Astrocompass Mk.II: Tools for Northern Navigation

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Күн бұрын

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Near the poles, both magnetic compasses and gyrocompasses become increasingly inaccurate due to the converging of the earth's magnetic field and lines of longitude. Before the advent of electronic navigation aids, pilots operating at these high latitudes relied on specialized instruments like the Astrocompass, which uses the position of various celestial objects to determine the bearing of True North.
SOURCES:
www.mijnoudespulletjes.nl/pdf/...
www.prc68.com/I/AC_D500.shtml
www.samwallermuseum.ca/collec...
www.pge.com/includes/docs/pdf...
g4osj.co.uk/Text/Astro%20Comp...
www.sundials.co.za/THE%20SUND...
historyofbath.org/images/Bath...
www.radiomuseum.org/dsp_herst...

Пікірлер: 48

@HarryWHill-GA 8 ай бұрын

As a former practitioner of the dark and arcane art of celestial navigation, I understood you perfectly. I'm afraid that it went over most people's heads at 40,000 feet. Bravo Zulu (Well Done). Keep up the good work.

@stephenbritton9297 5 ай бұрын

I think he explained the concepts better than my C-NAV professor at the Maritime Academy did!

@nickjohnson410 8 ай бұрын

I'm convinced that this is the best history/engineering channel on YT and is purposely suppressed to give other channels a chance at existence.

@maxpayne2574 6 ай бұрын

This only appeals to a limited audience. The algorithm just delivers what a viewer is likely to want.

@cocotoni1977 8 ай бұрын

The astrocompass in planes would typically be used with the Air Almanac, not with the Nautical Almanac. The planes would carry the Air Almanac (or the pages relevant to days of the flight) in the cockpit for navigation already, there would be no need for them to separately carry the Nautical Almanac.

@doug18d50 8 ай бұрын

Had not thought of that. Thank you.

@StringerNews1 8 ай бұрын

2024 will be the year of the astrocompass.

@someonespadre 8 ай бұрын

Much of the western 2/3rds of the United States was surveyed using solar transits after magnetic compasses were found to be insufficiently accurate particularly in areas with local attraction due to high mineral content in the ground.

@carlthor91 8 ай бұрын

We have an old Lamb Air Norseman, on a pedestal, on the way to the Thompson airport, Thompson MB. Company I used to work for, had a Astrocompass mounted in it's 727, for it's flights from Canada to the Northern Russian Oil Patch.

@WillN2Go1 8 ай бұрын

Good video, thank you. I really appreciate the understanding and the clarity of your presentation. As a long time star watcher, but at a star party I won't be the guy who knows all that much. One thing I can say is that almost anywhere I have been in the world I can recognize Polaris the North Star even if I'm in a new latitude (like 7 months ago in Vietnam), planets are usually easy, and some other stars like Spica, Vega, Arcturus - but only if I can see a lot of stars or if I identified it the day before at about the same time. I also just sailed across the North Pacific. We had good weather, but I did not see the North Star, the Dippers etc even once in over a month. Only a few areas vertical and a bit to the south. Of course aviation would be above the clouds, but not always in the 1930s to 1950s in unpressurized prop planes. I just can't imagine flying blind. I once flew along the St Lawrence using AM radio stations as 'beacons.'

@ChrisAthanas 8 ай бұрын

These shorts are so great

@jeffdroog 8 ай бұрын

I appreciate the videos.The speed you're getting these out at is incredible.Keep up the great work man.

@EastBayFlipper 8 ай бұрын

I absolutely love your videos. Thank you so much because the level of effort is evident. I have a WW2 Canadian Tanker Compass, heavy little thing and oil/glycerin filled 3 cover and prism that pop up for very accurate bearings. Dad used it for hunting and surveys of our land with surveyor verification. 😉👍

@jasonarcher7268 8 ай бұрын

Your channel is phenomenal. The rifle grenade video got my subscription, but i love the variety.

@R.Lennartz 8 ай бұрын

Haven't watched your videos in a while to be honest, but I'm happy to see the channel seems to have grown quite a lot since last time I checked in, you certainly deserve it, your work has been of excellent quality for years.

@fredblonder7850 8 ай бұрын

Sooooo, it’s a really fancy and general-purpose sundial. There is a famous incident during the Cuban Missile Crisis, where a US Air Force pilot was sent on a classified mission in the far north, but east of Siberia, to collect air samples in order to see if the Soviets had been conducting atmospheric nuclear tests. He was navigating by the stars, but the Aurora Borealis was exceptionally bright that night, so he accidentally wandered into Soviet Airspace and nearly started an incident that could have started a war. Under guidance from his home base, he returned to US airspace, but ran out of fuel before reaching a proper runway. He made a mediocre landing in a snowbank, and was relatively uninjured.

@skivvy3565 8 ай бұрын

Love your work as always. Interesting use of danse macabre as an intro lol

@joest23 8 ай бұрын

This is fascinating and well explained. Terrific work.

@JoniFili 8 ай бұрын

Love the 10 min videos. Great choice of timming

@peterrenn6341 4 ай бұрын

I have my father's astrocompass which he kept as a souvenir of his National Service in the RAF (late1950s or so). Must dig it out and see if I can align it with some celestial body 🙂

@thomaslewandowski2504 8 ай бұрын

I really enjoy your videos, the subject matter is great and how you present it is fun and informative!! Keep up the good work!! Tom L Buffalo, NY

@kaitlyn__L 8 ай бұрын

The part you mentioned about reverse-deriving what celestial body you were even looking at reminds me of using smartphone astronomy apps, pointing the phone at a particular bright point in the sky and seeing which ones it could be. But, yk, with a book instead of software doing all the cross-referencing for me.

