Long distance mirror signalling.
Вставка
- Опубліковано 24 сер 2018
- Long distance mirror signalling.
This video shows me signalling over twenty seven and a half miles (44 Kilometres) using a mirror in bright sunlight, the mirror was 13 inches by 10.5 inches (330mm X 254mm)
It takes an hour to drive from Aberporth to Aberystwyth following the coast road, it’s a distance of some 33.5 miles but the straight line distance is 27.5 miles over the sea.
I was at home near the village of Aberporth with the mirror and Carol, my wife’s best friend, was in Aberystwyth when she made the video for me.
I'm very grateful to Carol for taking the video as Sophie, my wife took a video at the same time but Sophie’s camera focused on the near distance where as Carol was able to get a usable video, in fact Carol emailed the video to us when she got back home to America.
There are a number of videos on UA-cam that show you the best way to use a signal mirror in a distressed situation but I couldn’t find any videos showing signalling over a long distance.
What I don’t show in this video is that I had a bamboo cane in the ground about 14 foot (4 meters) in front of me, I lined up the target area (Aberystwyth) with my eye and the top of the cane and then with the mirror where my eye was. I flashed the mirror such that sunlight hit the top of the cane and subsequently over to Aberystwyth. In other words, I couldn’t see where the light was been directed but by seeing the light hitting the top of the pole I knew I was getting it right. Emergency signal mirrors have a hole in the middle so as you can line up the target. I did try using the shinny surface of a CD/DVD but the girls couldn’t see it over that distance but they probably could have if they had binoculars.
Over 27 miles the difference between someone in Aberystwyth acutely seeing the reflection or missing it down to an extremely narrow angle of error.
Many that’s to Carol, as I said I’ve wanted to see this since I was about 7 years old.
Kind Regards . . . Andy - Наука та технологія
I just came across your video. I have to say 27 1/2 miles is insane. I mean the condition's were right but still, wow. You just made me realize I need to add one of these to my EDC
Hi Andy. Hope you are fine and healthy. Great to see a video by you. Of course I would look forward to more.
Good One
Wow, 27 miles. I'm new here to the channel after watching your RF alignment of the Eddistone receiver. Now subscribed. 73 MM0SDK
Great to see you back . Have enjoyed all of your videos , particularly from your work related stuff . Best wishes and keep well .
Thanks for the kind words. Regards . . Andy
glad to see you again, always enjoy your vid.
Thanks Dennis . . Andy.
Hi Andy, Great to see you back!
Thanks Will, just been too busy having fun.All the best . . Andy
We are very happy to see you back Andy.
Thanks Peter, man I've just been too busy having fun to be making videos for UA-cam but it's nice to have such a good response for my efforts. All the very best . . . Andy
I'm very glad to see a post of yours. I found your channel some time ago and watched a lot of your videos. Then I noticed you stopped posting. Now this is a happy surprise. Please keep this channel active, you have a lot to teach.
Thanks for that, I have a lovely project coming up, we're building a house of our own design but it's in such a prominent position as soon as it was on air everyone would know where we were and I don't really want that. Part of me would love to share the experience of things like designing the grounding for the lightening conductors and steel frame but I don't want visitors turning up out of the blue. All the best and thanks again. . . Andy
@@AndyDaviesByTheSea Yeah, I can understand that. I also consider privacy and peace as rights and necessities. Well, of you post anything, technical, memories, interesting stuff, I'll be glad to watch, and I believe some other people will too. I just saw your new post, I'll watch it right now. Thanks!
Cool ... !!!
Thanks for sharing .
Interesting indeed.
Interesting video Andy... thanks for sharing. Best regards.
Thanks Ron
27.5 miles! Wow very cool
I bet it goes further with a larger mirror too.
It sure would.
Well hello, nice to know your feet are still on the ground and not under it! Hope your well and are going to do lots more radio videos.
Best regards,Carl,G0lka.
I love your videos! I'm thinking of trying to get my ham license soon. They don't require morse anymore.
Lucky you, I took me 18 months to crack the code, I'm dyslectic and it's a pain. I spoke to an American girl who said,. . . 'I struggled learning the code, it took me all night.' It turned out that she was a cello player and cloud read and write music. I think that the ability to read and write music conditions the mind for morse code. (or maybe as my teachers said, I'm just thick.) All the best and good luck with the exam. . . Andy
Looks nice and flat ;)
thank u very much
Nice to see you again Andy.
