AUTOMATIC DEPENDENT SURVEILLANCE BROADCAST (ADS-B) OR ... "ACTIVE" TRAFFIC
There's a lot of talk about ADS-B but ... consider these arguments for adding Active Traffic NOW!

From Bob Hart   Senior Avionics Consultant/ Marketing Manager  APG Eastern Avionics
                                                                                                     
     The 2020 mandate for ADS-B is about 8 years away, during which time there will be varying degrees of mixed equipage, but essentially everyone will still be required to carry a transponder.  The fact is there are significant limitations with ADS-B that make having an active-surveillance system critical to flight safety both now and in the future.
 
      Here are some of the considerations that make "Active" Traffic the right choice for anyone serious about Traffic Avoidance and Safety (and who isn't?):

1)      Portable ADS-B units receive limited or no Traffic info. Some portable systems were designed to see other nearby aircraft that are sending an ADS-B Out signal, but currently there are simply not very many aircraft equipped for ADS-B Out.  Since these portables do not send an ADS-B Out signal, the only way they can receive TIS-B traffic broadcasts from the ground is if they happen to be flying near an ADS-B Out equipped aircraft and they can eavesdrop on their signal.  TAS interrogates and displays all nearby Transponder-equipped aircraft.

2)      Limited Ground Station Coverage through 2014
While the East and West coasts have ADS-B-based ground stations in place, full US coverage is not expected until late 2014. Even with dual-band ADS-B products that may be coming out later this year, if you fly in areas without ADS-B ground infrastructure, you will not be able to see all the traffic.  TAS does not rely on ground stations.

3)      Limitations due to signal Line of Sight  - At lower altitudes and especially in the pattern at many smaller G.A. airports, you may be below radar coverage and below ADS-B coverage, and thus not be able to receive ADS-R and TIS-B traffic.  TAS works at any altitude.
 
4)      ADS-B is dependent of GPS - An on-board GPS failure could cause you to lose your ADS-B and thus you would be without traffic awareness.  During periods of poor satellite geometry or solar storms, ADS-B accuracy may be degraded or lost.  TAS works independent of GPS.

5)      978MHz solutions do not work outside US. - It's important to keep in mind that if you fly to Canada or Bermuda or other regions of the world, the only ADS-B available is via 1090MHz and there are no mandates to equip for most aircraft flying below the flight levels.  TAS works anywhere in the world.

There is great promise for ADS-B, but it has some limitations as a traffic detection safety system, especially during this critical mixed-equipage period.

     The importance of having an active-surveillance Traffic Advisory System cannot be overstated.   The key to safety with any traffic system is its ability to see and display all nearby aircraft.

Need more info about your "Active Traffic" options?
Go to ...
http://www.apgavionics.com/product_info … tems-p-638

This info courtesy of the nice folks at Avidyne Corporation

Wanna "Talk" about it?   Bob Hart   APG Eastern Avionics  This e-mail address is being protected from spambots. You need JavaScript enabled to view it    www.avionix.com