Sometimes app Explane says ‘No airplane captured’ after you tried to measure the sound level of a passing aircraft.
This is not an error, but a built-in feature: the app checks if it has all data necessary to make a registration. If not, it says ‘No airplane captured’.
The app needs several data for its registrations. It needs to get the airplane data from the Open Sky Network, it needs a location, a working internet-connection and it needs access to your microphone to be able to measure.
If one of these resources is not available or if it takes to long to connect to the database, the app always says ‘No airplane captured’. It might have been able to measure noise levels, but maybe it couldn’t get fast enough to the airplane-database. Or is (temporarily) not able to access internet.
The database of current aircraft positions is filled with data from ground stations that collect the transponder transmissions. Most of those stations are operated by private persons who can also have problems with their internet-connection or are updating their devices. The latest data that Explane receives can then be ‘too old’ to be used.
In all of these cases Explane will not register your measurement. You can try again to ‘catch’ following airplanes. If the app shows the warning again and again, you better wait for an hour or so to try again.