Peter wrote:
In fact you need only 1 DME to get position!How does that work?
How does that work if you fly an arc around the DME?
Any future DME would have to offer more than simple distance to a station. In an ideal world it would be a unit capable of simultaneously accessing two or more DME stations, to make this a flexible navigation system the unit would require a database.
It follows that the DME should be able to access the GPS database and present position data using the equipment currently presenting the GPS information. This will not be a panel mount unit but one that will be remote mounted and controlled via software presented on the GPS or the ND. It would also have a lock function for use during approach .
It would be my guess that the reason we have yet to see a DME from Garmin is the KN 62/63/64 range (& KR87 ADF ) had been developed by Gary Burrell before he left King avionics to set up Garmin and he saw little advantage in duplicating what is a very reliable unit…… so he just made sure that Garmin Avionics were compatible with the King DME & ADF.
As GPS jamming and spoofing are now real dangers the market needs a reliable alternative navigation system be that DME or eLORAN.
GPS is a problem. From browsing through the official strategy document (for Norway), there are two main issues for civilian aviation.
The solution is to keep traditional navigation systems as fully functional “backup” as long as they last and it’s an economical option. By the looks of it (from Avinor visual approach carts) this results in more DMEs and less NDBs and VORs.
The main direction is still GPS though. But there are other stuff going on also. Last year Avinor finished their network with over 200 WAM stations. It’s normal operational mode is with GPS (standalone or with ADS-B), but it will also operate without any GPS. WAM needs very precise timing, which is cheap and easy to get with GPS. Without GPS, atomic clocks are needed, which is being installed now. WAM/ADS-B is not a navigational system, but with ADS-B-in it certainly could be used as such for GA also without GPS. As a GA pilot today, with an old mode C transponder, I’m only a radio call away to know my exact position, even without radar or GPS.
However, googling this stuff I found another slightly disconcerting thing. In Norway there has never been any focus on mode-S. For GA transponder is optional, but mode C is required in controlled airspace wherever/whenever ATC say it is. The aviation authorities together with Avinor and the met office has plans to make ADS-B mandatory in all controlled airspace from 2030 already. The disconcerting part is that the GA community as a whole would welcome this, due to all the upsides as online weather and a standard traffic information system system for everyone (not the jungle it is today). This will also include drones. There will be close to zero opposition to it, and therefore it will be implemented.
