Topic: FlightRadar24 uses TDOA for locating aircraft

[W3DRM]

While not related to Blitzortung or anything weather, I came across an article about how the FlightRadar24 servers use TDOA (Time Difference Of Arrival) for locating the position of a particular aircraft. It is similar to the Blitzortung servers basing the input on TOA (Time Of Arrival) of signals for locating lightning strikes.

The similarity continues in that FlightRadar24 uses the inputs from four or more of the many ADS-B receivers scattered around the world in conjunction with GPS timestamps to pinpoint where an aircraft is. If the aircraft is ADS-B equipped and sending out that data, then the servers do not need to calculate the positioning data as it is part of the ADS-B data stream from the aircraft.

EDIT: Note this TDOA is called MLAT (Multilateration) which is used when the positional data is not included in the Mode-S transmissions.

All of this came up when I started looking into installing an ADS-B receiver of my own here at home. After some additional digging, I discovered FlightRadar24 is looking for more receiver sites all over the State of Nevada (and many others too). They are offering FREE receivers and a complete package, including an external ADS-B 1090Mhz antenna. All you have to do is to apply for it and then fill-in an application. They also require that you send in photos of your proposed location with views to N, E, S & W. The package is self-contained and is fully plug-n-play. It connects directly to your router and automatically configures itself. A bonus is that for those who feed their data to their servers, get a free Premium FlightRadar24 account.

I submitted my application and photos last week and yesterday, I got the acceptance email. My new equipment will be shipped in a week or so! 

I guess this is just one more thing for us techno junkies to get into. If anyone is interested, here is a link to the FlightRadar24 website:

• http://www.flightradar24.com/increase-coverage/

Is there anyone else on this forum who are current feed sites for FlightRadar24? If so, I'd like to know a bit more about what your experiences have been with this system and what kind of equipment you are using. Guess this should probably be in the Chit Chat section but since they use similar methods of location detection I started out here in the BO area.

Mods, feel free to move this wherever you deem appropriate...

[Jumpin Joe]

Just sent in my application.  Do you happen to know what kind and size the antenna is that they are using?

[WA4TM]

I was going to put in an application, but when I got to the bottom of the form it asked if you had a 360° view, that killed it for me I have trees out back that I AIN'T gonna cut..... I have a 40ft tower out back that is not full yet!! LOL. But the trees are 75-80 ft high..  So I am wondering how far the 360° view needs to be, anyone have a guess?

Edit: I went ahead and filed an application, I'll let them judge the location... so we will see what happens....

[WA4TM]

Just sent in my application.  Do you happen to know what kind and size the antenna is that they are using?

Here is one they show on the application page. I doesn't look to be much over a foot/foot and a half high judgeing from the bracket and coax..

[ocala]

http://www.radarbox24.com/was also willing to send out free receivers but my email response was that they will "evaluate" the situation even though there is very little coverage in the states.
Flightradar24 on the other hand has outstanding coverage in the states as well as my area here in Florida.
 

[Jumpin Joe]

Just sent in my application.  Do you happen to know what kind and size the antenna is that they are using?

Here is one they show on the application page. I doesn't look to be much over a foot/foot and a half high judgeing from the bracket and coax..

No problem with that on top of the chimney.

[CamarilloWX]

Out of curiosity what would one do with an ads-b receiver if not sending data to Flightradar24?

[W3DRM]

The length of the supplied antenna is 38cm which is 14.96".

I would suggest that anyone who is interested go ahead and complete the application. You can't lose anything by submitting it. As far as trees go, that may be a factor but let them make that decision. I have also specified the max length of antenna cable at 10 meters. They also offer a shorter 5m cable but I went with the longer due to the distance from my rooftop into my office where the router is located. I suspect, with a suitable waterproof enclosure the receiver/electronics could go outside but temperatures may be an issue. It's mostly an unknown to me at the moment. I'll find out once I get the equipment.

The receiver is 3.9" x 2.3" x 1.2".

