[HN Gopher] FlightAware Map Design
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FlightAware Map Design
Author : marklit
Score : 89 points
Date : 2025-10-27 11:42 UTC (6 days ago)
(HTM) web link (andywoodruff.com)
(TXT) w3m dump (andywoodruff.com)
| theguitarman wrote:
| A concern I have for modern day mapping systems is that digital
| maps, like Google Maps and OpenStreetMap (OSM), typically operate
| on the assumption of a static, rigid Earth. I don't know much
| about it, but from what I understand, they use coordinate systems
| like WGS84, which are a snapshot in time. These would be great
| for local precision but less so for tectonic precision, due to
| tectonic plate activity (continental drift), post-glacial rebound
| (areas still rising after ice sheets melted), and sudden seismic
| events (earthquakes).
|
| And then there's GPS coordinate shift. From what I read, ITRF,
| ETRS89, and coordinates associated with epoch dates attempt to
| deal with this.
|
| So, even though it may not matter as much for FlightAware maps,
| autonomous and GPS-based systems are a little worrying. Being
| overly dependent on them may have some be risk over time.
| marklit wrote:
| I'm having a hard time tracking down the OSM-specific actions
| around this but Australia moved 1.8M back in 2017 due to
| continental shifting https://www.ga.gov.au/news/news-
| archive/australia-officially...
|
| The Airport in Tartu, Estonia had a navigation upgrade last
| year in order to help mitigate navigation jamming that's taking
| place in the region. https://www.eans.ee/en/uudised/tanasest-
| saab-tartu-lennuvalj...
|
| Defcon had a great talk on all the different navigational
| systems pilots can use and a note at the end that these
| shouldn't be decommissioned at the rate they're experiencing
| atm https://www.youtube.com/watch?v=wSVdfOn737o
| phoronixrly wrote:
| OSM is a community of predominantly amateurs/enthusiasts who
| trace uncorrected satellite photos and store the data as WGS-84
| coordinates with 7-digit precision.
|
| The point I'm trying to make is that there are more important
| sources of error before you get to tectonic movement and GPS
| drift... And OSM is plenty useful even without outstanding
| precision.
| hdgvhicv wrote:
| Whenever I've done things on OSM it's based on gps recorded
| tracks - no doubt not particularly accurate but there are
| many overlaid ones which average out to be fairly precise
| (1mish) for the purpose.
| phoronixrly wrote:
| Oh yeah, I forgot about the enthusiasts that use
| uncorrected GPS positioning with low-cost hardware. One
| meter precision at the very best of conditions...
| cyberax wrote:
| OSM uses a hundred nanodegrees as the grid resolution (
| https://github.com/openstreetmap/OSM-
| binary/blob/32c3e921665... ). It gives a bit more than 1cm
| precision.
|
| > The point I'm trying to make is that there are more
| important sources of error before you get to tectonic
| movement and GPS drift...
|
| You can absolutely measure tectonic drift on the OSM maps!
| They've existed long enough for it to be actually significant
| in a lot of places if you download the old data.
|
| This also comes up all the time when trying to overlap data
| from local agencies onto the OSM maps. You end up with parcel
| boundaries visibly off.
| phoronixrly wrote:
| > OSM uses a hundred nanodegrees as the grid resolution
|
| As I said, 7-digit precision.
|
| > You can absolutely measure tectonic drift on the OSM
| maps! They've existed long enough for it to be actually
| significant in a lot of places if you download the old
| data. > > This also comes up all the time when trying to
| overlap data from local agencies onto the OSM maps. You end
| up with parcel boundaries visibly off.
|
| Yeah, assuming the person who added the features you're
| observing as 'visibly off' did not use 1-meter Bing imagery
| with a 10-meter offset...
| ericpauley wrote:
| This is not the correct way to count digit precision,
| which should be independent of the units used. If there
| were 360,000 degrees in a circle would this same
| precision suddenly be 4 digits? If we measured in radians
| would the digit precision become 9? Of course not...
|
| Given the 100ndeg precision is across the full earth,
| this would be 1 part per 3.6 billion or 9.5ish digits of
| precision. The location of the decimal point when
| displaying it is irrelevant.
| willtemperley wrote:
| What also needs to be taken into account is that real
| world longitudinal distance changes by the cosine of
| latitude. 1 degree of longitude is 111km at the equator
| and 19km at 80 degrees.
