Height above sea level question re horizon

[eliot]

try this site - I use it to work out the theoretical distance a plane could be away from my adsb antenna - which is around 250 miles.

https://www.heywhatsthat.com/

10,000ft and 30,000ft:

Edited by eliot on Monday 13th May 20:21

[silverfoxcc]

Gents

Many thanks for all the replies, esp off-again, but when my son saw that he said.. He could have also said for the same reply..I'f it is cloudy.'...lol..and yes it was hypothetical, hence the reference to a humungus telescope

Plus its good to know that my M101 has come in useful
and what a cracking photo

The main reason for him asking is that we live just under the turning point for Heathrow arrivals for 09 from Europe and US and when they are anything from 3-5000ft the early sun give good lighting on the starboard side as they turn

..

[Wacky Racer]

I took this with a cheap £50 camera, no tele lens, The Isle of Man from near Ravenglass Cumbria,,,65 miles.

[paolow]

I hope it's ok - I dont want to derail the thread - but this seemed the right place to ask a question that has bugged me for ages?

Paolow Palace is 44m ASL and in Eastbourne. I have a sea view and on a VERY clear day I can make out the power station buildings at Dungeness (with a telescope obviously).

Previous links have suggested that the maximum view is a shade over 14 miles, yet the point to point distance is 31.5 miles - so what I am seeing is impossible no?

If I can find an image Ill show you what I mean....

[Tango13]

paolow said:

I hope it's ok - I dont want to derail the thread - but this seemed the right place to ask a question that has bugged me for ages?

Paolow Palace is 44m ASL and in Eastbourne. I have a sea view and on a VERY clear day I can make out the power station buildings at Dungeness (with a telescope obviously).

Previous links have suggested that the maximum view is a shade over 14 miles, yet the point to point distance is 31.5 miles - so what I am seeing is impossible no?

If I can find an image Ill show you what I mean....

Sounds possible.

Cheating quite a bit but if you stand on the roof of Boston Pilgrim hospital you can see Lincoln Cathedral some 27miles distant with the naked eye.

[paolow]

Tango13 said:

Sounds possible.

Cheating quite a bit but if you stand on the roof of Boston Pilgrim hospital you can see Lincoln Cathedral some 27miles distant with the naked eye.

Thanks - I tried and failed in my search for the 'best' photo I achieved - but you can see hastings (in some focus) and beyond there is a headland that reaches past it upon which a building or buiildings can be made out (rectangular man made structures anyway). I cant think what else they might be but at least it seems my sanity hasnt slipped completely away.
It does have to be an exceptional day though - and the right time of day at that...

[hidetheelephants]

paolow said:

I hope it's ok - I dont want to derail the thread - but this seemed the right place to ask a question that has bugged me for ages?

Paolow Palace is 44m ASL and in Eastbourne. I have a sea view and on a VERY clear day I can make out the power station buildings at Dungeness (with a telescope obviously).

Previous links have suggested that the maximum view is a shade over 14 miles, yet the point to point distance is 31.5 miles - so what I am seeing is impossible no?

If I can find an image Ill show you what I mean....

An AGR reactor building is ~60m tall and turbine halls maybe 25m, the site itself is probably about ~6m above sea level, geometry suggests the distance from the top of the reactor building to you is ~23 miles, but it's not; it's possible that what you're seeing is a mirage. Maybe try and photograph the telescope image with your phone.

[DoctorX]

Always found this website fascinating. Shame it’s not updated anymore and many links are dead. Still, some of the theoretical views are impressive. E.g. Snowdon from Scotland.

https://viewfinderpanoramas.org/panoramas/UPL/MERR...

The Cheviot in Northumberland is a dead link but recall theoretical views to the mountains of Scotland to the north and the Yorkshire moors to the south.

[Timothy Bucktu]

Drone shot at 120 Meters height in Chesham, Bucks...you can clearly see Canary Wharf aprox 30 miles away.

