[Talk-us] Whole world files

[F Hillhouse Jr]

> >> > Greetings,
> >> >
> >> > I just joined this list. I looking forward to learning more
> >> about what
> >> > is going on and providing help somewhere in the future.
> >> >
> >> > In the meantime, I found files for the whole world and also
> >> for some
> >> > limited areas. What I was looking for was files
> >> specifically for the
> >> > USA. I was thinking along the lines of grid squares, like
> >> FN43 (maidenhead).
> >> >
> >> > Does anyone know if these subsets might be available?
> >> >
> >> > As a follow up, if I downloaded a world file and 
> unzipped it, would 
> >> > the directories and files be in the "slippy" format?
> >> >
> >> > Downloading the entire world is pretty much pointless for
> >> me since I
> >> > spend my time in the 6 states of New England (ME, NH, VT,
> >> MA, RI, CT).
> >> >
> >> > Thank you for considering my questions!
> >>
> >> Hi Fred, and welcome.
> >>
> >> There are subsets that we call 'extracts' of the planet file 
> >> available for smaller areas of interest.  Some tips and background 
> >> here.
> >> http://weait.com/content/openstreetmap-extracts
> >> http://weait.com/content/combine-openstreetmap-extracts
> >>
> >> When you download the planet, or extracts, they are 
> usually in OSM's 
> >> xml format.  So, no, not images for a slippy map.
> >> Other formats are available, like pre-built files for Garmin GPS 
> >> receivers, and others.
> >>
> >> So, welcome again and enjoy.
> >>
> >
> > Hi Richard,
> >
> > After reading through the different pages available there, 
> I am still 
> > clueless of a direction to go..
> >
> > I will tell you a bit about the application I am using and maybe 
> > another clue from you may help.
> >
> > The application (APRSIS32) that I am uses the OSM tiles for 
> display. 
> > As I move the map about, tiles are grabbed it they are not local. I 
> > would guess you are very familiar with these 256x256 tiles.
> >
> > I have been retrieving tiles using two methods; move the 
> map manually 
> > and let the application grab them or moving the map via a GPS 
> > simulator. The first method is tedious and I have to move 
> to each zoom 
> > level to get appropriate tiles. The second, I create a file of the 
> > path to follow. This is not too bad since it can run 
> unattended. I do 
> > have to run for each zoom level.
> >
> > What would you suggest?
> >
> > Thanks!
> > Fred
> 
> Dear Fred,
> 
> That program you are using, is that related to the APRS 
> amateur radio stuff?  Sounds like great fun.
> 
> The OSM planet file, and the OSM extracts are in OSM XML 
> format.  They are not the slippy map tiles.  I'm not aware of 
> anybody who prepares slippy map tile extracts for areas like 
> the US North East.
> 
> I would caution you about using an automated method of 
> retrieving tiles from the OSM server.  First, there is a 
> potential problem that you would download a row before an OSM 
> update and the next row after the update.  That might give 
> you adjacent tiles that don't line up.
> That's a minor consideration even though OSM updates happen 
> many times per second.
> 
> The largest concern that I have is that automated downloads 
> of large numbers of OSM tiles makes a large and noticeable 
> load on the OSM servers.  There are times that the server 
> administrators will notice this unusual load from a single 
> user, and that their load is adversely affecting other OSM 
> users.  They can and will block users who adversely affect 
> other users.
> 
> The tile usage policy is here, as well as some suggestions 
> for alternatives to scraping tiles from the server.
> http://wiki.openstreetmap.org/wiki/Tile_usage_policy
> 
> Those alternatives include 1) building your own tile server, 
> or 2) using a commercial provider of OSM tiles.
> 
> I'll have a quick look here and see how much time and space 
> it would take me to create those tiles for you.  I'll let you 
> know shortly.
> 

Hi Richard,

It is for APRS Amateur radio stuff. I have a mountain top (1250'=mountain?)
digipeater running as well as my mobile rig. My mobile rig is offline (not
on the internet) 99.9% of the time so I try to grab tiles in advance to an
area I am planning on visiting. The software was originally designed for a
mobile phone, which is always online, but has been extended to a
desktop/laptop environment. The mobile phone is only grabbing tiles based on
movement and zoom level of the immediate area around it.

I did read that link and I would hate to be excluded!

At lunch, I run my simple GPS simulator that reads in a latitude and
longitude and sends it out one serial port which is looped back into a
second one. I send a position for each minute of angle and let APRSIS32 do
its job. I don't usually go for more than 1/4 of a grid square at a time.
The time per position is usually between 3 and 10 seconds depending on how
long everything is taking. That may be depending on the tile server. I don't
know for sure. If I let it run over night the time increment is at least 10
seconds. I also don't do this everyday. I figure on occasion I will have an
old tile as well.

I have been using the Terra Server tile set and the tiles don't always line
up either. I have learned to deal. ;)

I was hoping the 'Planet' file was tiles. It is starting to sound like a
large map that tiles can be extracted from. In which case, the most
efficient way might be to download the file and extract them here.

I will have to look into doing a file server. I assume that others could
download tiles from it as well. This actually seems like a good place for
something like bit-torrent to be used. I have never used it but basically
understand one server becomes part of a larger system. I don't have a Linux
machine. So that would be a new experience too.

Thanks!
Fred