Sounds good and it is a start. So, we don't need any database to start the PD project. Great!<br><br>How do we ensure that two contributors don't modify the same osm file at the same time? Do we need a file locking mechanism?<br>
<br>I suppose this would be a temporary solution for GPX files and OSM files until we get a real OSM server running?<br><br>- Kari<br><br><div class="gmail_quote">2008/11/7 Sunburned Surveyor <span dir="ltr"><<a href="mailto:sunburned.surveyor@gmail.com" target="_blank">sunburned.surveyor@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Joseph wrote: "Heh - not many people will comment for this reason:<br>
<a href="http://www.bikeshed.com/" target="_blank">http://www.bikeshed.com/</a>"<br>
<br>
Understood. I was just trying to build some consensus before making<br>
unilateral moves. That got me into trougle with the mailing list idea.<br>
:]<br>
<br>
Joseph wrote: "How many directories does that create in the repository? 1/4 of a<br>
<div>degree per makes it sound like a lot."<br>
<br>
</div>Since there are 360 degrees of longitude we are talking about (in<br>
theory) <4*360> 1080 longitude folders. Each longitude folder would<br>
have (in theory) <180*4> 720 latitude folders. That would be a total<br>
of 777,600 folders. I agree that is a lot. However, you'd need to<br>
subtract out the folders for the oceans, other large bodies of water<br>
and places like Antartica, where we aren't likely to do any mapping.<br>
<br>
I thought we would only create the directories as they were needed. If<br>
a new PD enthusiast joined the project and wanted to contribute in an<br>
area that wasn't covered by a folder, we'd create it in the repository<br>
so that if fit in the folder structure I defined. This wouldn't be<br>
hard at all.<br>
<br>
Joseph wrote: "Surely more than any human can<br>
manually manage."<br>
<br>
I think a simple software tool could assist with the downloading of<br>
data for a particular area of interest. I'm just looking for a logical<br>
folder structure. There would be some interesting problems, however,<br>
like a road segment that falls within two (2) cells. I'm still<br>
thinking about how to handle that situation. Perhaps we put the road<br>
semment in the cell that contains the majority of the road segment<br>
geometry?<br>
<br>
Joseph wrote: "Another way we could do it is make quad-trees out of<br>
<div>directories. If<br>
you imagine the root directory contains the whole planet, then four<br>
subdirectories each with 1/4 of the world map... and they each contain<br>
4 directories which quarter the regions again and so on to some<br>
particular detail level."<br>
<br>
</div>That is an interesting concept. The only disadvantabe with this<br>
approach is it couldn't be built incrementally as we expand our<br>
coverage. (At least, I don't think it could.)<br>
<br>
I will inquire about the possibility of hosting a sample OSMPD<br>
repository like the one I described at the OSGeo, and will report back<br>
to the list.<br>
<br>
The Sunburned Surveyor<br>
<div><div></div><div><br>
On Thu, Nov 6, 2008 at 2:42 PM, Joseph Gentle <<a href="mailto:josephg@gmail.com" target="_blank">josephg@gmail.com</a>> wrote:<br>
> Heh - not many people will comment for this reason: <a href="http://www.bikeshed.com/" target="_blank">http://www.bikeshed.com/</a><br>
><br>
> How many directories does that create in the repository? 1/4 of a<br>
> degree per makes it sound like a lot. Surely more than any human can<br>
> manually manage. I guess the trick is that people only need to check<br>
> out a few of the directories dependent on where they live (which is<br>
> kinda nice).<br>
><br>
> Another way we could do it is make quad-trees out of directories. If<br>
> you imagine the root directory contains the whole planet, then four<br>
> subdirectories each with 1/4 of the world map... and they each contain<br>
> 4 directories which quarter the regions again and so on to some<br>
> particular detail level.<br>
><br>
> I'm not sure if it buys you much, and again you'll have a lot of directories.<br>
><br>
> -J<br>
><br>
><br>
> On Fri, Nov 7, 2008 at 2:33 AM, Sunburned Surveyor<br>
