FlightAware Discussions

Multilateration and

FlightAware ADS-B Flight Tracking
#1

Hi everyone, just joined Flight Aware this morning and I have a couple of questions. The first one is How do I enable MLAT?, and the second is what is the best aerial for ADSB?.
At the moment I am using a RPi 3B with a NooElecNESDR Smart with a weird(to me) aerial that I made yesterday( if i remember its 1/4 wave with ground plane, whatever that means, I saw the thing on Youtube) its not doing that bad as Ive picked up a few aircraft just off the Thames and North Norfolk( Im in Soliull) but like a lot of people I think it could do better hence the aerial question.
Im a complete novice to this ADSB lark and would like to make my own aerial so…any suggestions??.

Chris

#2

Enable MLAT requires that you are setting up your location properly. This can be done in your profile You have a gear on the right side of the orange bar:
image
Click on it and a box will open where you need to add your location properly by either selecting it or entering the coordinates. On next restart of Piaware MLAT should work after a couple of minutes.

I assume this device does neither have a filter nor an amplifier built in. Depending on your area this could be required for improvement of the reception.

A regular stick has a wide frequency area while for ADS-B only 1090 MHz is relevant. So it’s always a good idea to filter everything out. I would suggest to read the different threads here

For the antenna you can go with a DIY, there are also good threads about it in the Forum

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#3

Thank you for the reply, you were spot on and it is now working. I think I am going for a home built antenna( Colinear ) and will look at the filter/amplifier as well,thanks for your help.
Expect more questions.

Chris

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#4

Start with a quarter wave so you have a comparison when building the colinear.
At least then you notice if the colinear didn’t quite work and has bad performance.

These two should be an easy build:
Three Easy DIY Antennas for Beginners - #2 by abcd567
QUICK SPIDER - No Soldering, No Connector

If you already have such an antenna, try tuning the whip a bit (changing whip length for example by cutting the whip and then attaching another part that can be moved up / down by soldering).
I personally ended up with a whip at 65 mm instead of 68 mm and it made a difference.

Instead of the typical coax colinears also take a look at this colinear: G7RGQ Antenna 1090MHz

When comparing antennas or tuning it a bit there are a quite a few tools that can be helpful in regards to judging ADS-B reception.
Due to obvious bias i’ll list some stuff i maintain: graphs1090
Also useful in my opinion: tar1090 pTracks feature and displaying the heywhatsthat range outline, see the tar1090 github page for installation and how to use those features.
You’ll find links to tar1090 and graphs1090 here:
Raspbian Lite: ADS B receiver · wiedehopf/adsb-wiki Wiki · GitHub

(graphs1090 and tar1090 will work fine with dump1090-fa and won’t disrupt any feed client you might have)

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