Plane Spotters / Flight Radar Thread

Luke · 26 Feb 2018 at 17:11

I'm sorry to use this thread like google, but I cannot for the life of me work out how to generate a heatmap in either planefinder or VRS. Both are picking up from my Piaware receiver but I cannot work out how to generate the maps I've been seeing above.
What am I missing? :confused:

Ah, hadn't added the reveiver location in VRS config! Sorted now.

Luke · 27 Feb 2018 at 15:57

Not terrible with a small spider antenna. It will be interesting to see how it changes with a better antenna.

Nazbit · 27 Feb 2018 at 18:32

Changed to the Flight Aware branded 26inch 1090Mhz antenna a couple of days ago.

This is still just set up in an upstairs window by my desk but I'm now seeing around 1,200 aircraft per day as opposed to 900 before and around 120,000 position reports now up from 45,000 before.

Decent improvement in range too. Hoping to get it moved up in to the loft in the next week which should be better again.

Heatmap before:

Heatmap after:

Nazbit · 27 Feb 2018 at 18:37

Luke said:
Not terrible with a small spider antenna. It will be interesting to see how it changes with a better antenna.

Do you have any pictures of the antennas you have built so far? if you're comparing different types of home made antennas would you be able to post up your findings?

You have a good central location to cover most ofnthe country.

Feek · 27 Feb 2018 at 18:45

It's worth remembering that commercial aerials may not work as well as homebrew ones.

My two element J-pole in the loft receives almost as many aircraft/day as the FlightAware stick which is mounted outside and about ten ft higher, the main difference is the number of reports received/day. The external one receives a lot more.

Taking from the FA stats.

My internal receiver sees an average of 3,156 aircraft and 805,679 positions per day
My external receiver sees an average of 3,213 aircraft and 950,992 positions per day

(yes, I know that's a lot - My receivers generally sit in the top three in the UK FA charts, currently at positions 2 and 3).

If I could be bothered to fully weatherproof my internal aerial and mount it externally, I think it would probably outperform the FA stick.

Coax is important - The longer the run, the more the loss. My internal receiver is connected directly the the aerial and the external one has less than a foot of cable.

Here's my external receiver heatmap from Planefinder.

Luke · 27 Feb 2018 at 20:58

At the moment I'm running a 4 leg spider into a connector then into the flightaware USB stick. No cable in sight.
I've tried an 8 legged spider but got worse results, possibly construction issues.
Still trying different locations in the loft but the most reliable has turned out to be sat on the floor dead centre. I've connected the unit to a gorillapod and hung it off various rafters hoping for better numbers but none have been better than the floor as yet. I'm trying to clear the loft out to give further options.

Luke · 28 Feb 2018 at 20:02

Nazbit said:
Do you have any pictures of the antennas you have built so far?

This is the current one:

I'm thinking that the LAN cable could be interfering so will try to either raise the antenna or getva right angle connector. I found the screw version better than the soldered version and the 8 legged soldered version. I suspect I may have put too much heat into the connection and caused an issue. New soldering iron required I think before I try again.

Luke · 2 Mar 2018 at 14:30

My eBay antenna arrived from Slovakia yesterday. Got to fitting it today and very impressed for the money. It was half the price of the Flightaware antenna.
The heatmap is far more even and I'm seeing stuff over 200 miles away.

Nazbit · 2 Mar 2018 at 20:30

Moved mine up in to the loft yesterday evening, needs mounting properly just trying out different positions for now. Nice increase in range I'm routinely seeing 300-350 miles and occasionally as far as 400. I've also got a filter to try out but not sure how much benefit that will bring in a rural area.

Feek said:
It's worth remembering that commercial aerials may not work as well as homebrew ones.

My two element J-pole in the loft receives almost as many aircraft/day as the FlightAware stick which is mounted outside and about ten ft higher, the main difference is the number of reports received/day. The external one receives a lot more.

Your stats are outrageous!

Are these homemade contraptions hard to make? Do you need to be good with a soldering iron? I'm guessing that the solder on each element should not touch, thats the part I would find difficult. I can solder two cables together easily enough but I'm not very good at being precise in small areas.

Luke said:
My eBay antenna arrived from Slovakia yesterday. Got to fitting it today and very impressed for the money. It was half the price of the Flightaware antenna.
The heatmap is far more even and I'm seeing stuff over 200 miles away.

Looks like a good improvement, which antenna was it?

Nazbit · 2 Mar 2018 at 20:51

Hi @Feek could you help with a few questions please?

1. Can the flight aware 26inch antenna be mounted upside down? Still vertically but pointing down instead, would that mess it up?

