All data from TTNmapper.org should be considered under the PDDL v 1.0 license (http://opendatacommons.org/licenses/pddl/1.0/).
We use SF7. This provides us with a map of "worst case" coverage. It also does not make sense to use a higher SF, as the performance decreases when you are mobile. The time between packets, and therefore distance between samples also increases with higher SF. SF7 is just good enough.
Possibly the gateway that received your packets does not send its coordinates in its status update packets. If you know the gateway owner, please ask them to enable the GPS (and fake gps) so that the coordinates are sent through. If this is the reason for your measurements not showing, you can check under Advanced Maps, enter your node address, and view the map. If you now see circles without lines connecting them to a gateway, this issue is confirmed.
Did you mark your data as experimental? If so, the data will not show on the main map, but on a separate map containing only your experiment. Please disable experimental mode in the app so that you can contribute to the global map of TTN coverage.
The maps should show new data within a couple of minutes. A scheduled task starts executing every two minutes to aggregate data and create the GEOJSON files. The task may however take a long time to execute.
If this is not the case, likely the Android app is not uploading data to our server. It is also possible that the server is down (but then the website won't display), or that for some other reason stuff are breaking on our side. Best to log your coverage to a file and e-mail it to us if your results are not displayed within a day or two. When we get an email like this, it will also be seen as a bug report and the issue will be investigated.
As I'm typing this it has not been implemented yet (feature implemented on 2016-03-20), but the idea is to hide all "old" measurements for a gateway if it has moved more than 100m. Therefore, if you mapped the coverage of a gateway, the measurements showed up on the map, but the gateway was then placed at a new location more than 100m from the original location, the old measurements will be hidden.
The major reason for this is that the map should be an indication of the current TTN coverage, not what it was a few weeks ago. Also, if a gateway moves, the origin of the radial lines will move too. It is possible to have multiple markers for a gateway, creating in essence two separate coverage maps, but again, the old coverage does not mean anything to us.
To be safe, e-mail me your log file (if you also logged to a file).
It is possible that some datapoints did not upload correctly to our server because your internet connection did not work correctly, however this is unlikely.
The most likely reason is that the gateway that received your packets does not report its location. We therefore are not able to plot the datapoints as we also do not know the path the packet was received along.
We aggregate datapoints accross a region of 0.005 degrees to make displaying it on a map faster. Click on a gateway and choose to view only that one's coverage, and you will see data aggregated over a 0.0005 degrees area, thus more data points.
All data is dumped into tab-delimited files at an irregular interval. The dumps are available at http://ttnmapper.org/dumps. If you want newer data than what there are dumps of, please contact me.
No public api access is given to the database. This is due to the amount of data and number of possible queries that won't be possible to handle on the server. Please use the dumps and your own database.
The GEOJSON files used to draw the TTNmapper maps are also publicly available at http://ttnmapper.org/geojson.
If you change your gateway's location to another one more than 100m away, any old measurements for your gateway will be hidden automatically.
In any other circumstance, contact me.