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Author Topic: How to get this kind of range ?  (Read 9281 times)

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UFO

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How to get this kind of range ?
« on: July 14, 2024, 01:09:14 PM »
can anyboday tell me how this guy is getting such a huge range using his RASPBERRY pi setup ?

Runway 31

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Re: How to get this kind of range ?
« Reply #1 on: July 14, 2024, 02:16:01 PM »
It all depend on his antenna hight and the surrounding topography.  If you can get your antenna high above the surroundings at its location with no obstructions to its view it is achievable.  Hight is king with a clear view around.  An antenna on a hill top with see further than an antenna in town with higher buildings, trees and high hills, mountains nearby

Alan

UFO

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Re: How to get this kind of range ?
« Reply #2 on: July 14, 2024, 04:19:44 PM »
I installed my ADS-B antenna on the roof of the 3rd floor with an unobstructed view of the sky. However, I'm only picking up signals from about 100 nautical miles away. There's a 2G/3G/5G cell phone tower within 30 meters (opposite my ADS-B antenna). Could this be interfering with my reception? yes i am using 1090MHz filter !

Runway 31

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Re: How to get this kind of range ?
« Reply #3 on: July 14, 2024, 06:09:28 PM »
Yes it probably will cause issues, are you using the correct filter for your country

Alan

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Re: How to get this kind of range ?
« Reply #4 on: July 15, 2024, 12:58:20 AM »
I have a clear view of the ocean to the west, but hills at 5 degrees up to the South and 2.5 degrees up to the North. East, where I get almost nothing, is more like 15 degrees up.

I have gotten 298NM to the west, which is straight out to sea, but am nearly blind the east, due to hills. South I only get 70NM and North a little over 100NM, all due to hills.

My antenna is about 183m above sea level, so my visible horizon out to sea is about 27NM.  I did have my antenna 30m lower, and the range was almost the same. I only lose a few NM to the horizon at 155m, so the dominant issue for me is the hills.

The aircraft altitude gives it the range to reach me. An aircraft at 40,000ft would have a visible horizon of about 220 NM If the signal skims to sea, I should get about 247NM range (my 27NM + the aircrafts 220NM).  I actually get quite a bit more, depending on the atmospheric conditions. I'm currently getting only about 270NM. It jumps up and down with the weather.

I looked up this location, and it is only 10m above sea level, so the land around their station must be pretty flat for a considerable distance.



abcd567

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Re: How to get this kind of range ?
« Reply #5 on: July 15, 2024, 02:24:59 AM »
@UFO
Click Here: Do I Need A Filter?


@rob
(1) Click Here: What is the Maximum Range I can Get?



(2) Contribution of Antenna Height and Aircraft Height to Range





(3) Antenna Obstruction and Range



« Last Edit: July 15, 2024, 02:32:16 AM by abcd567 »

[email protected]

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Re: How to get this kind of range ?
« Reply #6 on: July 15, 2024, 05:57:02 AM »
Well illustrated :)

[email protected]

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Re: How to get this kind of range ?
« Reply #7 on: July 15, 2024, 10:37:09 PM »
Keep you antenna cable length short too. Cable loss is very high at 1.09GHz. It does depend on the cable type you are using, and who made it.

You could put the Pi outside in a waterproof box, and run an outdoor ethernet cable to it, rather than running a longer antenna cable.  You could also use a long USB cable, and put the FlightStick closer to the antenna. (or both)

For the common LMR200 and LMR240 cables (about 5-6mm diameter): At 5m, the loss will be about around 30%; By 10m, the loss is going to be around 50% . Still viable signal strengths, but don't make the cable longer.



« Last Edit: July 16, 2024, 07:49:56 AM by [email protected] »

UFO

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Re: How to get this kind of range ?
« Reply #8 on: July 21, 2024, 01:43:56 PM »
Thank you all for your insightful replies, BTW does this thing help in increasing my range " 1090MHz ADS-B Filtered Preamp" ?

[email protected]

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Re: How to get this kind of range ?
« Reply #9 on: July 23, 2024, 12:21:55 AM »
If you aren't getting the range because of terrain or other obstructions (e.g. hills or buildings) then probably not.  The hills don't need to be much higher than you, to restrict your range. Antenna height and location would likely help more.

An amp might help, if you have a long cable, and the amp is installed close to the antenna (before the long cable run, not after).  If the cable run is short, then the the receiver should have enough gain by itself.  A signal still isn't going to get past terrain, but you might get more aircraft showing up, if they are in line of sight.

The same is true of using higher gain antennas. They also compensate for the cable loss. To get the gain, the antenna focuses on a smaller area of the sky (just like a magnifying glass restricts your view to a smaller area). Terrain is still your enemy. It's often a try it an see situation.

Try moving the antenna up a little, and in different locations on the building. It isn't going to be a magic fix, but it may help a little.

I just moved my antenna 1/2 a meter. I now have much better view south, but worse north.  The small change in angle to the distant terrain is likely now letting me see around a hill to the south, but I am now being blocked by a hill to the north.

« Last Edit: July 23, 2024, 10:18:03 PM by [email protected] »

highchain

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Re: How to get this kind of range ?
« Reply #10 on: August 04, 2024, 11:59:27 AM »
@UFO: You need a good antenna as high as possible, than use a very short low loss cable to connect to a LNA and from there either to a filter, or direct to your receiver. Also the gain is extremly crucial to your sucess. If you go to high you will overload your dongle.
try to ssh to your pi and run the following command:

awk "$(cat /run/dump1090*/stats.json| grep total | sed 's/.*accepted":\[\([0-9]*\).*strong_signals":\([0-9]*\).*/BEGIN {printf "\\nPercentage of strong messages: %.3f \\n" , \2 * 100 \/ \1}/')"

The result should be around 5%, if your higher reduce your gain step by step.

Here is what I use:
Vinnant CC1090/9-PSE => 30 cm HDF 400 => Uputronics prefiltered Amp powered via USB cable => three meters HDF 400 => Sysmocon cavity filter => 10 cm HDF 400 cable=> ADSBExchange usb stick (blue) => via USB-Kabel attached to a Raspi 4 powered via POE hat-pack.

Dump1090-fa gain currently set to 20.7. (just to use as a reference)

Hope that helps!

Greetings from Germany,

Marcus

https://www.radarbox.com/stations/EXTRPI603573

Vinnant CC1090/9-PSE
30 cm HDF 400 cable
uputronics prefiltered amp powered via USB cable
three meters HDF 400 cable
sysmocon cavity filter
10 cm HDF 400 cable
ADSBExchange usb stick (blue)
via USB-Kabel attached to a raspi 4 powered via POE hat-pack.