Flightaware and FR24: Number of planes seen/tracked


#1

Operating conditions: Same Flightaware antenna/RPi3 combo feeding both Flightaware and FR24. As per respectives websites, FR24 consistently shows around 5 or so more planes seen/tracked.

<EDIT: I meant to write around 5 or so more planes, not 5 %. Sorry.>

What could account for this discrepancy? Deconding/feeding software?

Not to mention the number of positions, but this is more complicated, I guess, as each seem to use different nomenclature/definition.

Thanks.


#2

In my case, and apart from one odd day, over the past two weeks FR24 and FA have been within 1 or 2 aircraft of each other. In most case FR24 has reported the higher figure. As the data on hits and positions is not reported in the same way, yes hard to call.


#3

Thanks. I meant to say 5 or so more planes, not 5%. Don’t recall Flightaware ever reporting more planes than FR24. Not a big deal, just trying to understand/learn more.


#4

We don’t get that many planes down here in the remotest capital city in the southern hemisphere, but one thing that does puzzle me is the disparity between FR24 and FA range/coverage figures. FA is much more generous and aligns to what my local daily coverage figures show.


#5

Remotest capital city in the southern hemisphere? Curious… where? I’m a southerner, but now living in the northern hemisphere.

As for range/coverage figures differences, I have been observing that too. FA appears to be more ‘generous’. This was likely going to be my next question.:wink:

I’m new to the ADS-B tracking hobby. As hamradio is kind of limited to my modest station right now, due to the low phase of the sunspot cycle, I was looking for something else radio related to learn and play with.

The biggest question mark I still have in my mind, is why the number of tracked planes collapsed. I have changed hardware many times, except for the antenna location. Had I not made screen captures of my past tracking totals, I would doubt my own memory. The only explanation left, as I was told early on, is a reduction in the number of flights over my ‘airspace’. Still hard to believe that a reduction of half to 2 thirds is possible so abruptly.


#6

I get that every so often–it correlates to a weather event in the Eastern and Northeastern USA. There have been 4 large storms this winter and each time, my count drops significantly for about 2 days then ramps up. Living only 100NM or so outside of Orlando Florida (Disney World and Universal Studios) I get a bunch of Midwest and European traffic, so I don’t drop as much as others, but it’s clearly noticeable.


#7

That’s understandable. In my case, the drop happenned last September, never to recover.


#8

Looks like a ‘hardware gone bad’ situation.
Ingress of moisture/water inside Antenna, coax from antenna to receiver (DVB-T/Pro Stick), connectors.

Another possibilty is AC to 5v DC power adapter gone bad.

My AC to 5V DC adapter 2500mA (2.5 Amp) worked good for about a year then gone bad. Pi still worked, but red LED often flashing (should be constantly lit), and performance dropped.

Purchased a new power adapter AC to 5V DC 3000 mA (3 Amp), and it solved the problem.


#9

Every single hardware piece has been replaced. No coax is used. The complete installation is inside the garage, it has always been there. No moisture/water seen/detected.

I had power supply problems before getting into the ADS-B bandwagon. I learned that lesson. :rofl:
Just to be sure, I went to check the RPis, I have two currently, the RED led is steady on, not flashing.

The two receiving ‘stations’ show similar performance. The minor difference is due to the antennas. The main one uses an FA antenna, while the other, a trimmed down RTL mag mounted on a pizza pan.