[Talk-us] Special issues in LA remap

Mike N niceman at att.net
Fri Jun 8 23:33:36 BST 2012

(I was going to talk about the Potlatch license display, but found that 
Potlatch2 still doesn't work for me - blank screen)


On 6/8/2012 4:49 PM, stevea wrote:
> I discern a vague remap plan ordering.  If you can, please sharpen this
> up or correct it if it is outright wrong:
> 1)  "The redaction bot" (still being written) will do much (to "ease in"
> the license change),
> 2)  "Nudge nodes to the location where they belong" is smartly next,
> somewhat unspecified as to how/where,

   The original TIGER import was of poor resolution.  To set context, 
'blars' originally lined up the streets with aerial imagery or gps 
tracks.  Most of his work shows up as node movements (yellow/orange 
nodes), with a few red nodes (new nodes he added to improve geometry). 
After the redaction bot runs, it will be clear on a grid against Bing 
aerial that the intersections are misaligned.   To remap those ways 
ahead of time, just center those roads and intersections against Bing 
aerial.  Even a tiny movement will be enough to clean those nodes. 
After a day or so, the license information should show as clean.

An example area is here:

    In JOSM, his edits in that area show mainly as orange nodes, with a 
few red nodes.  JOSM's "View History" shows that most of his edits to 
ways consisted of removing the 'tiger:reviewed=no' tag.   So the 
redaction bot will not change those ways at all.

> 3)  Perhaps update with TIGER 2011 data in select areas, also
> unspecified as to exactly where.

  Now that I've had a chance to look at the areas, I think I'd reserve 
use of TIGER 2011 for only new streets or mountainous,curvy roads with 
original poor geometry, or for streets that blars created or split and 
show as 'red'.   For gridded streets, it's almost certainly easier to 
just move the nodes instead of TIGER, usually to the center line of the 
aerial imagery.

> Why ask?  I remain vague how I should prioritize my remap efforts, and
> knowing redaction bot algorithm details helps me sharpen that up, I'm
> pretty sure.  (I am not alone).  Heck, it could also be true that work
> being done in the guts of these steps (does or will) make remap efforts
> less or even not necessary.  If so, a lot of people would appreciate
> seeing those words outright.  Or at least the necessary semantics to
> infer where our efforts are best invested in this project.  (We make
> these judgements for ourselves based upon data, preferably excellent data).

These are good questions, the case handling is outlined on the page, in 
the table "What taints data?".


   Other areas may result in a different recommendation; feel free to 
ask as those cases come up.   It's quite a complicated and unusual situation

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