autonomous systems and navigation
I haven't posted to this forum before as I'm not flight crew so a few words of introduction needed. I am an ex FAA qualified dispatcher and a physicist by training - my day job these days is protecting GNSS based navigation systems from threats (RF interference, spoofing (fake signals) and cyber-attack) - I have more than 15 years experience of this (my dispatcher days were on older aircraft types- Viscount, DC9 and L1011 principally)
Interesting to follow some of the arguments on this site. I believe that fully autonomous aircraft are coming, although not in the near future. We do already have autonomous trains (Docklands light railway and Copenhagen Metro are two examples that I know of ). What is also true is that it's a bit easier to provide back up navigation systems to trains in the event that GNSS is not available (masking, underground, RF interference, etc) than for a transport system that does not use fixed tracks.
From a navigation point of view there are challenges to fully autonomous systems - firstly its the case that GNSS probably has to be a part of the overall control system as a common, precise time frame will be required (some of us call this 4D-trajectory management). But GNSS signals as received on the Earth's surface are very weak and thus susceptible to RF interference and from spoofing which could be carried out using a faked replica of a GNSS signal. Obviously this would be of great concern to anyone stepping onto an autonomous aircraft - what happens to the navigation system if a hacker can utilise the GPS channel to inject false or corrupted navigation messages or to report a false position.
Without enough robustness to defend or at least detect and revert to back-up navigation systems, this becomes a major issue.
In the GNSS industry, one of the fathers of GPS, Bradford Parkinson, talks about Protecting, Toughening and Augmenting GNSS. This means that for safety critical applications there is a need to do several things to harden GPS against attack (or unintentional effects):-
Protection through legislation that means if someone uses a jamming device ( and we believe that there are a lot out there in use on the roads today - just type in "GPS jammer" into google to find out how easy it is to get one) there are severe penalties in force to deter their use.
Toughening is about making sure that the GNSS Receiver or sensor has adequate detection and mitigation implemented ( Receiver Autonomous Integrity Monitoring (RAIM) is one of the techniques employed on today's aviation Receivers). This will need improvements to the way RAIM is implemented and advanced detection mechanisms (such as monitoring the automatic gain control of the receiver).
Augmentation is about using a back up system intelligently (INS is a very good bet here as essentially it is a very good dead-reckoning system and will get even better when cold-atom INS technology arrives that will need less fixes from GPS.
My point is that there is still a lot of work to do before we get to the point where our navigation systems can use GNSS and backups safely in a fully autonomous system - and it is an evolving situation - the bad guys will still try to defeat the protection mechanisms whatever industry does.
However, having said all that - autonomous transport is coming. My bet is that we will see autonomous cargo ships first - a lot of work is being done in that area. Ground vehicles and aircraft will follow - it's inevitable as a lot of industry money is being spent in these areas. But the timeline? May not come in my lifetime or in the timeline of most of the flight crew on this forum, especially when it comes to passenger carrying aircraft.
Autonomous systems will have to prove they are safer than ones with human control and that will take a very long time as the transport industry with safety critical concerns is thankfully cautious and conservative about adopting new and unproven technology. It will be a revolution but if it comes about in my lifetime I will still hanker after seeing (from jumpseat) skilled professional flight crew handling the DC9 in bad weather and with minimum automatics.