Warships also use light-signals, sometimes better then radios.
Greetings from the Netherlands!
Part of me would like to build a laser transmitter/receiver to play with as I'll have a house in both places but I'd probably get into trouble zapping seagulls down along the way. All the best . . . Andy
The German used in WW2 an system that worked with light for communication. See the video:
ua-cam.com/video/KS_t8DR9r7E/v-deo.html
Thanks for the link Ben, man I could very easily get
distracted and start making optical transmitters. I wonder if the light is
modulated before the audio is added. The first time I saw optically generated
sound was on the 35mm film that I saw when I was a cinema projectionist back in
the mid 1960’s at the ABC Cinema Selly Oak Birmingham, England. I think I’ve
still got an old light dependant resistor from a Westrex sound head from those
days, the resistor was activated by an exciter lamp and lens arrangement. I
also think I still have a few frames of 35mm film in an old wallet somewhere.
Thanks again for the link. Regards . . .
Andy
Very interesting to see this work over such a distance Andy. I did some experiments with a standard small signalling mirror - the type which has a central hole, but also has a mesh with glass retroreflecting beads - (you can look up the patent from about WW2) you get a bright image of the sun on the mesh, which you then move over the sighting hole - you are then definitely pushing the beam at your sighted direction - I have only managed about 500 metres though - using a red reflector (retroref. type, so angle not critical) on a tree 250m away, which worked well. Your test here is much more significant though. If I remember correctly - the size of the sun's image at the observer is roughly the distance divided by 100 - which would be 440m diameter in your test - it's scanning past rather fast as you move the mirror of course !
Cheers, Dave (also in Wales)
Hi Dave I did try a DVD but the girls couldn't see it but I'll bet they could have if they had had binoculars. Regards . . . Andy
Yes I read that in the description Andy - I haven't tried a dvd or a cd, but I suspect that neither is reflective enough - too much light is scattered by the 'track pits' I think - dvds do make a very good spectroscope using a cardboard tube though - I have tried this myself :o)
Interesting thanks for uploading.
Thanks Fred . . Andy
How large was the heliograph you used? Was it glass, plastic, or steel?
I see you've produced a few videos recently. Thought you found another hobby to occupy your time. I spotted a comment you gave to ham on you tube using your channel handle about purchasing property and have plans for full wavelength dipoles. Thought to check whether you've made any new videos and found that you have indeed. I see from the comments that there are a couple us that missed your videos too. We get busy when we retire. I am sure that has caught on to you now. Look forward to seeing more videos as you have the time. Would like to find you on HF but you work phone and i work CW, although, when contesting with my club lately I have picked up the phone when CW has been quiet. To see the face of my club friends when they saw me with a microphone in my hand instead of key is priceless. Hi
I learned Morse with a flashlight for a merit badge in Boy Scouts but I barely passed. I forgot the light/Morse signalling in short time. Learning CW by ear was much easier before taking the Novice (USA) Amateur Radio test in 1973 and again in 1985. While stationed at Guantanamo Bay, Cuba and aboard ship in the U.S. Navy I was issued a mirror of the type noakeswalker describes. Glad I never had to use it. I never received training for its use.
Hi Terry you're right, talk about getting busy when you retire! Yep I've just got my hands on the field at the bottom of our back garden which I've been trying to get for 18 years, rotten timing though as we've just started to build a house up in Aberystwyth (were this video was taken) it's taken a year to buy the place and another year to design the house that we want. So yes I guess you could say the new hobby has been learning how to use the 3D drawing package SketchUp (free from Goole but very powerful and extremely useful) and designing and drawing the house from scratch. Lots of sleepless night some from being excited about it all and some from the anxiety about 'are-we-doing-the-right-thing' They tell me at my age I ought to be sat by the fire with my slippers on and a nice cup of tea, not building an upside-down house at the top of a bloody great hill. In my mind I'm about 20 or 30 . . . and I'm loving every minute.
All the best . . . Andy
Long story short what is the elevation of observer(s) and of mirror(s)?Coordinates of sites.
Hey Andy, Good to see you're still knocking about :) Amazing that it could be seen it from that far! I would have thought that earth's curvature would have it beyond the horizon at that point.