Am hoping many of you on this forum look into this offering. Who knows, we may have to add a separate FlightRadar24 section to the forum. Oops, it's not weather-based...

[WA4TM]

The length of the supplied antenna is 38cm which is 14.96".

I would suggest that anyone who is interested go ahead and complete the application. You can't lose anything by submitting it. As far as trees go, that may be a factor but let them make that decision. I have also specified the max length of antenna cable at 10 meters. They also offer a shorter 5m cable but I went with the longer due to the distance from my rooftop into my office where the router is located. I suspect, with a suitable waterproof enclosure the receiver/electronics could go outside but temperatures may be an issue. It's mostly an unknown to me at the moment. I'll find out once I get the equipment.

The receiver is 3.9" x 2.3" x 1.2".

Am hoping many of you on this forum look into this offering. Who knows, we may have to add a separate FlightRadar24 section to the forum. Oops, it's not weather-based...

It might count if the flight was rained out!!!!   

I edited my post above...

[DaleReid]

what kind of a data load will it place uploading all the stuff via internet? 

I know most of what I get charged for is incoming service, but will they stream out data at how much per hour or day?

[W3DRM]

Out of curiosity what would one do with an ads-b receiver if not sending data to Flightradar24?

There are other groups who collect and display that data. Just Google for ADS-B data and I think you'll find quite a bit of info.

[W3DRM]

what kind of a data load will it place uploading all the stuff via internet? 

I know most of what I get charged for is incoming service, but will they stream out data at how much per hour or day?

Great question but I don't know the answer. They did have me perform a data test to see what my upload data transfer rate was. I'll send an email to their support group and see what they say. Will let you know when I get an answer back.

[W3DRM]

"Data consumption: 200-800 MB/month depending on coverage" per http://www.flightradar24.com/free-ads-b-equipment

In today's world that's not much data to contend with.

Here is a link to some more information on the hobby of plane spotting:

• http://www.flightradar24.com/RadarspottingGuide.pdf

There are a bunch of reference links on the last page. Should keep you busy for quite a while... 

[dfroula]

Very cool. I sent in my application today. It seems like they are looking for additional Chicago-area ORD, MDW, and RFD coverage. I'm located at roughly the center point of these three airports, so I'm hopeful that I will be accepted for the free hardware.

I played around with an ACARS soundcard/software decoder 10 years or so ago, connected to the discriminator output of one of my Yaesu FT90R transceivers. It worked fairly well. This seems much more comprehensive and real-time.

Don

While not related to Blitzortung or anything weather, I came across an article about how the FlightRadar24 servers use TDOA (Time Difference Of Arrival) for locating the position of a particular aircraft. It is similar to the Blitzortung servers basing the input on TOA (Time Of Arrival) of signals for locating lightning strikes.

The similarity continues in that FlightRadar24 uses the inputs from four or more of the many ADS-B receivers scattered around the world in conjunction with GPS timestamps to pinpoint where an aircraft is. If the aircraft is ADS-B equipped and sending out that data, then the servers do not need to calculate the positioning data as it is part of the ADS-B data stream from the aircraft.

EDIT: Note this TDOA is called MLAT (Multilateration) which is used when the positional data is not included in the Mode-S transmissions.

All of this came up when I started looking into installing an ADS-B receiver of my own here at home. After some additional digging, I discovered FlightRadar24 is looking for more receiver sites all over the State of Nevada (and many others too). They are offering FREE receivers and a complete package, including an external ADS-B 1090Mhz antenna. All you have to do is to apply for it and then fill-in an application. They also require that you send in photos of your proposed location with views to N, E, S & W. The package is self-contained and is fully plug-n-play. It connects directly to your router and automatically configures itself. A bonus is that for those who feed their data to their servers, get a free Premium FlightRadar24 account.

I submitted my application and photos last week and yesterday, I got the acceptance email. My new equipment will be shipped in a week or so! 

