WWII U.S. ARMY AIR FORCE TRAINING FILM " CELESTIAL NAVIGATION " FILM GREENWICH MERIDIAN 42314

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Official War Department Training Film. Restricted. 1- 204. Produced by The Signal Corps, in collaboration with The Chief of Air Corps. Celestial Navigation. Position Finding on the Earth. This 1940s era, black and white film covers the complex but straightforward calculations a navigator needs to determine his position on the earth and how to use celestial objects to do so. The film opens with a man tracking star charts. An animation shows the Earth and points to its different zeniths and geographical positions 1:16. If the bodies geographical position on the Earth is known then its meridian is also known, as shown in this animation 1:40. Using the Greenwich meridian which is the zero meridian for longitude, the Greenwich hour angle can be measured, it is the angle at the pole between the meridian and the celestial body on the Greenwich meridian. It is measured to the West through 360° 2:07. Another type of hour angle is shown. It is the angle at the pole between the observer’s meridian and the meridian of the celestial body 2:23. It is also called the Local Hour Angle or LHA 2:38. The Air Almanac is consulted 2:50. Navigator determines his longitude 3:03. The Greenwich hour angle of a celestial body represents the longitude of its geographical position 3:12. Greenwich hour angles and local hour angles are calculated 3:39. Zenith distance is calculated. It is the measurement between the geographical position to the observers position 4:05. The angle from the line through the center of the earth to the observers Zenith is always 90° as this animation shows 4:23. Animated starlight hits the earth at an angle 4:40. In this particular case the angle of the starlight is 60° making the Zenith distance measurement 30° or a complement of the altitude 5:00. 90° minus the altitude always equals the Zenith distance 5:05. Linear value of the Zenith distance is calculated 5:20. The circle of position is demonstrated 5:40. Military man uses a navigational aid 5:53. The pole represents a star and in order to see the top of the star at the same angle from any direction you need to stay on the circumference of the circle 6:15. If the radius is lengthened, the angle of observation is decreased 6:32. If the radius is shortened, the altitude is increased 6:44. The circle of position is measured once again 7:05. A star’s altitude is measured from the circle of position 7:27. The navigator’s circle of position can be measured with another circle of position, creating 2 intersecting points. One may be disregarded and the other on track with his dead reckoning 8:00. A globe is shown 8:15. The navigator uses minute circles of position called lines of position (LP) as this animation shows 8:33. A third line of position based on a third celestial body may be added to get an additional check 8:50. The American Practical Navigator is consulted 8:53. The astronomical triangle is shown 9:00. Mathematical equations for the triangle fill the screen 9:28. Solving the triangle is now quite simple, filling out forms with precomputed data 9:55. A man fills out the form and does the math for the astronomical triangle 10:15. The navigator starts with an assumed position - the dead reckoning position - or, it might be a position on either side of the dead reckoning position 10:48. The navigator determines local hour angle 11:00. Algorithmic tables are consulted 11:15. Navigator finds his position by using an intercept in determining his actual position 12:11. Actual position and assumed positions are compared by determining the observer’s altitude 12:20. A review of the measurements covered in the film, focusing on circle of position and line of position 13:05. Books of tables are displayed 13:23. Navigator consult his books and his maps 13:37. End of Training Film. 1 - 204.
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Пікірлер: 78

  • @reloda
    @reloda2 жыл бұрын

    Ahh, that clears that up then.. no more getting lost for me!

  • @wes326
    @wes32621 күн бұрын

    I was an Air Force RC-135 navigator back in the 80-90s. Celestial navigation works well in good flight conditions. When away from land we had to shoot cell every 20 minutes, makes for a long day. We also used grid navigation (heading reference) when in polar regions. Very easy to make data extraction and computational mistakes.

  • @apostolosnikolaou8667
    @apostolosnikolaou8667Ай бұрын

    Hats off! Amazing patient and skills. I would have throw it out of the window 10 times!

  • @cherifbar
    @cherifbarАй бұрын

    In the old days they had pilots, navigators, radio operators and flight engineers. It is amazing how technology has reduced that to just two persons in the flight deck. With AI, one day airplanes will fly autonomously much like trams connecting terminals at airports.

  • @alexroman730
    @alexroman7302 жыл бұрын

    Absolutely love this

  • @PDZ1122
    @PDZ11222 жыл бұрын

    Children of the Magenta Line, take heed!

  • @wrightmf
    @wrightmf3 жыл бұрын

    Interesting, I may look further into this and try to compute my location just to get a feel for how it was done. I was thinking some nav guys could do this quickly and accurately. Though need to locate books with tables. I have used log tables back in 1970s when calculators were making their debut. And I learned how to interpolate. I remember at that time I got a 7th place log tables, a US GPO book from the 1930s, big thick and small print as there were a lot of numbers. Obviously very dated. It is long gone but I read such books were produced when govt hired out of work mathematicians to compute 7th place log tables and trig tables. This later paid off during Manhattan Project where many did lots of calculations requiring high precision.

