[RNFdev] Some thoughts of FSA Centroids and Polygons

[Sampson, David]

I guess my brain storm made sense to only my brain. 

I'll try to clarify. Some abstract thought was probably involved in my
brain.

The polygons I originally referred to were polygons created by the
thinned out RNF.... When a network of roads create a filled in shape
this can be thought of as a polygon. So changing the road network to a
series of polygons. This is obviously an imperfect method for all areas,
but may work well for the urban areas.

Then the FSA centroids will occur SOMEWHERE within these polygons...

These FSA centroids can act as vector polygon labels. These labels hold
the attribute data about a particular polygon.

1. Change vector lines to polygons
2. clean danglers and overshoots (loose ends that extend PAST an
intersection
3. investigate undershoots (where two lines have not meta and require a
virtual extension or more data
4. Attribute tabular data through the FSA centroid as labels
5. investigate tagged polygons as bellow

Does this make more sense?

What is your unfeasible idea? 


-----Original Message-----
From: Dan Putler [mailto:putler at sauder.ubc.ca] 
Sent: September 27, 2006 16:43
To: can_rnf at geodata.osgeo.org
Subject: Re: [RNFdev] Some thoughts of FSA Centroids and Polygons

Hi Dave,

I'm unclear on a couple of things. You indicate:
> The thought is
>
> 1. Create the reduced RNF
> 2. Create the FSA Centorids
> 3. in a GIS import both the reduced RNF and the FSA centroids 4. do 
> some queries:
>         a. find all polygons with one FSA point
>         b. find all polygons with more than one FSA point
>         c. find all polygons lacking any FSA tag 5. use this info to 
> help with manual edits.
What I'm confused about two things. First, which polygons are you
referring to above? The reduced RNF contains only road segments and
other lines (not polygons), FSA centroids contains only points, or are
you referring to the CSD polygons? The mention of FSA centroids leads to
my second question, specifically, are the FSA centroids the ones
available from geoconnections? If yes, they appear to have some accuracy
issues.

I've also been thinking about other things we could that would be easier
than creating FSA polygons. I have an idea, but I don't know if it
feasible.

Dan

> From that we can hypothesise that in
>         case A the polygon is either correct (requiring some manual  
> cleaning) or requires enlargement (manual merges maybe)
>
>         case B the polygon requires additional information such as  
> other non-road features
>         case C the polygon has been split too much and something  
> needs to be blown away.
>
> Some of this might be able to be automated or atleast again a  
> probability choices made.
>
> Any thoughts
>