I guess this is just one more thing for us techno junkies to get into. If anyone is interested, here is a link to the FlightRadar24 website:

• http://www.flightradar24.com/increase-coverage/

Is there anyone else on this forum who are current feed sites for FlightRadar24? If so, I'd like to know a bit more about what your experiences have been with this system and what kind of equipment you are using. Guess this should probably be in the Chit Chat section but since they use similar methods of location detection I started out here in the BO area.

Mods, feel free to move this wherever you deem appropriate...

[CNYWeather]

http://www.radarbox24.com/was also willing to send out free receivers but my email response was that they will "evaluate" the situation even though there is very little coverage in the states.
Flightradar24 on the other hand has outstanding coverage in the states as well as my area here in Florida.

Tried the "Add Coverage" link (which doesnt work in chrome). Looking for anywhere in North America except where I am.

North America
Anywhere except the N.E. and subject to our analysis

[W3DRM]

http://www.radarbox24.com/was also willing to send out free receivers but my email response was that they will "evaluate" the situation even though there is very little coverage in the states.
Flightradar24 on the other hand has outstanding coverage in the states as well as my area here in Florida.

Tried the "Add Coverage" link (which doesnt work in chrome). Looking for anywhere in North America except where I am.

North America
Anywhere except the N.E. and subject to our analysis

CAUTION - The link in ocala's post is for a different flight tracking website. The terminology is very similar as are the displays. Be sure you are going to http://flightradar24.com. And yes, radarbox24 does appear to have problems with Chrome but flightradar24 works just fine in Chrome.

I do see that New York area has the following needs:

• NEW YORK
  • Jamestown
  • Rochester
  • Corning
  • Albany
  • Plattsburgh
  • LGA airport
  • JFK airport

[saratogaWX]

I gave them my application, Don.  Don't know if they'll need another south Bay Area site though

[Mitch W4OA]

Just sent in my application for FlightRadar24.

Mitch W4OA

[CNYWeather]

CAUTION - The link in ocala's post is for a different flight tracking website. The terminology is very similar as are the displays. Be sure you are going to http://flightradar24.com. And yes, radarbox24 does appear to have problems with Chrome but flightradar24 works just fine in Chrome.

I do see that New York area has the following needs:

• NEW YORK
  • Jamestown
  • Rochester
  • Corning
  • Albany
  • Plattsburgh
  • LGA airport
  • JFK airport

Yep I saw those areas. Thanks! They are in different parts of NY. I guess the center of our fine state is all covered.
I sent them an application for the heck of it. Maybe being smack in the center of NY will be good.

Tony

[Jumpin Joe]

Received my "Step 2" e-mail this morning.  Now I've got to climb on the roof for pictures, then send them and the other info they are requesting back. If they like what they see I will become a tracker.

Joe

[SoCalBrian]

FR24 and Radarcape using the BeagleBone computer in the unit.
http://beagleboard.org/Products/BeagleBone

More information on the antenna being used by FR24 can be found on this site. modesbeast.com in the web shop store.

Wiki about ADS-B (Automatic dependent surveillance-broadcast)
http://en.wikipedia.org/wiki/Automatic_dependent_surveillance-broadcast

Some other sites providing free ADS-B kits.

FlightAware Free FlightFeeder kit
(FlightAware offers a free Enterprise Account (USD$89.95/mo value) to users who share their data
with us.
http://flightaware.com/adsb/
http://flightaware.com/commercial/premium


Planefinder.net Free ADS-B Equipment Kit.
http://planefinder.net/about/coverage/


Radarbox24 - Free Radarbox hardware.
https://www.radarbox24.com/addcoverage
http://www.airnavsystems.com/contact.php


If you don't want the above free kits. You can get your own box and upload to many other
networks(Planeplotter,FlightAware,Flightradar24,RadarBox24, or any other networks.
http://www.modesbeast.com/radarcape.html
http://wiki.modesbeast.com/Radarcape:Contents


Planeplotter software.
www.planeplotter.com

Virtual Radar Server - Display your Mode-S/ADS-B data.
http://www.virtualradarserver.co.uk/

20 ADS-B receivers compared.
http://www.airplanetrack.com

ADS-B Hardware and Software technical Matters
http://www.radarspotters.eu/forum/index.php/board,40.0.html

[W3DRM]

Received my "Step 2" e-mail this morning.  Now I've got to climb on the roof for pictures, then send them and the other info they are requesting back. If they like what they see I will become a tracker.