@doug18d50 8 ай бұрын

Am curious about the consideration of flying altitude of the aircraft while using the Mark II/IIa. Height/altitude above the surface of the ocean or elevation of land are important refinements of position finding when using the standard sextant, so should be a factor in using the Astrocompass, as well.

@CanadianMacGyver 8 ай бұрын

What you are referring to is the Dip Error, and none of the astrocompass manuals I have found take this into consideration. However, as I cover in the video, the observed body doesn't need to alight precisely with the sights; it can sit slightly above or below them. This suggests that the declination doesn't need to be that precise, since ultimately you are measuring the body's azimuth and not its altitude as you would when determining latitude using a sextant.

@doug18d50 8 ай бұрын

@@CanadianMacGyver Thanks! I've had the US version of the Astrocompass for several years, with the intention of adapting it for land vehicle navigation, by installing a pipe mount outside the vehicle. With the possibility of solar flare or deliberate EMP in mind, the Astrocompass should work fine unless the Earth does a Velikovski-Auchinschloss type pole shift. Came across a suncompass of British Army issue from WW2 for desert land navigation during the daylight hours. That would be a nice adjunct for the Astrocompass.

@amithhegde7753 8 ай бұрын

@@doug18d50 woww youre really thinking about all the variables... I admire you good sir.

@kallewirsch2263 6 ай бұрын

When using a sextant, you need to take this effect into account, because you measure the angle in relation to your physical horizon. In this astrocompass you don't need to take this height drop into account, because you create a "virtual horizon" by adjusting the whole instrument with the level bubbles. As long as those bubbles are centered, your whole instrument is set up in a way, such that 0° corresponds to a plane perfectly perpendicular to the earth axis (minus some small error of course due to the bubbles not being perfect). Also: Don't forget that this device is not meant to be used to determine your position but to give you the direction to geographical north. With a sextant, the determination of the position is crucial but here you already know your position (although you could use it in reverse to figure out your position with less precision) So why the same principle is not used with a sextant? Well, some sextants have bubble levels. But they are of much less use, since a ship is almost always rolling side to side, front to bottom. It is much easier to simply have multiple attempts at determining the height angle in relation to the visible horizon and adjust the Alhidade in small increments until it becomes perfect with the next rolling of the ship and adjusting for the known height drop.

@pauldogon2578 8 ай бұрын

I had one for the Shackleton

@frankodo3251 7 ай бұрын

I found this channel by accident when looking for some brain food on rifle grenades. And I was hooked immediately. The depth of knowledge, the presentation, the sense of humor and also the voice that makes listening easy. I’m an engineer by trade myself and know how challenging it can be to explain more complex matters to ppl without any background in engineering. But you make it look easy. One of my favorite channels nowadays, no matter the actual topic.

@Ed_Stuckey 8 ай бұрын

Thank you.

@Allan_aka_RocKITEman 8 ай бұрын

Starting at about 08:05 in this video: Specifically YOUR EYES are going to have a BAD DAY...😉

@mikemullenix6956 7 ай бұрын

I own 2 of these and use them to track the sun for solar panels. However, my units have very radioactive illuminating sights.those sight are some of the most radioactive items I have in my collection. I am concerned about that. Thank you for the video

@christophernewbury7444 8 ай бұрын

Got one!

@jessestanhope5404 3 ай бұрын

I have some questions for you pertaining to witch compass I have. I have the original box but the serial numbers aren't anywhere to be found. Please reach out if you have the time. Thank you!

@Jonno-5 16 күн бұрын

I have 2 of these things,in there respective boxes in almost mint condition. They never see the light of day.

@PooFIy 8 ай бұрын

Cool

@bobthecomputerguy 8 ай бұрын

As for casual navigation at night, thank god for the North star when you can see it.

@WilliamHarbert69 8 ай бұрын

I’ve got one too.

@comentedonakeyboard 8 ай бұрын

I asume at this age the radioactivity has faded away (just with the luminosity)

@fraserhopewell 7 ай бұрын

Radium has a half-life of nearly 1600 years, so although the phosphorescent compound that was being exited by the radium to give off light is burnt out, the paint is still nearly as radioactive as the day it was made. Old radium paint should be treated with respect, as you certainly don't want to be ingesting/inhaling it!

@battleangel5595 8 ай бұрын

Huh. Radium. While sneakers are technically not a device there were Converse All Stars sneakers that glowed in the dark back in the 80's. Had a pair of them and LOVED them. Wore them every day for almost 2 years. Also had a radium glow in the dark watch, Mickey Mouse Alarm Clock, and some random Japanese cat holding a trumpet clock that also glowed in the dark. I am aware of the radiation that surrounds us. I work in healthcare IT and have chosen to carry around a dosimeter made in Ukraine. It sips battery power like NOTHING else I've seen. Been a year since i bought it. Only down one battery bar with four to go. As to why I carry one... I work in the basement of a building that offers radiation treatment for cancer. And have to occasionally go to areas where X-Rays are taken. She also reacts to hot rocks (Gamma) surprisingly quick. So if the poo were to hit the fan and dribble down to my area I'd be alerted to higher levels, alert the IT basement dwellers, and scoot right quick.

@malcolmmoy 8 ай бұрын

All this plus getting it level while bouncing around at 25,000 feet, freezing cold and no doubt a bit terrified your about to be shot out of the sky, we owe so much.