* How to Operate an Airport in Antarctica (also via flightradar24.com): https://news.ycombinator.com/item?id=26340384 (68 comments)
* Nuclear Power at McMurdo Station, Antarctica: https://news.ycombinator.com/item?id=27549484 (192 comments)
And perhaps my favorite blog, brr.fyi makes frequent appearances here. An example:
* South Pole Water Infrastructure: https://news.ycombinator.com/item?id=40615530 (63 comments)
For all Antarctica posts: https://brr.fyi/tags#south-pole
The ground based equipment dictates approach path with no updates to onboard approach databases on aircraft needed.
RNAV can’t do curved approaches on a glide slope as far as I know.
ILS minimums are generally slightly lower than LPV which is the RNAV approach type with lowest minimums.
This supports older aircraft with ILS (localizer with glide slope) that don’t have a WAAS capable GPS.
Edit: Also, using the Mode S transponder with precision approach radar instead of ADSB-out for the aircraft position means older planes without ADSB (because they don’t fly under a mode C veil) can be supported and it also means the base is trusting their equipment for the aircraft position rather than trusting an aircraft that potentially doesn’t have an SBAS GPS on board.
That said, it’s always nice to have a ground-based alternative approach. I wonder if they have sustained issues with GPS this far south.
RNP approaches can, Monterey has one: https://aeronav.faa.gov/d-tpp/2408/00271RRZ28L.PDF
So ILS or MLS had the benefit of being able to provide better precision without things like realtime ionosphere monitoring and correction. TLS let's you use all sorts of augmentation mechanisms without modifying the aircraft too.
TLS seems much less vulnerable to spoofing, given the signal strengths involved.
The idea of an onboard TLS spoofer seems both feasible and very scary, though, now that I think about it...
Can this work at pole station too? I realize there's a lot of other considerations landing there in the winter (fuel freeze temp?) but the less isolated it becomes, the more science we can get.
I bet it's "quite exciting" to be a pilot trying to fly at the pole doing anything apart from flying straight and level right past.
Your longitude readout becomes useless as the lines of longitude converge. Your GPS altitude becomes wildly inaccurate because the orbital inclinations of the constellation means they never get above 45 degrees or so from the horizon. Your compass is pretty much trying to point straight down (and at the magnetic pole which is some way apart from the rotational axis of the earth pole).
And it's cold, likely very bad weather, the landscape make orienting yourself and even seeing upcoming mountains challenging, and you are a long long way from a safe landing spot and even further from any realistic help.
That said, magnetic compass deviations are common all over the world due to things like iron ore veins, so maps have corrections available.
GPS isn't used for altitude in aircraft in practice, it's too inprecise - barometric altimeter plus radar altimeter are the precise instruments for that.
I wonder how similar their ILS is to the ILS used on navy aircraft carriers?
The Instrument Carrier Landing System (ICLS) is basically just an upgraded version of the civilian ILS which they squashed down onto a ship. It broadcasts a beam of radio waves into the air and any aircraft can pick it up and follow the glide slope.
There is also the Automatic Carrier Landing System (ACLS), which is roughly equivalent to this system. Radar receivers on the carrier are fed into a computer, which calculates the aircraft's position and transmits back commands back to the aircraft's autopilot.
The cool part about this Transponder Landing System is that it doesn't require any equipment upgrades to the aircraft. An aircraft equiped with original ILS equipment from the 60s can use it.
https://wandereatwrite.com/how-i-got-paid-to-live-in-antarct...
Found this random paper that has more details
https://www.icasc.co/wp-content/uploads/2023/02/Application_...
https://www.usap.gov/sciencesupport/scienceplanningsummaries...
I would guess it to be pretty rare that multiple aircraft would be on approach at once, and if so, I'd imagine one could hold at a distance to allow approaches to be serialized.
I’m not sure how the TLS figures out what transponder to look at, I guess either the controller enters in the code of the plane on approach or there’s some reserved transponder code for the approach.
But neither WAAS nor GBAS are authenticated, so are ultimately both are spoofable.
We have to switch to "grid" north to make sense of directions there.
https://en.wikipedia.org/wiki/Universal_polar_stereographic_...
Problems start when you're moving around or doing trigonometry, though; following bearings starts getting weird even at otherwise negligible distances, for example, and runway designators on the opposite thresholds might not be exactly 180 degrees "apart".
But it's not like these effects don't exist everywhere on earth at some scale; they get gradually more pronounced the closer you get to the poles, so I'd be surprised if avionics software would get really confused by them.
Do you have a source for that? I was under the impression that INS-based navigation was much more precise than for that to have been an issue by the time GPS became available to civil aviation.
https://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007#Af....
The exact same error could have happened for a Pacific crossing near the equator. Magnetic aberration being larger near the poles had nothing to do with it.