Trig TN70A GPS Receiver

ADS-B OUT

ADS-B OUT AND ADS-B IN
This illustrates aircraft operating within a full ADS-B environment. Note that ground services are only available in the U.S. (these include weather and traffic services).

ADS-B uses a Trig transponder, typically combined with a GPS, to transmit highly accurate positional is information to ground controllers and also directly to other aircraft. This transmission is known as ADS-B Out and its accuracy is greater than using conventional radar surveillance. This gives air traffic controllers the potential to reduce the required separation distance between aircraft that are ADS-B equipped.

ADS-B is seen as being vital to maintaining future efficient airspace management in busy airspace. It also provides advantages in remote ‘non radar’ areas too – here suitably equipped aircraft, with a traffic receiver connected to a display can see other aircraft without conventional radar coverage. This enhances aircraft visibility and reduces the risk of air to air collision.

ADS-B uses satellite and transponder technology to provide the following benefits in an ADS-B environment:

More aircraft can operate safely in the same airspace, so congestion is reduced.
ADS-B technology enables more direct aircraft routing – this can generate significant time and fuel savings.
With appropriate equipment it’s possible to have a live ‘traffic picture’ in the cockpit.
ADS-B enhances flight safety and collision avoidance.
Aircraft with ADS-B Out provide air traffic controllers with ‘pin point’ positional and flight information data. Trig supports 1090ES, the ICAO international standard for ADS-B that can be used throughout the world.

• EASA Form One
• TA70 certified Antenna
• Installation kit:

  Connector, coaxial TNC straight (1) 00723-00

  Connector, coaxial TNC right angle (1) 01383-00

  Headshell, 25 way (1) 00726-00

  25 way D-type, Female (1) 00866-00

  Crimp Terminal, Female, 22-24 AWG (14) 00730-00

Experimental Glider

Certified Glider

What else will I need to be ADS-B compliant?
The TN70 certified GPS reciever provides a compliant position source for your ADS-B Out system. A Trig transponder will also be required – this acts as the hub of your ADS-B Out solution transmitting data to ground stations and other aircraft (which are ADS-B equipped). In the U.S. FAA FAR 91.227 requires your installation to be capable of identifying the correct phase of flight – this demands some means of Air-Ground determination. Our STC provides a simple means to meet the regulations using the latest transponder software with automatic air ground, this removes the need for a squat switch or air ground switch.

What certification does the TN70 hold?
The TN70 has FAA TSO certification, in most regions the TN70 will require an installation STC. Check our STC section for the latest approvals.

What are the key benefits of an aviation GPS source like the TN70 or TN72 compared to a consumer GPS receiver?
With good satellite coverage, both will give an accurate position fix – they use the same technology and the same GPS satellite sources. The big difference is how they behave when coverage is poor or lost. A consumer GPS will estimate a position and trajectory for some time after losing satellite data. That gives the user apparent continuity when driving under bridges, or walking past tall buildings, but that behaviour is not suitable for safety critical applications, especially in a dynamic 3d environment like an aircraft. An aviation GPS will perform fault detection and exclusion to remove poor satellite data from any position solution, and will report loss of position integrity or loss of position very quickly. That appears to users that the aviation GPS is “worse” than the consumer GPS, since it gives up reporting a position when the consumer GPS keeps running. That is a deliberate safety design decision.

Why does my certified GPS take longer to find a position fix than my uncertified handheld device when I switch them both on?
Once it has locked on to the satellite transmissions, any GPS receiver needs data on the position of the satellites – called ephemeris data – to calculate the receiver position. Each satellite transmits its own data every 30 seconds. It takes 18 seconds to send the ephemeris data and the other 12 seconds in the cycle contains data about the rest of the satellite constellation. Depending on where in the 30 second cycle the satellites were when the receiver was switched on, it could take between 18 and 30 seconds to acquire the ephemeris data. The downlinked data has parity bits for error detection, but does not support error correction or higher integrity checks. For a safety of life application like aviation, the solution is that a certified receiver must hear the same ephemeris data twice before it is allowed to use it. This means a minimum acquisition time for each satellite of 48 to 60 seconds. Total time will be longer than this taking into account system initialisation, interference, and other environmental factors, but a fix after a minute or so is normal. So how does an uncertified GPS beat that? The first speed gain is simple – consumer GPS doesn’t wait for the second copy of the ephemeris data, it simply believes what it was told the first time. As a result, it can have a position fix in between 18 and 30 seconds. But an even quicker solution is available to a GPS built into a phone or anything else with a data link – instead of waiting for the ephemeris data to be transmitted slowly from the satellite, it fetches the same data from an online server. With a good data connection like a 3G phone, it might take only 1 or 2 seconds to receive all the ephemeris data over the line, and then a GPS position can be determined in less than 5 seconds.

How heavy is the TN70?
The TN70 is light weight unit – the hardware box weighs 1.06 lbs and the antenna weighs 0.31lbs.

Can I buy the TN70 without the antenna?
The TN70 comes with an antenna as a bundled kit, optimised for the best results. We do not sell the TN70 as a stand alone unit.

When I purchase a TN70 what comes in the box?
The TN70 kit comes with WAAS GPS hardware unit, matching WAAS antenna and installation kit. The TN70 installation instructions are online only.

In the U.S. if I want to fly in 2020 rule ADS-B airspace in an LSA, experimental or home built do I need a TN70?
Light-sport, experimental and homebuilt aircraft can all use the TN72. With a Trig TT31 or TT22 transponder, this meets the GPS Position Source requirements of FAR.91.227 and is 2020 compliant.

Certified Glider

• Trig TT22 Class 1 Transponder
• TT22 Cable Harness
• TN70 Cable Harness
• Transponder Antenna (Must be certified)
• RG400 Coax Cable
• Circuit Breaker
• BNC Male Crimp
• ADS-B System Airspeed Switch Kit