Update README with FlightAware-specific info.

README.md

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+Dump1090 MR README
+===
+
+Dump1090 MR is a FlightAware fork of Malcolm Robb's fork of
+Salvatore Sanfilippo's dump1090 program.  FlightAware uses it as an
+important element of PiAware (https://adsb/piaware/), a Debian package
+for forwarding ADS-B data to FlightAware.
+
+Salvatore also invented an extremely popular in-memory database called redis,
+among other things, and he's pretty busy and doesn't have a lot of time to 
+jack with dump1090.
+
+Malcolm split out dump1090's source code out into several different files 
+and has done steady work maintaining and updgrading it.  People have been
+sending him patches in the form of pull requests and he's been assiduously
+bringing them into the mainline code.
+
+Although dump1090 is presented primarily as an ADS-B (Mode S) decoder
+specifically designed for these little RTLSDR USB dongles that contain
+a software defined radio and FPGA and were originally intended for decoding 
+certain satellite TV broadcasts, dump1090 can do many other useful things
+such as 
+* decode and interpret ADS-B messages from various formats
+* Stream ADS-B messages in various formats using Internet-standard TCP sockets
+* provide a web interface to show aircraft traffic on a map in real time
+* and more
+
+Since airborne aircraft transmit their positions twice each second, ADS-B
+receivers located in high traffic areas can receive as many as thousands
+of messages each second.  
+
+Much of this information can be filtered out without a significant loss
+of fidelity at the receiving end.  For example, an aircraft flying at
+a high altitude with a consistent heading and speed, the aircraft's
+location information can be forwarded less frequently.  
+
+Also aircraft equipped with legacy transponders, as most still are, only
+their altitude is being transmitted, not their latitude and longitude, etc,
+and as these messages aren't as useful they don't need to be sent as often.
+
+The FlightAware fork leverages dump1090 to create a new message format
+that is filtered as described above plus with additional criteria
+and then we group multiple messages together into a single TCP packet
+to reduce overhead (as each IPv4 packet has a 64-byte header),
+ultimately requiring a small fraction of the bandwidth used by the other
+data formats dump1090 can send natively.  This is on port 10001 by default.
+
+Within the dump1090 repo also is a program called faup1090.  When someone
+is running their own dump1090 or native Malcolm Robb dump1090, faup1090
+can connect to dump1090, interpret the packets it receives, and translate
+them into the same filtered format our fork of dump1090 produces.
+
+FlightAware's PiAware Debian package (https://flightaware.com/adsb/piaware/) leverages either faup1090 or dump1090
+with additional software to connect to FlightAware with a compressed,
+encrypted TLS connection, log in using your FlightAware account and
+password, and forward your ADS-B data, where it is collected as part of
+FlightAware's worldwide network of Airspace National Service Providers,
+satellite tracking providers, networks of ADS-B providers, our FA-managed
+ADS-B network.  
+
+By contributing your ADS-B data to FlightAware you
+* contribute to the accuracy of FlightAware's flight tracking, almost all of which is available for free worldwide through the FA website in 15 languages
+* gain the ability to see a realtime picture of all ADS-B traffic FlightAware knows about
+* make the Internet itself more useful
+* help people communicate and share information
+
+Every day hundreds of thousands of people save time and energy using 
+FlightAware.  If someone leaves for the airport an hour later because the
+flight they're meeting is an hour late, they got an hour of their life
+back, and that's an hour not spent in their car with the engine running
+or whatever.  It's a win for the person, a win for the environment, and
+your contribution to that is real and genuine.
+
+While doing this, FlightAware in no way restricts your ability to share your 
+ADS-B data with other flight trackers.
+
+Most people will have no need to grab dump1090/faup1090 from source code and 
+build it.  If you already have dump1090 running with some sort of ADS-B
+receiver, all you need to send stuff to FlightAware is to install our
+Debian package and configure it with your user name and password.
+
+But for the intrepid, here is the source code, in all its glory, freely
+redistributable under the permissive Berkeley copyright, modifiable for
+your use and others, including for profit, should you desire.
+
+We will continue to track the Malcolm Robb fork of dump1090 for the
+foreseeable future and maintain our modifications.  We solicit any bug
+reports and bug fixes are, as always, for the same.
+
+
 Dump1090 README
 ===