Optimizing Your Receiver for Reliability and Performance

Checklist for Optimal Receiver Setup

✅ Power
✅ Antennas
✅ Cables
✅ Signal Amplifiers and Filters
✅ Internet Connection
✅ Lightning and Electrical Surge Protection

Analyzing your Receiver 

Which of these graphics does your PiAware or FlightFeeder’s hourly position reports most resemble?

The graphic on the top is a receiver that’s running at an optimal state. If yours looks more like the graphic on the bottom, there could be a multitude of reasons for this. Below we have provided you a few tips and tricks on how you can get your position reports looking like the graphic on top.

✅ Power

Do you have any idea how long your receiver has been running since its last boot? Check your “System Uptime” on your receiver’s Status page by entering your receiver’s IP address in a Web Browser (on the same Local Network).

Raspberry Pi's are designed to be able to run 24/7 so if your System Uptime is indicating otherwise (and you did not intentionally reboot it), you should check on your power.

• Make sure the power supply is plugged into its own dedicated power source not shared with any other devices.

• Use an official Raspberry Pi power supply.

• Use an uninterruptible power supply (UPS) if you live in an area subject to power outages.

• Set your ADS-B alerts to alert you when your receiver reboots.

Sufficient power will not only keep your Pi up and running, but also make the SDR and MLAT function properly so it’s important to have a stable power supply.

✅ Antennas

The type of antenna you use and where you place it makes a significant impact on the number of planes your receiver can pick up and how far it can reach. With a high-quality antenna and a non-obstructed view of the sky, your receiver should be able to pick up aircraft over 250 nautical miles away. The ideal antenna for flight tracking is omnidirectional and specifically designed for the reception of 1090 MHz or 978 MHz signals.

Antenna Placement Tips

1. Aim High. Try to place the antenna in a secure, high, and approachable location. A rooftop with an unobstructed view is an ideal location. However, if this is not possible, placing the antenna on the highest floor next to an external siding wall or a vinyl window is the next best alternative position. Always take precautions when setting up an antenna outdoors!

2. The antennas from FlightAware are omnidirectional. As a result, it can theoretically receive ADS-B signals from all directions. However, if you notice significantly more air traffic from a particular direction, e.g., if there is an airport nearby, you can maximize your position counts by placing the antenna closer to that airport direction with the fewest hindering objects.

3. Place the antenna away from metal, bricks, and concrete objects. These objects can degrade the ADS-B signals and prevent your ADS-B receiver from receiving the signals. For example, placing the antenna in the attic is not a good idea if you have a metal or concrete roof. If you have two external walls, one of which is concrete or stucco and the other is siding, placing the antenna next to the siding wall is preferred.

4. Be cautious of external RF parts between the antenna and receiver. For those who use an external amplifier and filter, alternate the sequence (filter before LNA vs. LNA before filter) to find the best option for you. If you place an LNA before the filter, be aware of RF-emitting devices around you, which can saturate the LNA and cause low reception.

You should use the Coverage Graph on your My ADS-B stats page as a reference to identify the directions where you may not be picking up as many messages and position your antenna accordingly. Our discussion forums are a great way to connect with the community on ways to improve your antenna setups and coverage.

If setting up an antenna outdoors is out of the question, the next best thing is an antenna placed next to a window with a clear view of the sky. Many people use small indoor coil antennas, which work fine, but an upgrade that we recommend is purchasing a high-quality outdoor antenna and using suction cups with bungee ties to hang it on a window like the one below.

 Using suction cups to prop up an antenna

If you think you can improve your coverage by upgrading your antenna or placing it in a better place, we encourage you to do so. We’d love to hear about your performance improvements and how you made them!

✅ Cables 

Your ADS-B antenna picks up aircraft transponder signals that need to travel to your receiver to be decoded. These signals travel through the cable that connects your antenna to your receiver, which is why it’s important to choose a high-quality cable that minimizes distortion and attenuation of the signal.

Good cables:

• Are weather-resistant Most ADS-B receivers are installed outdoors and can be subject to harsh environments. Look for cables that have an outside protective jacket rated for weather (i.e. resistant to snow, rain, and sun)

• Have a protective shielding layer This will reduce interference on the ADS-B signal. Outside radio interference from other electronic devices can affect the signal, and the signal traveling through the cable can also disturb other devices around it. Good cables have 80% shielding coverage and greater than 40 dB of effective shielding.

• Use the shortest length possible that is feasible for your installation Longer cables require the signal to travel a farther distance and can cause attenuation or signal loss. It is important to always use the shortest length of cable necessary to connect your antenna and receiver.

• Have a cable impedance of 50 ohms All components of your receiver should have the same impedance to prevent signal distortion. We recommend and provide components with 50 ohms impedance.

  

If you’ve received a FlightFeeder from us, you received a high-quality coaxial cable with the kit.

If you host a PiAware and your cable can be upgraded in any of these areas, doing so will increase the performance of your PiAware. We sell high-quality coaxial cables of different size lengths in our FlightAware online store (currently U.S. shipping only).

✅ Signal Amplifiers and Filters

What is a signal amplifier?

A signal amplifier is an electronic device that increases the power of a signal at its input. ADS-B signals transmitted from aircraft can often be degraded due to factors like signal interference, physical obstructions, and weather, especially at large distances between the aircraft and the receiver. A signal amplifier can be used to strengthen these weak signals once it reaches the receiver, thus increasing the range in which it can detect aircraft.