I thought that I'd answered this once but I can't see it here. I was 120 metres above sea level and the girls were about 20 metres above sea level. regards . . . Andy
Cool
I watched those movies as well, and always thought it was just Hollywood and would never work. How did you get the reflection on target (this was always my doubt about the westerns)?
I put a bit of a description in the box under the video but have a look at some of the UA-cam videos about mirror signaling. You need to have something to sight on between your eye and the target so that you can see that you're pointing the sun in the right direction. . . . Andy
OK, hands up, I didn't expand the description - that explains it. Well done for getting it to work at all. I wonder if the standard sort of hole-in-the-mirror-with-fixed-sight sighting device could really work at anything over about a mile. Of course, with a telescopic sighting device mounted centrally in the mirror, and very accurately calibrated, then anything would be possible. I don't know what the spread of your beam was, can't have been much for it to have been visible through all the haze. A wild guess is that by the time it arrived at the camera it might have been 20' in diameter? So a fantastic bit of bamboo cane adjustment - I really wouldn't fancy trying to position the top of 1/4" diameter pole accurately in line with, say, a house, at 27 miles distance. Many thanks for a very interesting and unusual video.
Hey, it was just happenstance that where I set myself up on the deck with the mirror it just happened that the bamboo bean poles in the vegetable bed where perfectly in line with the target. But I don't think it would be hard to achieve good accuracy if you have some sort of pole or stick 4 or 5 metres away from the mirror in line with the target that you flash the sunlight onto. It was a bit of fun but maybe next time I'll get someone at the other end to reciprocate. Ho, I forgot to say that I did have a 2 foot long tube about 1 inch diameter to use as a sighting tube (no lenses just looked through the hole) and I had 4 little flags each about 1 inch square spaced out from the tube by about 4 inches. (at 3, 6, 9 and 12 o'clock) the flags were at the far end, the idea was if I lined up the target down the tube then with the center of the mirror at the back end of the tube, when the flags were illuminated the light must be hitting the target. when by chance I saw the bean pole was in the right place I didn't bother with my sight tube as the greater distance to the pole would be far more accurate. . . . Andy
Hi nice vid but as a kid I made a circle of polished stainless steel both sides put a 3mm to 5mm hole in the middle. How to use it look at your target through the hole and then look on reversed side of steel at your face find the tiny sunspot on your face and alter the angle of mirror till the spot gose into the hole.
This then puts the sun reflected on the target I got incredible distance with this disc size about 100 mm 4 inches try it as I did have some interesting flashers
When I first left school I worked as a cinema projectionist and the Chief Projectionist gave me an old mirror out of the back of and arc light from a 35mm cinema projector. It was from what's called a 'Peerless arc' lamp it was about 18 or 20 inches diameter, concave, with a hole in the center. I remember poking a broomstick through the hole to the focal point and burning the end off it when I pointed it to the sun. I can't remember what the heck I did with that mirror or where it is now, I do remember burning all sorts of things with it including my hands! Happy days .. . . Andy
what about at night if you had a full moon would it work
Well as daft as it sounds I guess you could always see the reflection of the moon in a mirror with the aid of binoculars, but it probably wouldn't cover a long distance. You could set up a series of mirrors around the world so that you could 'import' sunlight around the curvature of the earth or better still simply ask NASA to paint the Aitken basin silver, (it's the biggest crater on the moon) that way we'd have a bit more light at night. It's a big problem and probably the reason we invented the phone system. All the very best . . Andy
So earth is flat??
Not quite, the mirror was at about 120 feet above sea level and the camera was at about thirty or forty feet above sea level. But you can bee sure that the light beam was pretty straight. But having said that gravity can bend light a little. (don't ask how much, you'll have to look that up)
All the best. . . Andy
At 20 miles the object in the distance should be hidden by 264 feet of curvature
Yes and at 27 miles almost 500 feet of curvature LOL. Ballers crack me up.
flat earthers: it all depends on how high above sea level the observer and mirror are. Observations should be made at an elevation where line of sight is at least 25 feet above sea level. With observer 25 feet above sea level and mirror 500 feet above sea level at 27 miles distance line of sight is just 25 feet above sea level. Refraction shouldn’t hinder visibility on a calm, clear sunny day
Water is level. . With mirror signaling you can prove the earth is flat. Run the same test from shore to shore. If the earth was a globe, curvature would prevent you from seeing the reflection
Yes and at 27 miles almost 500 feet of curvature LOL. Ballers crack me up.