The weather model based on ADS-B data was [very recently] discussed here:
https://news.ycombinator.com/item?id=44734515
The article linked to this book, which is very comprehensive.
The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
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Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#12DOI: https://doi.org/10.34641/mg.11 Source files/code: https://mode-s.org/ Synopsis: In the last twenty years, aircraft surveillance has moved from controller-based interrogation to automatic broadcast. The Automatic Dependent Surveillance-Broadcast (ADS-B) is one of the most common methods for aircraft to report their state information like identity, position, and speed. Like other Mode S communications, ADS-B makes…
> aircraft surveillance has moved from controller-based interrogation to automatic broadcast I'd take issue with the phrasing "moved from" and would rather use "supplemented by". Controller-based interrogation is still widely used.
Moreover the advantage of Mode S radar (ground-initiated transactions) is that you're using a self-coherent system: the radar knows what it sent and what it is supposed to receive, and when, in a narrow beam, etc.
It makes lots of spoofing attacks unpractical. Where as relying on GNSS exposes to a whole bunch of 'constellation replay' or fake-adsb-telegrams attacks. Mode S lacks authentication, but there's no reason it couldn't be tacked on one day (through e.g. the already available 'advanced' data-link capabilities or the many available 'gicb' registers...). Even light session-authentication would break most of the remaining spoofing attacks (and most swap problems) on ground-initiated Mode S radar.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#13I'll save someone the googling since I just did. You need some hardware to hack: I think this is what you need: https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
Better also add a SAW bandpass and a properly designed amplification (LNA) stage to this. The RTL-SDRs are great - but heavily limited in their dynamics (8 Bit ADC). They get deaf quickly if you are located next to strong transmitters like FM/DAB/DVB-T/etc. Aliexpress has cheap antennas that include all of this.
Hey, mind looking up a link to one of those antennas? Just don’t want to pick the wrong part, so many abbreviations and acronyms.
I picked up an rtl sdr about a year or two ago and haven’t done much outside of listening to local FM stations.
Would be fun to go a bit deeper. Track satellites or listen to boats/ planes / etc.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#14Earlier quoted context omitted.
Better also add a SAW bandpass and a properly designed amplification (LNA) stage to this. The RTL-SDRs are great - but heavily limited in their dynamics (8 Bit ADC). They get deaf quickly if you are located next to strong transmitters like FM/DAB/DVB-T/etc. Aliexpress has cheap antennas that include all of this.
Hey, mind looking up a link to one of those antennas? Just don’t want to pick the wrong part, so many abbreviations and acronyms. I picked up an rtl sdr about a year or two ago and haven’t done much outside of listening to local FM stations. Would be fun to go a bit deeper. Track satellites or listen to boats/ planes / etc.
https://de.aliexpress.com/item/1005009311806479.html
Plus
https://de.aliexpress.com/item/1005009237905498.html
Maybe you can find an antenna with both integrated.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#15Also very interesting is the data which can be extracted from ADS-B. There have been several attempts from meterologists to extract wind data from through the actual and target direction values. Other sites use it to locate GPS-jammed areas because ADS-B can indicate when the reception fails (but still is able to transmit its position due to inertial fallback mechanisms).
Related: Some airliners directly transmit automated weather reports via either AMDAR or AIREP.
AMDAR: https://madis-data.ncep.noaa.gov/MadisAircraftPublic/
AIREP: Go to https://www.1800wxbrief.com/Website/interactiveMap, turn on the "Pilot Reports" layer, and look for "ARP" symbols on the map. You'll mostly see these over oceanic routes, especially in the Atlantic.
The AIREP reports are coded in PIREP format, so you'll need to look up the instructions for manually decoding those online.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#16I'll save someone the googling since I just did. You need some hardware to hack: I think this is what you need: https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
If you want an easy to use project to get a map and feed to different sites like adsbexchange and flightradar24, I would recommend checking out:
https://github.com/sdr-enthusiasts
https://github.com/sdr-enthusiasts/docker-adsb-ultrafeeder
https://github.com/sdr-enthusiasts/docker-flightradar24
https://adsb.im/home
There is a good community out there on github and discord that have flight tracking as a hobby. In addition to ADS-B there is also voice radio transmissions from aircraft (airband) and text messages (ACARS) etc. If you get hooked there is lots of different things to tinker with.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#17Also very interesting is the data which can be extracted from ADS-B. There have been several attempts from meterologists to extract wind data from through the actual and target direction values. Other sites use it to locate GPS-jammed areas because ADS-B can indicate when the reception fails (but still is able to transmit its position due to inertial fallback mechanisms).
Related: Some airliners directly transmit automated weather reports via either AMDAR or AIREP. AMDAR: https://madis-data.ncep.noaa.gov/MadisAircraftPublic/ AIREP: Go to https://www.1800wxbrief.com/Website/interactiveMap , turn on the "Pilot Reports" layer, and look for "ARP" symbols on the map. You'll mostly see these over oceanic routes, especially in the Atlantic. The AIREP reports are coded in PIREP format, so you…
That was a huge drama during Covid-19 as weather forecasters heavily rely on these automated weather reports for feeding their models. In Europe there are also special equipped Airbus/Boeings for collecting WMO-grade weather data while flying their standard routes - they were mostly grounded during the pandemic.
They partially replaced the data with the experimental Aeolus satellite which made its data into the productive forecasts within months due to their high quality.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#18The weather model based on ADS-B data was [very recently] discussed here: https://news.ycombinator.com/item?id=44734515 The article linked to this book, which is very comprehensive.
I've decided to check if it's possible to generate temperature and wind maps in real-time.
Temperature: https://adsb.exposed/?dataset=Planes&zoom=5&lat=45.8124&lng=...
Wind direction (Europe mainly): https://adsb.exposed/?dataset=Planes&zoom=5&lat=46.8734&lng=...
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#19I'll save someone the googling since I just did. You need some hardware to hack: I think this is what you need: https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
For optimal ADS-B reception, pair that RTL-SDR with a 1090MHz bandpass filter and place your antenna outdoors with clear sky view, as these signals are line-of-sight and easily attenuated by buildings.
Re: The 1090 Megahertz Riddle: A Guide to Decoding Mode S and ADS-B Signals
#20Section 1.2 reads:
>The concept of PSR is fairly simple. It is a rotating radio transponder with an omnidirectional antenna.
Shouldn't it be a directional antenna?