[OHM] Historic places versus confidence

[Rob Warren]

I've been looking at the OSM documentation. It would seem that we can  
use start_data and end_date for both ways and relations. It might make  
things easier to have ways (de)activate based on the date where things  
changed and have the relation live on through different incarnations.

Keep in mind through that datums are messy (even in WGS84), you are  
unlikely to notice the San Francisco slip unless your data source is  
very good. Maps in the early 1900 had limited accuracy; the ones I  
used were aiming for ~20 yards.

This brings the annoying question of whether we should be recording  
accuracy of ways / node positions. I've been searching the OSM wiki  
for standards and/or best practices about this without any success.  
Any ideas out there?


best,
rhw

On 4-Mar-13, at 4:26 PM, johnny0 wrote:

> It's not just shifting borders.  What about changing physical  
> geography?
>
> How best to handle changing coastlines over time? I'm thinking of  
> sunken Roman era ports.
>
> http://ac-support.europe.umuc.edu/~jmatthew/naples/pozzport.htm
>
> As well as man-made land:
>
> http://blog.sfgate.com/ontheblock/2011/02/25/does-your-house-sit-on-landfill/
>
> Also, shifting rivers:
>
> http://blogfishx.blogspot.com/2011/05/will-mississippi-river-change-course.html
>
> And what about earthquakes? There was 2 to 32 feet of horizontal  
> slip in the 1906 San Francisco earthquake.
>
> http://earthquake.usgs.gov/regional/nca/virtualtour/earthquake.php
>
> This last one is tricky.
>
> -John
>
> On 2013-03-04, at 12:07 PM, Rob Warren <warren at muninn-project.org>  
> wrote:
>
>>
>> I'd like to get it to that point, especially in recording the  
>> changes in the spatial objects over time.
>>
>> The other issue is that while a contributor might add the border of  
>> the Kingdom of Prussia and another the border of the Free State of  
>> Prussia, the ways that are common to both objects will eventually  
>> need to be merged. This is going to require some creativity, but it  
>> is doable. I also suspect that eventually we'll have a few  
>> different 'application websites' that use the OHM back-end for  
>> storage but render application specific timelines only.
>>
>> I'd suggest we start by putting in some data and we'll build the  
>> tools as we go along.
>>
>> rhw
>>
>>
>> On 28-Feb-13, at 9:11 PM, historic-request at openstreetmap.org wrote:
>>
>>> Message: 2
>>> Date: Thu, 28 Feb 2013 16:52:27 -0600
>>> From: Ed Dykhuizen <eddykhuizen at gmail.com>
>>> To: Burrito Justice <burritojustice at oram.com>
>>> Cc: "historic at openstreetmap.org" <historic at openstreetmap.org>,  
>>> Joseph
>>> 	Pettigrew <pettigrj at hotmail.com>
>>> Subject: Re: [OHM] [Historic] Historic Digest, Vol 7, Issue 9
>>> Message-ID:
>>> 	<CAHDqN=8gEhHzJeazX6-s8RCu00uE0B- 
>>> wdiqbqdZPnK9mYLDZbA at mail.gmail.com>
>>> Content-Type: text/plain; charset="iso-8859-1"
>>>
>>> Hi all,
>>>
>>> I don't know if I should be counted towards any quorum of any kind  
>>> -- I'm
>>> not a developer, just someone interested in this topic and very  
>>> happy to
>>> see it being pursued. Specifically, I had an idea a while ago about
>>> creating political maps for each year throughout history. So you  
>>> could look
>>> at a political map of Europe around 343 BC and then move a dial  
>>> towards the
>>> same area around 323 BC and see how the political map changed as  
>>> Alexander
>>> the Great went on his conquerin' spree. I'm a big history fan, and  
>>> more of
>>> a visual learner, so something like this would really help me  
>>> solidify a
>>> lot of world history.
>>>
>>> Granted, creating political maps for every year in history is a  
>>> Herculean
>>> task. So I was hoping someone could develop an interface that  
>>> would allow
>>> non-tech-savvy people like myself to make such changes. You know,  
>>> something
>>> where I could go to the map of 343 BC and draw and then manipulate a
>>> boundary like you do in Photoshop. Maybe I could then put in some
>>> placemarks for specific events that then link to Wikipedia  
>>> articles about
>>> them. Then when I'm done I could hit upload and see the changes on  
>>> a master
>>> set of maps that anyone can work on. If it were that easy you  
>>> could maybe
>>> get a lot of history buffs to do the work for free, a la Wikipedia.
>>> Teachers in particular might be interested because the end product  
>>> could
>>> really help in teaching history.
>>>
>>> I've been reading the emails to try to figure out if something  
>>> like this is
>>> in the works, but I admit, there's so much that's over my head  
>>> that I just
>>> get lost. Does any of what I'm describing sound like anyone's plans?
>>>
>>> Thanks so much for reading this,
>>>
>>> Ed Dykhuizen
>>>
>>> (And I'm including my friend Joe on this -- hope you don't mind!)
>>
>>
>> _______________________________________________
>> Historic mailing list
>> Historic at openstreetmap.org
>> http://lists.openstreetmap.org/listinfo/historic
>