2. How bad is the coax loss? At the moment its in my loft with 1m of coax. If I was to move it outside, I'd loose the roof and have clear line of sight to the sky and would be perhaps 3 - 4m higher than it is now. The disadvantage is that I'd have to increase the coax length to about 10m. Is this worth trying or would the losses outweigh the benefits of the new location? I don't think mounting the Pi outside with POE is an option for me, I'd have to go with the coax.

3. I've not tried fiddling with the gain yet, I understand that it is about finding the right signal to noise ratio. Are there any scripts or utilities that either do this automatically or that can provide some numerical data for comparison? Or is it just a case of trying each level for a few days and seeing how the range/no of aircraft / range changes?

Thanks

Feek · 2 Mar 2018 at 23:21

Nazbit said:
Moved mine up in to the loft yesterday evening, needs mounting properly just trying out different positions for now. Nice increase in range I'm routinely seeing 300-350 miles and occasionally as far as 400. I've also got a filter to try out but not sure how much benefit that will bring in a rural area.

Check what units you're using - I very much doubt you're seeing anything routinely out to 350 miles. I get a few between 250 and 300 miles and hardly ever anything beyond that. Consider this graph, the figures are lower than normal because of the lack of aircraft in the skies over the last few days and the additional attenuation caused by the weather. You may be reading kilometres rather than miles.

Nazbit said:
Are these homemade contraptions hard to make? Do you need to be good with a soldering iron? I'm guessing that the solder on each element should not touch, thats the part I would find difficult. I can solder two cables together easily enough but I'm not very good at being precise in small areas.

Very straightforward - There are only two places to solder on the J-Pole I use.

Nazbit said:
Hi @Feek could you help with a few questions please?

1. Can the flight aware 26inch antenna be mounted upside down? Still vertically but pointing down instead, would that mess it up?

No, don't mount it upside down, it needs to go the correct way.

Nazbit said:
2. How bad is the coax loss? At the moment its in my loft with 1m of coax. If I was to move it outside, I'd loose the roof and have clear line of sight to the sky and would be perhaps 3 - 4m higher than it is now. The disadvantage is that I'd have to increase the coax length to about 10m. Is this worth trying or would the losses outweigh the benefits of the new location? I don't think mounting the Pi outside with POE is an option for me, I'd have to go with the coax.

Naturally it depends on the cable you're using but unless it's something very good, you're going to suffer a lot with a 10m run of coax. If you're using RG-58 or equivalent then you'll lose around 75% of your signal. RG-213 is better but at that frequency, you're still losing 50% of the received signal. Fitting a mast head pre-amplifier will help.

Nazbit said:
3. I've not tried fiddling with the gain yet, I understand that it is about finding the right signal to noise ratio. Are there any scripts or utilities that either do this automatically or that can provide some numerical data for comparison? Or is it just a case of trying each level for a few days and seeing how the range/no of aircraft / range changes?

There's a lot of discussion about gain on the FlightAware forums and some scripts you can run. When I'm doing a gain calculation, I run the script for eight hours or so - It does some measurements at different gain levels and then at the end, you get a list of the different figures and the associated number of aircraft/positions for you to choose the best.

Luke · 3 Mar 2018 at 10:16

This new antenna has massively improved the heatmap.

Not bad for £27!
https://www.ebay.co.uk/itm/Antenna-...COL1090-5-H-/302647511627?hash=item4677328a4b

Nazbit · 3 Mar 2018 at 11:58

Feek said:
Check what units you're using

Oops I think you're right!

Thanks for all of the answers.

SuperOwl86 · 3 Mar 2018 at 21:30

neodude said:
Clicky

Thanks for that arrived yesterday and set up this morning.

SuperOwl86 · 4 Mar 2018 at 10:37

Had a bit of pants night where for some reason the receiver did not pick anything up. This morning finally got something going.

I dont expect much with it being internal and not being able to see other the trees. Although yesterday I was picking stuff up in the Wash and bit further into the North sea.

Luke · 4 Mar 2018 at 10:44

I can't see that pic unfortunately.

SuperOwl86 · 4 Mar 2018 at 15:55

Looks like I have a problem somewhere getting the error saying it is wedged.

Luke · 4 Mar 2018 at 18:27

I see you are very close to me. Would you like to try my home made spider?

SuperOwl86 · 4 Mar 2018 at 18:47

Think the wedge problem was down to the Pi overheating since I have moved it seems to have cooled down and been stable since. Not sure if I would gain much due to the position of my antenna being on my bedroom windowsill.

Luke · 4 Mar 2018 at 19:19

I think I was getting 250-300 messages/sec in my window but I'm quite elevated.