Re: [aprsisce] Re: maps
- Warning: Semi-negative posting ahead, but it's the facts as I see them.
On 6/27/2013 3:18 PM, Michael Hojnowski wrote:
Yes, I've been wondering about this too. I would like to cache maps on my laptop to use in my car, as I do a long road trip. I don't want to depend on (or pay for) cellular data to download as I go. I'll be crossing into Canada on one of these trips, and roaming data is prohibitively expensive.
APRSISCE/32 isn't fundamentally a mapping application. It's an APRS application that happens to use maps as a background for its data display. The maps it uses are freely available from data accumulated by the OpenStreetMap effort. The DATA behind the maps is free. The tile servers that share out the visual representation of that data are also free, but only within a strict usage policy.
A friend suggested I run the gpx route at several different levels of zoom to build the tiles I want. This seems a little clunky. I completely understand the reasoning, if I was running this app on my phone, but I'm running it on a dedicated laptop with a terabyte drive.
It may be clunky, but it actually has nothing to do with where you're running the application, but everything to do with where the map tiles are coming from. Please read http://wiki.openstreetmap.org/wiki/Tile_usage_policy
A Garmin doesn't have a heluva lot of space, but it stores a LOT of map data.
And lots of people pay a reasonable sum of money each to Garmin to a) get their original map data and even more to b) keep that map data up to date. If I had a few million users popping $150 initially and $30-$70 annually, you can bet we wouldn't be having this discussion!
I don't know if it would be a major re-engineering, but a desirable feature to me would be to download "all" the map data, and have it on my hard drive all the time. If tiles have to be ripped from it as I go, that's probably fine on my laptop. It's just sitting there doing not much as I drive. and a laptop has more horsepower than a handheld device.
Right. I do have plans to do almost that. My own OpenStreetMap tile server hosts a 250GB+ database on SSD media and spends 15-30 minutes every 4 hours keeping that data up to date with the latest changes to the OSM planetary database. And then it cranks out 100% of the 4 cores I allow it to use whenever I actually want to SEE that data rendered onto map tiles. If I happen to shut it down for a few days (on purpose or accidentally), it plays havoc trying to catch up to current.
You're laptop may not be doing anything, but it actually doesn't have enough power to render maps to the quality level we take for granted in the OSM map tiles. And if you expect it to stay current, then it would need to be Internet connected 24x7 just to keep up with the planets changes and improvements. If you want to set up your own OSM-based tile server, the instructions can be found at http://switch2osm.org/ under the "Serving Tiles" tab.
I do plan to support the OSM API to fetch LOCAL raw data and render that data on an as needed basis for viewing. I haven't done it yet because I KNOW what the outcry will then be. The maps will look completely UGLY when compared to what we've all become accustomed to in our paid (Garmin) devices and (free) Internet-connected services.
I love what I see with this program, but I'm guessing that this little niggle is something that generates a fair bit of effort for some of us who want to use the app with our mobile radios, and no internet connection.
I'm glad you like the program, and I do what I can to make it useable for a broad range of users. But quite honestly, most of us a) use the program at home or b) use it mobile in a VERY localized area, or c) have a cellular data plan that allows us to access the maps we need, when we need them, (almost) wherever we are. A very small number of people use APRS RF mobile, and a very small percentage of those actually run a map-based APRS client while operating in that mode. You, my friend, are in a very, very small minority (unfortunately, IMHO). But you're asking for a lot of work to be done by someone (me) for the benefit of that very small population.
I've got a 3GB/month data plan and have not (yet) cracked 1GB of usage in any single month. But then again, that's on my PHONE, but even there I never hesitate to zoom over to anything that's interesting no matter where it is on the planet.
But when I'm planning a trip, I do just what was recommended to you. I put together a MultiLine object (same effect as a GPX file) and tell APRSISCE/32 to "drive" that route at several zoom levels. The biggest problem I have with that is that you also need to make sure your machine's screen saver doesn't kick in because the maps are only fetched if Windows asks them to actually be displayed on the screen, a truly less-than-optimal solution, I agree.
But until I have the time to invest in attempting to locally render maps that I consider to be even close to the OSM pre-rendered standard, we have to live with what we've got. And while living with what we've got, we need to make sure we don't upset the OSM Tile Server Gods by ripping too many maps for too large an area at too many zoom levels in too short a time.