However, not only does the signal get amplified, but also the radio frequency (RF) noise present at its input, which can add unwanted distortion to the signal making it more prone to errors when decoding the ADS-B data. For this reason, radio receivers commonly use a special type of amplifier known as a low-noise amplifier (LNA), which is designed to minimize this additional noise.

Do you need an amplifier?

Yes, in the majority of cases, a signal amplifier will improve your ADS-B signal reception and range.

If you use our Pro-Stick or Pro-Stick Plus, there is a built-in SkyWorks 7150 LNA on the radio board so an additional signal amplifier is not needed. Our FlightFeeders come powered with the Pro-Stick.

What is a signal filter?

ADS-B receivers can be subject to noise that can interfere with the ADS-B signals it receives. This noise can be caused by factors such as RF interference from nearby FM radio stations and cell towers and electrical interference from other electronic devices and power lines near the receiver.

Signal filters are electronic devices that are designed to isolate and remove this unwanted noise and sits between the antenna and the radio receiver.

Do you need a signal filter?

It depends. If you live in an environment where there is potential for interference from other radio transmission or electronic devices, then you may benefit from using a signal filter. These places include:

• Urban areas with high-power radio transmitters such as towers for mobile phones, broadcast radio, or television

• Airports which have constant radio transmission from air traffic control communications

• Industrial areas with power lines, transformers, and other industrial equipment

Rural environments and areas with less noise would not need signal filters and can actually hinder your ADS-B signal reception.

Where can I find a signal filter?

FlightAware has built external band pass signal filters specifically designed for 1090 MHz and 978 MHz signals that you can purchase at our FlightAware Store (U.S. only) and other online vendors such as Pi Hut and Moonraker.

Our Pro-Stick Plus includes a built-in 1090 MHz filter that helps with the filtering of noise and is sufficient in most cases. However, your receiver can still benefit from a separate external filter in environments where the noise level is so high that it overwhelms the built-in amplifier.

In summary, signal amplifiers and filters can improve the performance of an ADS-B receiver depending on the hardware and surrounding environment. We encourage you to take some time to research and experiment with and without them to see if you can benefit from it.

To gauge performance improvements, you can monitor your receiver message rate through your local SkyAware interface and your position reports on your My ADS-B Statistics page. You can also compare your receiver statistics to people around you to see if there is room for improvement using the “Nearby Sites” table at the bottom of your My ADS-B stats pages.

✅ Internet Connection

One metric the ADS-B team monitors is how many receivers we’ve seen online in the past 2 days and how many we’ve seen online in the past 30 days. In a perfect world, the numbers should be relatively close to each other, but due to the nature of the community driven network, that is not the case. The primary reason for this is because people’s internet connections may not be reliable which causes the receivers connected to the network to fluctuate.

This month’s topic is about internet connections. You’ll learn how to measure the stability of your network connection and what you can do to maintain a long uptime to keep the FlightAware network healthy.

For PiAware users that use Wi-Fi and have access to the terminal, you can see the quality and strength of the Wi-Fi signal by entering the Linux command iwconfig (see output below). The “Link Quality” field shows you how good of a signal your Wi-Fi receiver is picking up, which can be affected by interference or obstructions. The “Signal Level” measures the strength of the Wi-Fi signal. The closer the signal level value is to 0, the stronger the signal. The more negative, the weaker the signal is.

Another way to determine the stability of your Internet connection is looking at the Feeder Check-In time on your My ADS-B Stats pages. Your receiver is designed to “check-in” with FlightAware approximately every 5-10 minutes to ensure it’s healthy. If you see a longer time, it may indicate a problem with the receiver, including the internet connectivity.

Things you can do to ensure Internet stability

• Use wired Ethernet In general, wired Ethernet connections are faster and more reliable than a Wi-Fi connection. A Wi-Fi connection is susceptible to interference from other electrical devices and physical objects can often block the signals.

• Have both Ethernet and wireless connection enabled The data feed to FlightAware will use the wired connection and if that doesn’t work it will fall back to using the wireless connection. If the wired connection becomes available again it will switch back to using the wired connection.

• Place your receiver and access point close to each other A router stowed away in a closet is not the ideal place for it. A receiver placed in the attic will work but the internet stability may be affected due to obstructions. If Ethernet is not an option, try placing them closer to each other.

• Upgrade your internet or router We realize this is not possible for everyone, but if it is, investing in a good internet, router, or Wi-Fi extender can help immensely.

What have you done to ensure your receiver is connected and online 24/7? Email us at and let us know!

✅ Lightning and Electrical Surge Protection

Over the past few months, we received some questions and comments from you all about ways to protect your receiver from lightning strikes and electrical surges.

Although many of your concerns are about lightning strikes to the antenna, the majority of electrical issues we see are actually caused by power surges from your home. The minimum precautionary measures we recommend you take is to use a power strip with surge protection on your ADS-B receiver (as well as all your electrical equipment). It’s a relatively cheap solution that can save your electrical equipment from this more common occurrence.

Lightning strikes directly to outdoor antennas are rare, but can happen. Although there is no single failsafe solution to protect from a direct lightning strike, some of our users who live in areas that are prone to thunderstorms use lightning arresters, such as this, to mitigate lightning damage. We also suggest ensuring your antenna is properly grounded either by you or a professional. 

We hope this blog post was able to help you optimize your receiver for reliability and performance. We would love to know if you tried any of these tips, or if you have others that have worked for you. Email us at [email protected] and let us know and we can share with rest of the community!

STAY IN TOUCH

Click the link below to visit the ADS-B Flight Tracking discussion forum on our website, or follow us on social media to stay up to date with the latest news!