下面是被转发的邮件：
> 发件人: Maxthon Chan <[email protected]> > 主题: 回复： CoreLocation clone > 日期: 2013年6月4日 GMT+0800上午9时07分39秒 > 收件人: Ivan Vučica <[email protected]> > > Agree on most of that, but one problem about tiles: can we do that ourselves, > distributed, use Display PostScript (probably backed up by Cairo or > Ghostscript) and/or Quartz (on OS X)? Just pull raw vector information from > OSM directly (a lot smaller than tiles!) and lay it out directly, locally? > > About OBM, I think the mathematical formulae behind the triangulation cannot > be patented, public thesis may be be able to be found, and both GNU MPFR and > clang big integer extension can handle the calculation pretty well. Thus we > can: > 1) if OBM have the API to query their database for a small list of BSSIDs, > let every device calculate its own location based on what OBM have, or > 2) if not, set up a server that periodically pull updates from OBM, and > calculate user location based on a list of BSSIDs and signal strengths from > the user. > > I checked again, the board I used to run Android came with a Broadcom > communication chip that *have* GPS capabilities. (strangely, not 3G) > > And about the 3G dongles, That would be tricky, indeed. But can we spin off a > subproject that develops 3G dongles as open hardware (like Raspberry Pi and > Arduino) and supporting all those AT commands which is most consistent to > some standard? If we have that project, I would certainly buy one of those > dongles. Or we can start off with common, unlocked (as in, not limited to a > certain carrier) dongles. > > 在 2013-6-4，上午8:45，Ivan Vučica <[email protected]> 写道： > >> >> On 4. 6. 2013., at 01:02, Maxthon Chan <[email protected]> wrote: >> >>> From what I know, you can use Android location services without Google Maps >>> app as tried on a home-brew Android device - this meant that probably the >>> locating API is not in the Google Maps app but in the system itself, and >>> can be safely extracted. >> >> Indeed? What backend does that use? :-) >> >> If the homebrew device has GPS on it, then the location API's functionality >> does not surprise me. If it, however, does not, then listening to traffic >> with Wireshark is in order to figure out whose terms of use you want to >> study before reversing the protocol :-) >> >> From what I can tell, you can't actually check this on a retail device which >> comes with Google services, because these services can also provide >> information to the "android.location" API, not just the "Google Location >> Services for Android": >> http://developer.android.com/guide/topics/location/index.html >> >> If it turns out it is based on WLAN stations, it still almost certainly uses >> an API endpoint that comes with terms of service. And if it's Google Maps >> Location API, then all I can say is -- just because a blind eye is turned >> when a Google-backed open source project (that is, the "Android Open Source >> Project" as it's called) uses the API - well, that doesn't mean they'll like >> GNUstep using it. >> >>> For OpenStreepMap and OpenBmap, this would require a cooperation between >>> projects - they should be willing to back up our CoreLocation and MapKit >>> implementation. >> >> Yes. From what little I know about OSM, it's primarily a data source; so we >> would also need someone to provide tiles (the rendered images themselves). >> An iOS app I know offers a choice between about 8 different tiling >> providers; it may be worth looking into that. >> >> By the way -- I've just remembered MySTEP also has a MapKit implementation >> which happens to use OpenStreetMap: >> http://projects.goldelico.com/p/mySTEP/page/MapKit/ >> >> Now, OpenBmap. OpenBmap doesn't actually provide a complete service; it >> primarily provides a database of MAC-to-geolocation mappings. This is great >> for what is needed for Core Location; one just needs to develop a good >> triangulation algorithm based on relative signal strengths of multiple MACs. >> Upload a list of MACs and signal strengths, get back the geolocation. :-) >> >>> Have you ever noticed that there are lots of 3G network adapters for >>> computers that plugs onto a computers USB or ExpressCard port? For some >>> computer models (like Dell Latitude D620, as I have a really old one still >>> alive, kicking and serves my blog - shameless plug, >>> http://blog.maxchan.info/ - to everyone over the Internet) there are even >>> built-in ones? >> >> Sure. Can you issue an AT command that will list all the cell tower >> identifiers along with signal strength toward that particular tower? Can you >> issue an AT command to get an identifier of just the tower you're connected >> to, so you can combine that with the current connection signal strength? :-) >> >> That's the problem: you may be able to find the AT command on a particular >> dongle, but it's bound to be nonstandard and probably won't exist on >> whatever garbage operators around the world tend to sell. (For example, I >> had some... 'experience' with a dongle that came with OS X 10.5 drivers. >> These included libcurl... which, when overwritten on 10.6, broke >> loginwindow.app. Not a nice situation to be in. Even worse is spending a few >> hours on diagnosing that this is, indeed, the problem. *sigh*) >> >>> The MapKit for OS X in question seemed used only public Google Maps API. It >>> is freely licensed as well, no key required and the author himself is not >>> in trouble as well. >> >> Did you read Google Maps API terms of service and, more importantly, the >> billing information? Aside from decision to go "thermonuclear", financials >> are considered one of the reasons why Apple opted for rolling the infamous >> Apple Maps service. >> >> Regarding the author of MapKit for OS X being sued: just because a tiger >> turns a blind eye doesn't mean you should go poking him with a stick :-) >> >> Plus, aside from Google Maps API, you need to consider Google Maps Location >> API, which has no free tier apart from 100 requests a day. Hardly enough for >> any serious use. >> >> On 4. 6. 2013., at 01:07, Maxthon Chan <[email protected]> wrote: >> >>> And by what I say as crowd-sourcing, I mean ask users that are willing to >>> share for information. What we are asking for here is several numbers: AP >>> BSSID, transmission power, and its geological location (latitude and >>> longitude, as well as height). The request is done by the device uploading >>> a list of BSSIDs received and its signal strength, hence BSSID never leaves >>> our servers, and thus privacy issue avoided. >> >> >> Sure; so the only people violating the privacy are -- we ourselves? :) >> >> Plus, what happens when someone queries for location of MAC "XYZ"? We reveal >> the location -- which is the purpose of the API. Sure, that happens already: >> Google's doing it, Apple's doing it, Skyhook's doing it, OpenBmap people >> seem to be doing it. I'm just saying that it's private information, in a >> way. :-) >> >> from the things-we-unknowningly-reveal dept: >> >> I really liked it when, at my former workplace, we received a crash report >> for a game on OS X. Something ticked my curiosity and I playfully passed >> into Skyhook the several listed AP MAC addresses that OS X dutifully >> included in "full system report". Imagine my surprise when it turned out >> that Skyhook claimed the location was just across Apple's campus... >> >> ...and yes, it did turn out it was a crash report from an Apple employee. >> >> -- >> Ivan Vučica >> [email protected] - http://ivan.vucica.net/ >> >
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