[Talk-GB] New users and P2

David Woolley forums at david-woolley.me.uk
Fri Feb 26 13:03:38 UTC 2016


On 26/02/16 12:44, Chris Hill wrote:
> I disagree. GPS traces can only be found by being on the ground. Aerial
> imagery is useful but being there and seeing what is really on the
> ground is still the gold standard in my view. Aerial imagery is not
> guaranteed to be well aligned, is guaranteed to be be steadily more and
> more out of date and gives no clue about what signs say. Mapping by
> surveying gives such a good understanding of what is really there that
> it is the best way to integrate your new stuff and perhaps correct what
> may have been added by the folks who have gone before.

The proposal appeared to be for a tool that only used the GPS traces and 
went straight from them to the database.  My point is that these days 
you need to integrate the GPS traces with the aerial imagery and with 
what is already mapped.

If you don't integrate with the aerial imagery, you will end up with a 
feature with large errors which won't get corrected for a long time 
because people will assume that they do account for all data sources.

If you don't integrate with existing features, you will end up with 
topological errors and possible duplication.

Whilst the GPS tagged ground survey is important, it needs to be 
integrated with the other sources and the only current way of doing that 
well involves the use of wetware and tools that show the other resources.



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