They DO monitor their tile servers and CAN identify the applications that are pulling down their tiles. A while back, they actually contacted me because APRSISCE/32 was in the top 10 tile consumers from their tile servers. I carefully explained the situation, especially the fact that they added a clause to their Tile Server Usage policy AFTER I had released my application. They subsequently explained that I could rest easy, but I know that it would be trivial for them to throw one switch and all that any of us would then get for our map background would be:
So, for your trip across Canada, I'd encourage you to make sure your Garmin or other commercial automotive GPS has up-to-date maps and set up a GPX file of your planned route and "drive" it at zoom 12 or so and live with the maps that you then have available. Oh, and remember to turn off the Tile Purger! Or, and I don't believe I'm even suggesting this, switch to UI-View and pop the $$$ for a copy of Precision Mapping which, AFAIK, is the ONLY commercial mapping application to allow third-party applications to access their mapping database.
Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
PS. You can also read http://wiki.openstreetmap.org/wiki/Blocked and follow their instructions for an alternate map source, but you'll notice that Windows isn't one of the platforms for which they provide alternatives! We're in this together, so please don't get too carried away pulling down the maps that you "might" need or we all might find ourselves driving around without maps.
- Hi Ron,
> I had already PAN>ZOOM>PREFETCHED, at least locally, fairly heavily. Howmuch the DRIVE OVERLAY was doing was not obvious since the fetched tile
count was low. I "drove" a GPX for a road trip of 150Mi and only fetched
about 70 tiles. I had already been through there along the intended route
That is to be expected.
>I am running RF on the road, so I have the purger turned off, and I havearchived my tile files at home, so I might not need to download much for
quite a while now. I have a library of three sets that cover just about
everywhere I might go. I expect my overall tile download is fairly low,
spread out over the past year or so, even though I am supporting 3 computers
If your systems are on the same network then all the systems can work on one
tile collection. One system could be set to purge every 20-30 days. This
way, you will get the updated tiles.
> I travel with a tablet.I normally use my tablet in my daily driver. For longer trips, I like my
netbook (Lenovo). I don't leave the netbook in the vehicle because there is
more personal stuff on it and it cost a lot more. Plus, I don't want to beat
it up more than necessary by moving it around daily. I occasionally connect
to the OBDII port and the netbook handles all the applications better.
> I think you said you were running a DT360. The bottom plate on mine runsat a measured 115F+-. That seems hot, even if it's a heat sink. How does
that track with yours?
It does get warm but I have not measured it. I don't know if you mount yours
in a mount or not, but, you may be able to add air holes in the mount and
point an AC vent towards it. Try turning down the brightness. It saves power
and should generate less heat. I have also contemplated adding a heat sink
to the back. But I haven't done much more than think about it. Something
like this is what I had in mind.
> When I "drive", rather than use my tablet, I'll take my USB drive and plugit into my desktop and start the instance from the drive.
> I don't want a flash drive sticking out of the tablet while on the road. Ibuild the GPX on my Win7 machine, then transfer it to the tablet and let the
tablet fetch while I do something else. the tablet is getting a bit crowded
on memory, I don't even keep the GPX on the tablet. 4Gig isn't as big as I
thought it would be <G>
I assume you don't want it sticking out to avoid possibly breaking
something. I understand. There is a lot of potential for breakage. This is a
I already have a power supply connected requiring careful handling. So, I
plugged in a USB hub. Connected to the hub; GPS, USB stick and an OT3. I
keep looking at the IOGear keyboard. It has a trackball included. It will
require a USB device (similar in size to the memory above) plugged into the
tablet. I'll add it to the hub.
I took apart the tablet's desktop base. I hope to mount it on a Ram mount or
another solution. All the connections will go to the base rather than the
tablet. This will save wear and tear on the connections in the tablet when I
do move it around.
Currently, I use a mobile desk in my '00 Toyota Corolla. It isn't a bad
solution but I want the tablet up out of the way of my coffee mug. Plus, it
does impact the passenger a bit. She doesn't mind it there but I would
prefer to move it. I have the laptop version so it is wider and taller than
my netbook. With either the tablet or netbook, the cables are protected by
the edge of the tray.
It wasn't working 7/1 @ 9:40 EDT, so try:
This should give you some food for thought! :)