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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Thu Jun 15, 2017 2:12 am 
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Akissack - FlightAware user avatar

Joined: Sun Jun 21, 2015 12:55 pm
Posts: 63
After several years of running adsb I've decided to get a FA dongle. You can see from the graphs that it did improve results. Very happy with my purchase.

Image


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Thu Jun 22, 2017 4:16 am 
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SoNic67 - FlightAware user avatar

Joined: Fri Jun 16, 2017 7:44 pm
Posts: 72
Location: Newport News, Virginia, USA
CXA007 wrote:
With my homemade 12 segment collinear antenna, I see traffic 250+miles out regularly, for about 14,000 position reports a day at the 200mn+ range..
Having outside on my 39th floor balcony helps too :lol:


That's all about the height there, you have a direct line of sight of more than 310 miles!
http://www.calculatoredge.com/electroni ... fsight.htm

My antenna is only on top of my garage. I hate you :lol:


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Thu Jun 22, 2017 11:25 am 
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abcd567 - FlightAware user avatar

Joined: Sat Feb 15, 2014 3:08 am
Posts: 2137
Location: Toronto CYYZ
SoNic67 wrote:
That's all about the height there, you have a direct line of sight of more than 310 miles!
http://www.calculatoredge.com/electroni ... fsight.htm

My antenna is only on top of my garage. I hate you :lol:

That's NOT all about the height. The contribution of height of RECEIVING antenna is much less than the contribution of height of the plane.
A plane at 40000 feet, contributes 283 miles to line of sight.
A receiving antenna at 15 feet height (garage roof) contributes 5 miles
A receiving antenna at 390 feet height (39th floor) contributes 28 miles.

With antenna above garage (15 ft above ground), the line of sight = contribution of RECEIVING antenna + contribution of plane = 28 + 283 = 311 miles
With antenna at 39th floor (390 ft above ground), the line of sight = contribution of RECEIVING antenna + contribution of plane = 5 + 283 = 288 miles

Improvement going from Garage roof to 39th floor = 311 - 288 = 23 miles


Image.Image

If the antenna is surrounded by tall houses/buildings or trees, which block its view of horizon, then raising antenna above the height of these obstruction does improve message count and range. Once antenna is above these obstructions, any further increase in height brings in very little improvement.


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Thu Jun 22, 2017 7:02 pm 
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SoNic67 - FlightAware user avatar

Joined: Fri Jun 16, 2017 7:44 pm
Posts: 72
Location: Newport News, Virginia, USA
Well yes and no... To me it is important if you have buildings (houses) around you. The further the plane is, lower to the horizon it will be. That means that my line of sight cannot reach the theoretical LOS because it will have objects in the way.
If you are at the 39th floor, probably not too many tall buildings are around you. Or at least that's what I think.

An object, even if smaller height than the antennas, if is situated between them can block the LOS. Imagine one in the middle of this figure:
Image

As my house antenna is only at 2 feet above roof, a house at 1 block away might block me - when plane is towards the extreme of my range.


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Wed Jul 19, 2017 5:44 am 
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mickey599 - FlightAware user avatar

Joined: Fri Nov 25, 2016 3:20 am
Posts: 3
Hi to all,
I saw that video on YouTube with that time-lapse and I liked it very much, so I found this thread and read all all 18 pages to see that it is not possible to implement all those fancy things because I use v1.15~dev and OpenStreetMap.
Is there any way that I can implement that advanced features, is there another thread or so?

I want to experiment with LNA-s and antennas and also to see what is best setup (pro stick plus vs. V3 and what are differences based on type of hardware that I use (C.H.I.P, RPi 2 - 3 and ODRIOD)
Many thanks to all in advance.


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Wed Jul 19, 2017 6:50 am 
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geckoVN - FlightAware user avatar

Joined: Sat Apr 30, 2016 12:14 pm
Posts: 12
SoNic67 wrote:
An object, even if smaller height than the antennas, if is situated between them can block the LOS.

This is absolutely true and it is made worse by the Fresnel Zone.
An object does not even need to be in the LOS to interfere with the signal.
So the more height you can get, the better.


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Thu Jul 20, 2017 9:09 am 
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nameredacted - FlightAware user avatar

Joined: Tue Jul 18, 2017 7:36 pm
Posts: 15
Overnight I had a ping at 200+nm recorded. Any way for me to look and see what/where it was? I just see it on the coverage graph on my stats page. I'm assuming atmospheric skip or a fluke because I've only tagged a handful in the 120-160 range and nothing over 160nm. Bone stock setup, antenna peaking through a roof vent in my attic, but still only about 20' elevation.

- had another, different direction, middle of the day but I missed it.


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 Post subject: Re: What is the Maximum Range I can Get?
PostPosted: Fri Jul 21, 2017 11:04 am 
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k6ls - FlightAware user avatar

Joined: Thu Jul 20, 2017 9:35 am
Posts: 5
nameredacted wrote:
Overnight I had a ping at 200+nm recorded. Any way for me to look and see what/where it was? I just see it on the coverage graph on my stats page. I'm assuming atmospheric skip or a fluke because I've only tagged a handful in the 120-160 range and nothing over 160nm. Bone stock setup, antenna peaking through a roof vent in my attic, but still only about 20' elevation.

- had another, different direction, middle of the day but I missed it.



I got 2 hits recorded at 250+ Miles
everything else is at 150 miles or less

thats my temporary setup with a RPi 3b, DVB dongle (zero filtering), ~30' coax to a ground plane antenna on my roof.

I have the FA dongle with filter coming and I plan on making the coax run about 10 ft,. My swag is an improvement of +3 dB for signal,
that should be a boost to my reporting capabilities.



UPDATE

I got the blue FA dongle today, and installed it. I just shutdown and replaced the dongle and reboot.. thats it.

aircraft in the 100-200 range are now "normal" and a few are showing in the 200-250 range

it's like a whole new world! 8)


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