GB] OS and OSM

[Ed Avis]

Tom Chance <tom at ...> writes:

>Steve, In Southwark I experimented with bulk importing buildings auto-traced
>from OS StreetView, but gave up in favour of manually tracing from Bing
>imagery.

In fairness you should mention that the Bing imagery was not available at the
time of the original OpenData release.  It's clear that the simplified Street
View building shapes are inferior to high-res aerial photos that Bing has
let us use.  But back when we only had the low-res Yahoo photos, the Street View
building shapes were very useful and typically superior to the early OSM
building tracing efforts.

You mentioned errors in OS Locator, and it does indeed have some, but typically
fewer errors than a single-pass ground survey (this based on my experience
rechecking mismatches across London).

It is great to do a ground survey and then use OS Locator to check for mistakes,
but it would be equally possible to populate names from OS Locator and then do
a ground survey to check for mistakes.  The total amount of work involved is the
same, but by kick-starting from the OS data you get to the 90% mark faster, even
though the final 10% takes time.  Again, I would re-iterate that the OS Locator
names usually have a lower error rate than OSM ground surveys, so I would have
more confidence in a street name populated from OS only than in one that had been
found on the ground but not checked against OS.

-- 
Ed Avis <eda at waniasset.com>