|
| In GIS the gold standard for positional accuracy is the
| Root Mean Square Error, measured in real world distance
| units.
| cyberax wrote:
| This is a real problem for applications that need to deal with
| precise locations. For example, if you want to estimate the
| roof sizes using the aerial imagery and the LIDAR point clouds
| (e.g. the one from the USGS:
| https://usgs.entwine.io/data/view.html?r=%22https://s3-us-we...
| ).
|
| The coordinates do not align precisely in many locations,
| exactly because of the actual motion of the Earth's surface.
| Tectonic plates, aquifer depletion, land sliding down the
| mountain slopes, etc. For practical applications, there are
| steps in the data processing to fit the different datasets
| together ("registering" one of them). As long as you have
| timestamped maps, you can reasonably reconstruct the current
| WGS84 coordinates by fitting the data together.
| defrost wrote:
| As geodetic problems go, though, this is trivial small beer
| stuff compared to, say, stitching together magnetic maps
| measured on different days or gathered in flight in different
| flight directions, or normalising continental scale
| radiometric datasets gathered across decades.
|
| Modern digital post WGS84 mapping is a breeze compared to the
| days of dealing with chains under tension and stitching
| together across differing ellipsoids and datums.
| jvvw wrote:
| For a while I worked on a project related to mapping the
| ancient world (so you could e.g. click on a ancient city and
| then see items from museums from that city, references in
| ancient texts etc) and one of the interesting problems was not
| just that cities changed over time but that things like
| coastlines also did.
| efskap wrote:
| Sounds super compelling, did it end up launching?
| willtemperley wrote:
| > These would be great for local precision but less so for
| tectonic precision, due to tectonic plate activity (continental
| drift), post-glacial rebound (areas still rising after ice
| sheets melted), and sudden seismic events (earthquakes).
|
| This is exactly what 4D deformation models are for:
|
| https://proj.org/en/stable/operations/transformations/defmod...
| bytefish wrote:
| It's great to see Apache Baremaps being mentioned. It's a great
| project and I saw its first iterations. Really amazing they have
| built a community around it.
|
| Although my library in Apache Baremaps probably plays a minor
| role only (PgBulkInsert for Postgres COPY protocol), it's great
| to see it chugging on all this data day by day.
| timenotwasted wrote:
| I had an opportunity to work with OSM data (nowhere close to
| something like FlightAware would need) at the beginning of the
| year and this comment put into words something I felt deeply at
| that time -- "OSM is amazing, but as a global project with
| thousands of contributors, its data can be... quirky.". I have
| tons respect for this kind of stuff after working on that project
| and seeing the massive amount of time that gets invested to make
| things look correct for the use. It's the quintessential if
| nobody notices then you've done your job extremely well.
| decimalenough wrote:
| I flew United a few days ago and noticed the change in the flight
| map: you can now see individual aircraft moving about airports,
| which is awesome. What's less awesome is that the marker of the
| aircraft you're most interested in, namely the one you're sitting
| on, is not aligned with the map when in detailed view, and unlike
| the Flightaware app, you can't get info about other airplanes
| (operator, flight number, destination, etc) by tapping on them.
|
| Even more annoyingly, during takeoff and landing, the flight map
| system _intentionally_ disables any way to see your precise
| location, altitude, velocity and direction. The "cockpit view"
| pane that shows these when cruising becomes unavailable, and the
| airplane marker is also hidden beyond a certain zoom level.
| Presumably this is some kind of misguided security by obscurity
| measure to stop terrorists, who apparently aren't smart enough to
| carry mobile phones with GPS receivers.
| alberth wrote:
| (2024)
| sitzkrieg wrote:
| O/T but flightaware leaked users data for years and tried to get
| away with not letting anyone know, use anything else.
| adsbexchange is better in every way
| echoangle wrote:
| I also prefer adsb exchange. But one thing other flight
| tracking apps are better at is displaying departure and
| destination airports of commercial flights.
| amelius wrote:
| Where can I see a heatmap of how many flights went over in the
| last 24 hours?
| ilikepi wrote:
| This may interest you: https://adsb.exposed/
|
| Discussion: https://news.ycombinator.com/item?id=39990346
| amelius wrote:
| Looks pretty, but I have difficulty pinning my location on
| the map and seeing how many flights actually went over in the
| last 24h.
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