MBTiles and external drives

Guy S's Avatar

Guy S

30 May, 2016 07:56 PM

Hello Matt,

Have you given any thought to selling large MBTile map atlas that can be stored on phones or tablets for off-line use? Something with regional or state coverage? Tricky I know but I bet there is a market given increased memory cards and external storage of devices.


  1. Support Staff 1 Posted by matt on 01 Jun, 2016 05:52 AM

    matt's Avatar

    I've thought about it; I'm already producing some MBTiles files with wide-area coverage for offline use for SAR. Semi-custom, transferred via thumbdrive, not exactly easy to flip a switch and offer them up for download.

    For technical reasons, I have to assemble the entire .mbtiles file in advance rather than streaming it as I build it like I can with zip files. Because of this, you can already notice that the small-area downloads are faster when "printing" a KMZ than an MBTiles file. So I'd probably have to just pre-generate files that match a grid, and offer them up for download.

    Is anyone doing this now? Is there anything you can point me to that would give me a sense of what the market looks like, or what pricing is reasonable (I have no idea)? There are enough high-priority items with the site that I'm wary of chasing side projects like this unless I'm confident that they'll pan out.

  2. 2 Posted by Guy S on 01 Jun, 2016 02:59 PM

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    Thank you for your reply. As far as I can tell, no one is doing this. I've searched and couldn't find a good enough solution. If I did, I would jump on it. The only demand I know for sure is mutual friends who all have phones or tablets that have replaced their GPS units entirely. But there is demand in the overland community too.

    As you know, tablets have become dedicated mapping units and have large amounts of storage either onboard, external card or via USB. We are covering large areas that are difficult or nearly impossible to download manually ahead of time. Not to mention the different layers involved. Mobile Atlas Creator used to be a good resource to create large off-line maps but now the map selection is limited. It is not useful anymore.

    The current solution I'm using involves Backcountry Navigator and OpenAndroMaps. It is ok but lacking. Your Caltopo maps are better.

    This idea might be best suited for an app though. Something I'm sure you've already thought about.

    Thanks for your time,


  3. Support Staff 3 Posted by matt on 02 Jun, 2016 02:49 PM

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    Thanks. Since BCN licenses my map layers, I guess the final question I'm unclear on is whether this would need to be a drive/SD card I'd ship to people to keep them from download 10s of GBs, or whether it just needs to be a pre-packed download service to get around in-app limits.

  4. 4 Posted by Guy S on 02 Jun, 2016 05:55 PM

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    Good question. Hard to say I guess. How much data would a MapBuilder Topo for a whole state (or region) take up? Gigs and gigs I assume. Could that be done as a map atlas to download or be better as a stand alone app where you could have multiple regions/states?
    Downloading a map atlas ahead of time is ok if the area is big enough, like for a whole region or state. (like the BCN + OpenAndroMaps solution) I guess some of this depends on just how much data we are talking about. Feel free to email me anytime.

  5. 5 Posted by Nancy Jocoy on 07 Jun, 2016 11:28 AM

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    I am new to t his forum but that is a concern of mine (offline use) and Maptech is so restrictive and expensive they are no longer meeting my needs...but offline maps are the single reason we still have TNP. Slowly the areas with no internet coverage are decreasing though we still have areas where you are lucky to get a text out.

    Both Basecamp and Topofusion have options for downloading and holding aerials offline on on the platform which downloaded it, but I would love to see this done as a file so that someone could download before they leave home and transfer to the base PCs. In topofusion, you just selected the area and the layers you wanted to download if I recall and it is stored in a cache. Of course that would mean being able to use the program offline as well.

     I intend to keep Basecamp right now as a GPS editor because it stores time data which is not retained in the saved track of older GPS units (like the 60cx) and our team cannot afford to run out and replace those and the old Astros. We have used the time data and the track animations to extract useful info about dog behavior. Since we also take the tracklog, not the saved track, our mapping folks do editing, based on correlating timestamps with radio log and interview with the searcher.

  6. 6 Posted by adamg32 on 02 Jul, 2016 05:13 PM

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    Guy and Nancy,

    Matt is on some well-deserved R and R, so I'll step in (sorry for the delay) and answer what I can. The state of CA, for example, requires a couple hundred GB last I checked, although that was for all of the layer options.

    An offline solution is a very real need for a lot of people, SAR teams included. I'll point you to this collection of posts: http://caltopo.blogspot.com/search?q=offline as a possible temporary fix, but there is still some work to be done before providing a truly offline solution on a larger scale which doesn't include a large satellite dish and $$$ worth of satellite internet data.

  7. adamg32 closed this discussion on 02 Jul, 2016 05:13 PM.

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