Photo by Leigh Richardson © courtesy of Facebook

[ATG]

I was on Aran Fawddwy a couple of weeks ago and you could clearly see all the mountains in mid and North Wales ... e.g. the Snowdon group, Arenigs, Berwyns, Harlech dome, Cadair Idris, and to the East and South you could see the Wrekin (at Telford), the Malverns and Brecon Beacons. The Malverns are about 90 miles distant.

Makes a change as the visibility on the Arans is often about 10ft.

[Snow and Rocks]

DoctorX said:

Always found this website fascinating. Shame it’s not updated anymore and many links are dead. Still, some of the theoretical views are impressive. E.g. Snowdon from Scotland.

This one still works and automatically generates panoramas marked with visible high points for anywhere you choose.

https://www.udeuschle.de/panoramas/makepanoramas_e...

Many years ago while doing my Geology degree I spent a few months mapping out Beinn Eighe in Torridon, with many nights spent summit camping in a tent on my own. Early one morning, while eating breakfast on the 1010m summit during a spell under a sparklingly clear Arctic airstream I spotted what seemed to be very distant cliffs beyond what were clearly the Outer Hebrides. They could only have been the cliffs of Saint Kilda - the highest in the UK and some 120 miles away.

I also remember some chat on a long gone Scottish hillwalking forum about a photograph taken on a long lens from the summit of Britain's 2nd highest mountain Ben Macdui in Aberdeenshire. The photo was out over the North Sea and clearly showed what appeared to be mountains, the shape of which matched a particular range in Norway. Even from that height this shouldn't be possible but apparently under certain high pressure conditions, the air can bend the light making views over huge distances possible.

[DoctorX]

[paolow]

hidetheelephants said:

An AGR reactor building is ~60m tall and turbine halls maybe 25m, the site itself is probably about ~6m above sea level, geometry suggests the distance from the top of the reactor building to you is ~23 miles, but it's not; it's possible that what you're seeing is a mirage. Maybe try and photograph the telescope image with your phone.

Ok - here goes - not my photo - but thats the wide view. I do have telescope pics - but annoyingly I cannot find the one I am looking for. Effectively it is a grey block though through a lens - so not much to look at - but Ill see if I can remember what I did with it.

I should add that the headland on the left is surely Hastings, so, with nothing else geographically possible that can only be Dungeness? Though I did think the distance made this effectively imposible - yet there it is?

Edited by paolow on Tuesday 14th May 09:50

[Tim330]

View of London from Ceasers Camp (581ft above sea level) between Fleet and Aldershot which google maps shows as 38 miles to Canary Wharf.

[Claret m]

Studying for my airline pilots license 40 years ago, VHF radio is line of sight. The formula we used was the square root of the height of aircraft times 1.25.

So 201 miles, so yes you are correct.

[paolow]

paolow said:

hidetheelephants said:

An AGR reactor building is ~60m tall and turbine halls maybe 25m, the site itself is probably about ~6m above sea level, geometry suggests the distance from the top of the reactor building to you is ~23 miles, but it's not; it's possible that what you're seeing is a mirage. Maybe try and photograph the telescope image with your phone.

Ok - here goes - not my photo - but thats the wide view. I do have telescope pics - but annoyingly I cannot find the one I am looking for. Effectively it is a grey block though through a lens - so not much to look at - but Ill see if I can remember what I did with it.

I should add that the headland on the left is surely Hastings, so, with nothing else geographically possible that can only be Dungeness? Though I did think the distance made this effectively imposible - yet there it is?

Edited by paolow on Tuesday 14th May 09:50

Update: As you asked I spotted the buildings were visible yesterday to got out my telescope and this is what you have:

[hidetheelephants]

Definitely the power station and you should not be able to see it, so it's likely an atmospheric effect as described above, a form of mirage.

[LordLoveLength]

When the ISS goes over on a clear night you can see it till it disappears at which point it’s well over Poland!
Bit higher than a plane mind…