What is ADS-B

    In this short article we'll look at what Automatic Dependent Surveillance-Broadcast (ADS-B)  is, its benefits, limitations, and specifically how it can be used with OzRunways EFB to improve your situational awareness. 

    What is ADS-B:

    ADS-B is a broadcast surveillance system which differs from traditional transponders in that they will send out continuous signals (at least once per second) into the air around them, without needing to be interrogated by another unit first. These signals are rich with information including the aircraft's: identity (callsign), precise GPS location, altitude, and velocity. 

    How it works: 

    An aircraft transmits an ADS-B signal OUT into the air:
    Another aircraft or Air Traffic Control ground station receives this signal IN:

    This signal is then decoded and displayed as traffic on their screens (EFB, ATC station, or Avionics):
    *Portable transmissions are filtered out of  ATC displays and therefore not visible to ATC


    The Benefits of ADS-B: 

    For us pilots the benefits are simple:
    1. ADS-B signals work completely independently of the cellular network, so you don't need to rely on this network for your traffic information. 
    Relying on an external feed of ADS-B traffic (i.e. not having your own ADS-B IN Receiver) means you are still relying on the cellular network to pass this traffic information onto you. 

    2. ADS-B is a generic system compatible across EFB apps and aircraft avionics, so you will see aircraft running any system or even still flying around with paper charts!

    The Limitations of ADS-B:

    As great as it is, no system is perfect. ADS-B signals are line of sight, so caution should be used in mountainous areas as signals can be blocked by terrain. 
    This should be kept in mind especially if relying on an external source of ADS-B traffic and not your own ADS-B IN Receiver. Do you know where the ground receiver for that source is? Where the potential black spots are?

    Types of ADS-B Equipment:

    ADS-B equipment falls into 2 main categories, portable and installed. Portable meaning you can easily take the equipment from one aircraft to another, where as installed equipment remains with one aircraft all the time (typically a transponder or avionics screen). 

    Whether you go down the portable or installed route depends on: 
    1. The type of flying you do (VFR or IFR; certain airspace requirements)
    2. Budget
    3. Any existing aircraft equipment (for example, upgrading an already ADS-B capable transponder)

    You can also mix between portable and installed equipment. For example, the owner of an aircraft with an ADS-B OUT installed transponder may opt to purchase a portable ADS-B IN Receiver. This may be due to requiring installed ADS-B OUT equipment for operating IFR, but not having avionics screens capable of presenting ADS-B IN traffic. So instead they have purchased a portable ADS-B IN Receiver which sends traffic to their EFB app. 

    Remember: ADS-B OUT means others can see you, and ADS-B IN means you can see others. But if you only have IN or OUT, someone is missing part of the traffic picture! 

    Portable ADS-B Devices:

    A portable ADS-B device is just what it sounds like. Typically pocket sized, they are easily moved from one aircraft to another and can be charged via a USB cable either at home before your flight, or on the go with a portable power bank or via an in cockpit usb socket. There are several types of portable ADS-B, however we here at OzRunways recommend the Sentry or Sentry Plus. 

    Sentry features: 

    Dual-Band ADS-B In Receiver
    Displays traffic in OzRunways.
    Built-in GPS
    Displays your GPS position in OzRunways.
    Attitude and Heading Reference System (AHRS)
    Powers the artificial horizon in OzRunways.
    Carbon Monoxide Detector
    Warns you of dangerous CO levels in the cabin.
    Extended Battery
    12 hours of continuous operation for long flights.
    Supports Up To 5 Devices
    Allows PIC and Co-Pilot to both connect to the Sentry.

    Purchase one here!

    SkyEcho 2 features:

    Dual-Band ADS-B In and Out Receiver
    See and Be Seen by other aircraft without equipping with a traditional transponder! 
    Displays traffic and broadcasts your position over the ADS-B network.
    Extended Battery
    12 hours of continuous operation for long flights.

    Purchase one here!

    Further Information: 

    More information can be found on our knowledge base here:
    Or contact our friendly support team with any questions: support@OzRunways.com

    There's also a lot of information that goes into deeper detail about Automatic Dependent Surveillance-Broadcast (ADS-B) available from the authorities, for example here are some links to CASA's and Airservices' Australia documents:

    Published