Hi. On 29.01.2016, at 11:47, Dmitry Zaharov <[email protected]> wrote: > Recently, I've started stumbling data for MLS. > (Looks like I'm the only app-powered stumbler here in Riga, Latvia)
Welcome on board :) > So, first of all, what's the meaning of the following Mozilla Stumbler > screenshot? > See - http://is.gd/vKKx79 The symbols you get should be explained in the legend in the app drawer. You can open it, if you click on the stumbler icon in the top-left corner or swipe in from the left. In the lower part of that drawer is a section called "Map Legend". You always get a colorful icon at each of the places we collected a report. A report is the combination of a GPS reference position and multiple cell or WiFi networks observed at that position. A green circle signifies that we could collect a GPS position, one or more WiFi networks and one or more cell networks. A purple circle means there was no cell network and a blue square means there were no WiFi networks. >From each of these icons we then draw a line to a red circle (if the "Show MLS >locations" option is enabled). The app takes the data collected at each point >and queries MLS to get its best estimate of where you are given the data at >that position. If things go well, the red dot is very close by the report >icon. This happens for some of the data points in your screenshot, so we >definitely have data in the area. > Does it mean MLS has absolutely NO data for this region?! > The actual coordinates was the following: > https://www.google.com/maps/place/56%C2%B056'33.3%22N+24%C2%B006'45.4%22E/@56.942571,24.110408,17z/data=!3m1!4b1!4m2!3m1!1s0x0:0x0 > > Actually, I was here 2-3 days ago, and still the MLS coordinates are > missing for this place. > (all the grey lines lead us to the default point in the center of the city) MLS will try to find a position based on WiFi networks, falling back to cell networks, back to larger cell areas and finally GeoIP. If there isn't any or not enough information available for some position, you end up with all the lines going to one central place. This could be the center of a cell network, the center of a much larger cell area or a city center or even region center via a GeoIP estimate. > So, the question is - how fast my just stumbled coordinates (via Android > Mozilla Stumbler app ) > will be used by MLS to determine the particular device location? MLS will process the data most of the time in a couple minutes after the upload has finished. If we are in the middle of software updates, we may halt data processing for a while and it could take a couple hours for data to be processed. We've optimize the data processing for general throughput via various sorts of batch processing tasks, rather than optimizing it for low latency (from upload to finish). Most of the data we get is from clients that don't have any UI, so there's no visual feedback back to them. Unfortunately this currently means that the Mozilla Stumbler app tends to upload data and then does all the queries to check the offsets, before the uploaded data has been processed. So the visual feedback you get isn't actually based on the data you just collected, but on everything that has been uploaded before. We wrote the stumbler visualization feature while data processing was still almost instantaneous, so this wasn't a problem a year ago. Right now I fear the feature is a bit misleading to useless. Hanno _______________________________________________ dev-geolocation mailing list [email protected] https://lists.mozilla.org/listinfo/dev-geolocation