> <<a href="mailto:sunburned.surveyor@gmail.com" target="_blank">sunburned.surveyor@gmail.com</a>> wrote:<br>
>> I've attached a zip file with a proposed OSMPD data repository folder<br>
>> structure. This is only an idea of what we could do. I know there will<br>
>> be lots of other ideas on how we could set something up, or<br>
>> modifications of my proposal. I just want to help move things forward<br>
>> with a productive discusssion. :]<br>
>><br>
>> Here is a brief explanation of how the folder structure is designed:<br>
>><br>
>> The top level of the repository is divided into folders that represent<br>
>> areas of the globe that cover 1/4 a degree of longitude. So, for<br>
>> example, the folder W-119-00 contains all of the data between the west<br>
>> longitude of 119-00-00 and 119-15-00. Each of these longitude folders<br>
>> contains subfolders that cover 1/4 a degree of latitude within the<br>
>> strip of longitude covered in the parent folder. In this way the globe<br>
>> is divided into a grid of 1/4 degree "cells".<br>
>><br>
>> Each cell has the following subfolders:<br>
>><br>
>> gpx_files<br>
>> history<br>
>> metadata<br>
>> osm_files<br>
>> supplemental_data<br>
>> raster<br>
>> vector<br>
>> photos<br>
>><br>
>> The "gpx_files" folder will contain raw GPS data in GPX format.<br>
>> The "history" folder can contain versioning information and/or<br>
>> information on additions and changes to the data in the cell.<br>
>> The "metadata" folder can contain metadata files for the data in the cell.<br>
>> The "osm_files" folder will contain OSM files produced from the GPX files.<br>
>> The "supplemental_data" folder can contain other PD data that can<br>
>> assist in the mapping efforts. In the United States this would likely<br>
>> include USGS quad maps and TIGER shapefiles, but it might also contain<br>
>> public domain data from other sources. In different places of the<br>
>> world other types of public domain data might be stored here.<br>
>> The "photos" folder would contain digital pictures of the features<br>
>> that had been/were being mapped in the cell.<br>
>><br>
>> I think only the "Gpx_files" and "osm_files" folders would be required<br>
>> to contain data. The other folders would be for the optional use of<br>
>> those working together on data within a "cell". Perhaps, over time,<br>
>> individual working within the same region could agree on a basic<br>
>> structure for these optional folders and there contents. The content<br>
>> and structure of these cells would vary by region. A naming convention<br>
>> for photos might also be helpful, and I can see having a standard<br>
>> format for a simple text file with photo descriptions.<br>
>><br>
>> It would be possible to write simple tools to work with this type of<br>
>> folder structure. For example: I could write a plug-in for OpenJUMP<br>
>> that would do the following:<br>
>><br>
>> - Allow the user to input latitude/longitude coordinates for an area<br>
>> of interest.<br>
>> - Merge the OSM or GPS files in the zones that cover this area into<br>
>> single files for the area of interest.<br>
>> - Load and display these files in the map view on OpenJUMP.<br>
>><br>
>> I still think it would be a good idea to appoint volunteer "Cell<br>
>> Coordinators" that could over see the contents of each cell folder and<br>
>> help coordinate mapping efforts within the cell. I believe this would<br>
>> help improve the quality and organization of the OSMPD data<br>
>> repository.<br>
>><br>
>> I am eager to get some type of folder structure determined and put<br>
>> online so I can have a place to put my data.<br>
>><br>
>> OK. Now you can tear my proposal apart! :]<br>
>><br>
>><br>
>> The Sunburned Surveyor<br>
>><br>
>> P.S. - To view the complete folder structure in the attached zip file<br>
>> you need to click on the W-121-00 longitude folder and then the<br>
>> N-37-00 latitude folder. This folder is the one that covers my home<br>
>> town.<br>
>><br>
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>><br>
><br>
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