Joe

I didn't bother climbing up on my roof. I just walked around the house at ground level and took my pictures. That seemed to work for me.

I am going to add a triangular piece of 3/4" plywood to the eve of my house and place the antenna bracket on it. I'll also be placing my external webcam housing on that same piece of plywood. Will most likely use an extension piece of antenna mast so I can get the antenna above the level of the roof peak.

[Jumpin Joe]

Received my "Step 2" e-mail this morning.  Now I've got to climb on the roof for pictures, then send them and the other info they are requesting back. If they like what they see I will become a tracker.

Joe

I didn't bother climbing up on my roof. I just walked around the house at ground level and took my pictures. That seemed to work for me.

I am going to add a triangular piece of 3/4" plywood to the eve of my house and place the antenna bracket on it. I'll also be placing my external webcam housing on that same piece of plywood. Will most likely use an extension piece of antenna mast so I can get the antenna above the level of the roof peak.

Don, I think that's what I will do. Knee acted up today, could not go up on top. Was going to wait for my son to come over in a few days.

Thanks,
Joe

[W3DRM]

In case anyone has seen the article on the flightradar24 forum that mentions a person getting hit for import fees, see the following response from the support group at flightradar24 to my question about this. I also asked about lightning protection (guess that helps to keep this thread in the realm of weather  ).

• FlightRadar24 Support Response:
  
  • The equipment is shipped from Germany with accompanying documentation declaring that the goods are a free sample that remain the property of Flightradar24 AB.  There should be no import duty or tax to pay and the one forum post that mentions high import duty has not been verified and doesn't reflect our experiences to date.
  
  
  • We do not require any lightning protection.

I am glad to see this subject has received pretty good acceptance and interest by the WXFORUM community. I think it is a natural addition to our endeavors to increase our knowledge and offerings to the general public. Some folks are already posting the flightradar24 screens on their website. Now, we will have the opportunity to add our own data too.

One other thing I might mention. I had wondered how we could tell, if at all, whether the data seen on the flightradar24 screens came from us or some other source. After reading through more of the documentation, it appears that once we get our equipment and get it installed, we will make a request for a key of some kind. That key is apparently our ID and will shown as a part of the display. I may be wrong but I think it is the field shown as "Radar" on the screen for a particular aircraft.

[dfroula]

I climbed on the roof a few hours ago for my pics, as it was a nice, warm day here.  It was steeper than I remembered! 

In the mean time, I ordered a couple of these:

http://www.nooelec.com/store/sdr/sdr-receivers/tv28tv2-sdr-dvb-t-usb-stick-set.html#.U0cpi_xOVCp

They are European-standard digital TV tuners that have been modded for SDR (Software Defined Radio) operation. There's some nifty free software that turns it into a general purpose receiver that covers 25MHz-1750MHz, with excellent sensitivity at the 1090 MHz ADS-B frequency. There is additional free software that adds ADS-B tracking capability.

I just pieced together an 8-element co-linear antenna tuned for 1090 MHz with a length of RG-6 coax. It went together in about an hour:

http://www.balarad.net/

The receiver dongle comes with a useless remote control and small European TV antenna. It uses an MCX connector for the antenna. I'm going to put one in a box with an MCX to "F" chassis connector and a USB extension cord for the computer connection.

I've wanted to fool around with an SDR for a while regardless of whether I get approved for the free setup.

Don
WD9DMP