25th June, ie end of this week, and the UK will no longer be guaranteed the EGNOS satellite based augmentation system that improves the accuracy of your GPS signal.

Some airfields had LPV approaches that could be used down to 250’ in bad weather. These will no longer be available. The main airports will continue to use their ILS approach aids, most of which can be used for fully automated landings in zero viz and zero cloud-base anyway. The smaller airfields will have to limit operations to slightly higher descent altitudes than the LPV approaches allowed.

Disappointing, but probably not a deal-breaker.

I’m not sure about the post 25th accuracy of the typical sat-nav positioning. It will be less accurate and we might notice it on a 1/25,000 OS map, but probably not in the typical car sat-nav.

Is this because we left the EU?

Basically, we had the option of paying the EU a contribution towards maintaining EGNOS. I’m not sighted as to the reason(s) that we decided to do without.

Anyway, it’s a fait-a complete. The US and North America have their WAAS and Europe, including Norway, Switzerland etc have EGNOS. We have opted out.

We previously put a lot of effort and expertise into this augmentation system. I’m surprised we have decided to follow this course of action.

It affects me slightly in the air. Not so sure yet about when out hiking etc. But the old map and Silva compass still work, even without a battery :sunglasses:

Ah - I see. Such a good idea to leave the EU, we’re so much better off now…

Well, not exactly. We have (had) a choice, as we do with many things, regardless of other directions that we chose to take.

There was talk of us putting up our own SBAS satellites, but I’ve not heard anything specific in that regard for the past couple of years.

Anyway, my aim was to alert us all to the possibility of a (slightly ?) degraded accuracy in our Sat-Navs as of Friday !

Anything with WAAS/EGNOS enabled/incorporated, will be less accurate in the UK. Whether it will be important, depends on how accurate you need to know your position.

How does that work Don? If the satnav in my phone/car has WAAS/EGNOS enabled chipset, surely it’ll keep working?

Hi Eoink. You could well be right.

The EGNOS codes that are available for civilian use, are free to use, just like WAAS (in the US) and GPS (worldwide). So far as I know, the two UK located RIMS (Glasgow and Swanick) will still be functional so the system’s accuracy, integrity, availability etc won’t change.

However, the EGNOS Working Agreement with air navigation service providers will cease, and with it the guarantee that the overlay system is fully functional. The UK CAA won’t accept the use of such a system.

Whether the associated risk is real or significant, i’m not sure. If it isn’t real, then our car and i-pad sat-navs will still be reliably very accurate.

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