I recently acquired an AirNav RadarBox from Larry Price, W4RA and immediately found it to be a terrific addition to my monitoring station. The RadarBox is a receiver for 1090 MHz ADS-B transmissions from aircraft; it is attached to a computer with a USB cable and uses software to decode the information in the transmissions. ADS-B, which stands for Automatic Dependent Surveillance-Broadcast, consists of signals transmitted on 1090 MHz which includes aircraft identification data as well as altitude, heading, speed, and distance information which is used by the air traffic control system to help track flights. The RadarBox receives these signals and the software decodes them, listing the aircraft heard and when position information is available, plots them on a map similar to what an air traffic controller might see.
Currently, not all aircraft are equipped with ADS-B equipment but the FAA will require the majority of aircraft operating in the United States to to have some sort of ADS-B capability by 2020. Many airliners are equipped with ADS-B equipment, but not all are transmitting position and heading information. As time goes on, more civilian and commercial flights will be transmitting position and heading information in addition to identification information. Many military aircraft are also ADS-B equipped, but they don’t transmit position and heading information for security reasons.
The Radar Box consists of the receiver, an antenna and supplied metal ground-plane disc, and software. The receiver connects to your computer via a USB cable (mini-USB connector on the receiver side). In addition to the data and control, the USB port also provides power to the receiver so there isn’t a wall wart or power supply to worry about. The antenna is normally placed as high as possible on the metal ground-plane disc (near a window if inside) but I found that the steel window frame by my radio desk works much better than the disc!
So, of what use is the ADS-B receiver to the scanning and aviation enthusiast? For starters, it’s fun to watch the flights that are transmitting position and heading information fly by on the map screen. You can see routing information and follow their track along the map as well as on a vertical display that shows their altitude. ADS-B also helps identify aircraft that you’re hearing on conventional voice radio. For example, these are the military or government aircraft that my RadarBox received on 16 March 2011:
ADFD03 – T-1A, 95-0055, USAF
ADFD08 – T-1A, 95-0060, USAF
ADFCFA – T-1A, 95-0046, USAF
ADFD7B – C-26B, 91-0511, US Army
AE012E – C-9, 73-1683, USAF
*AE0160 – KC-315R, 57-1479, USAF, DECEE 96
AE0197 – C-21A, 84-0137, USAF, JOSA 313
AE05E7 – C-130H, 88-4405, USAF, PACRR 32
*AE07E0 – C-17, 94-0066, USAF, RCH 252
AE08B2 – T-6A, USAF 00-3597
AE08B3 – T-6A, USN, 165958
AE08B5 – T-6A, USN 165960
AE08BD – T-6A, USN, 165968
*AE10C1 – C-37A, USCG, COAST GUARD 101
AE10C4 – T-38G, 158844
*AE10DF – RC-12X, US Army, 92-13120, SUNNY 68
*AE10E5 – RC-12P, US Army, 93-0700, SUNNY 84
AE113E – T-6A, USN, 165972
AE113F – T-6A, USN, 165973
AE1140 – T-6A, USN, 165974
AE115A – T-6A, USN, 166000
*AE12A0 – AC-130U, 90-0163, USAF, SPOKY 44
*AE1491 – E-8C, 95-0121, USAF, PEACH 81
AE4AF4 – C-130J, 08-3179, USAF, HAZRD 65
C065ED – Pilatus PC-12/47E, C-GMPO, Royal Canadian Mounted Police
C2B1B1 – CP-140, 140102, RCAF
The software displayed the Mode-S identifier, aircraft type, serial number, service operating the aircraft, and callsign/flight ID. Aircraft with an asterisk are aircraft that I also heard on VHF/UHF (note that the AC-130 was using a different voice radio callsign than what was programmed in it’s transponder).
I’m looking forward to having fun with the RadarBox. I’ve subscribed to the AirNav network to share what my RadarBox picks up with others and I’ve connected it to the live-mode-s.info database to add to their database. I’ll also post RadarBox logs here on the blog from time to time and include them in the monthly MilCom recap posts.