Been enjoying the series on Hak5 - I found out about dump1090 by reading this topic.
I found a fork of dump1090 that I like better than the original.
Software: git clone git://github.com/MalcolmRobb/dump1090.git
Instructions for compiling are the same as for the original in the first post.
Once this is compiled and running, edit config.js in the public_html folder and enter your location for map settings and site settings. Set SiteShow=true and it will show you how far away the plane is. I'm seeing about 75-100 nautical miles out with my indoor setup.
If you select a plane, this also draws a line on the map showing the track.
This program also shows a signal column in the interactive mode, so you can get a relative idea of the signal strength when you switch antennas.
I recommend that you fire up gqrx and locate a station at a known frequency - the local NWS station on 162.xxx mhz is a good candidate. Then set the frequency to match exactly. If the station is centered in gqrx - then no further adjustment is needed. If the station is not in the center, adjust the frequency correction in the input controls until the station is coming in on the right frequency. In my case, I had to set it to 65 to make the frequency display accurate.
Take the value from gqrx and feed it into the --ppm argument for dump1090. I find that this makes a noticeable difference in the number of planes detected.
I've tested a lot of command line options. The current command line I am using is:
./dump1090 --enable-agc --aggressive --interactive --interactive-ttl 300 --net --net-http-port 8080 --ppm 65 --modeac
This turns on both the interactive window and the maps at localhost:8080. It also sets the timeout for the interactive mode to 5 minutes. The maps have a different timeout, so the planes disappear on the map about a minute after loss of signal.
You can also see interesting stuff if you open another terminal and
telnet localhost 30002
or
telnet localhost 30003
