This would mangle messages if the first byte of a message ended up
as the last byte returned by a read() call - it would read beyond
the end of the buffer, decide the message was damaged, and then run
off into the message data looking for a new delimiter. Sometimes
that would work (only dropping one message), but sometimes it would
run into data that happened to look like a message start but
actually wasn't, and then try to interpret that, leading to completely
bogus message data being read.
Fixes#29.
Track NUCp when we compute positions.
Do speed checks when we have an updated position with the same or worse NUCp
before accepting the new position. Don't do speed checks on new postions if
they improve NUCp - assume that the new position is better.
Include NUCp in aircraft.json
Gather stats on reasons for rejecting CPR data due to range/speed check failures.
Expire old positions if we have had no updates for 60 seconds.
Closes#16, closes#17.
the message being emitted immediately.
Fix computation of reception time so it's more sensible (the block timestamp
is some time after reception of the _end_ of the block, not the start) - this
means that message-emission times are always later than message-reception
times in SBS output, which is a bit more sensible.
Use clock_gettime in preference to ftime.
This means the 1/5/15 min values may reflect a period that ended
up to 1 minute ago, but the length of the measured period is always
as expected i.e. 1/5/15 mins.
is what was previously done and it gives us better range for small signals.
Means a sqrt() call on beast output, but this shouldn't be too bad as
it's only done once per message.
since we have 8 bits spare, so there's no chance of confusing it
with an ICAO address, and we can safely use the filter table to match
future messages without also matching equivalent ICAO addresses.
Switch signalLevel back to a power measurement, don't put SNR in there.
But make it a 0.0 - 1.0 double so we're not scaling everywhere.
Adjust for the amplitude offset when calculating power.
Adapt everything else to the new scheme.
This is adapted from the FlightAware fork, with some cleanup and
modifications needed to work with the net-cleanup changes.
Inclusion of "verbatim" TSV data read from an AVR-format input
connection is not supported.