  • @goognamgoognw6637

    @goognamgoognw6637

    3 жыл бұрын

    It's amazing to think they had no computer or even calculators and were using books table for transcendental functions. They must have been very sharp and clear thinkers, not swamped and clouded by overuse of computer graphics.

  • @justincase5272

    @justincase5272

    3 жыл бұрын

    @@goognamgoognw6637 : Thank you. Your assessment of my having been a "very sharp and clear thinker" is much appreciated! - USAF Navigator, B-52H and C-130E, 1989-2009, Retired.

  • @goognamgoognw6637

    @goognamgoognw6637

    3 жыл бұрын

    @@justincase5272 Given your service dates my compliment did not apply to you. I said : before the age of computers and calculators. Any reasonably vigilant dumbass can use a computer. So you're getting a kick in the rear instead for trying to steal a compliment not addressed to you.

  • @Somethingisntright64

    @Somethingisntright64

    2 жыл бұрын

    @@justincase5272 There are very few certified flight navigators left in the USA. The last count was around 49 certified on record with the FAA. It’s a shame that no one can get a rating for it because no one teaches the course anymore and we cannot locate anyone with examining authority. The rating may not be needed with today’s GPS, however, it sure is an interesting subject matter that few can master and many would like to learn.

  • @warreneckels4945

    @warreneckels4945

    2 жыл бұрын

    @@Somethingisntright64 We may have to relearn it soon. Russia tested a missile that destroys satellites. Disabling GPS would make it harder for our armed forces to navigate. At least we will not have to worry about log tables to seven digits.

  • @johnmorykwas2343
    @johnmorykwas23432 жыл бұрын

    Glad I learned this in Nav School at 'Mother'. Pilots did not have the intelligence level to learns such a complicated aviation tool. That's why pilots go where Navs tell him to go. Pilots are the chauffeur.

  • @PDZ1122
    @PDZ11222 жыл бұрын

    Or if in doubt, put your squadron number on the compass and fly that heading to get home.

  • @saugeyes
    @saugeyes3 жыл бұрын

    Dont forget to keep an eye on cyl. Head temp and manifold pressure at the same time. Hopefully you calculate correctly so you know if you need to throw all extra weight overboard depending on the amount of fuel you have to get where you're going.

  • @eddievhfan1984

    @eddievhfan1984

    2 жыл бұрын

    The USAAF wasn't in the business of doing solo flights over the Atlantic. These navigators would be providing course info to the pilots they worked for, not flying the plane directly. (Though some autopilot systems from this era could have their heading controlled remotely by the navigator)

  • @blessedwithchallenges9917

    @blessedwithchallenges9917

    2 жыл бұрын

    Tell that to Amilia Erhard...

  • @johnmorykwas2343

    @johnmorykwas2343

    2 жыл бұрын

    That's the copilot's job.

  • @Paul-ou1rx

    @Paul-ou1rx

    2 жыл бұрын

    Draw straws or just get volunteered?

  • @user-uc7jd7os2s
    @user-uc7jd7os2s14 күн бұрын

    And Slide Rules in aircraft engine development! 🤓

  • @maureenogorman8740
    @maureenogorman8740Ай бұрын

    Route recalculating

  • @joeguzman3558
    @joeguzman3558 Жыл бұрын

    That's one of the first things we have to learn as boy scouts, I'm sure today most people won't find their way out if not for cellphones

  • @viperdriver82
    @viperdriver822 жыл бұрын

    This shit is complicated

  • @MagnumOpusSRT
    @MagnumOpusSRT2 жыл бұрын

    I should not watch this while drinking.

  • @anthonyw9129
    @anthonyw91293 жыл бұрын

    But what about flat Earth ?

  • @goognamgoognw6637

    @goognamgoognw6637

    3 жыл бұрын

    Yes, we know you understood absolutely nothing in that video.

  • @tiberiu_nicolae

    @tiberiu_nicolae

    3 жыл бұрын

    That's an inferior model to be honest... too many holes

  • @anthonyw9129

    @anthonyw9129

    3 жыл бұрын

    @@tiberiu_nicolae I know I was being sarcastic

  • @justincase5272

    @justincase5272

    3 жыл бұрын

    @@tiberiu_nicolae : Just one, but it's a doozy, and the Earth sits in the middle.

  • @Paul-ou1rx

    @Paul-ou1rx

    2 жыл бұрын

    Just use binoculars to find familiar landmarks in every direction. If you hit the ice wall, you've gone too far.

  • @TheDieselbutterfly
    @TheDieselbutterfly2 жыл бұрын

    This is silly,all they had to do was to look at their cell phones

  • @razorjoe4729
    @razorjoe47292 жыл бұрын

    major issues, 1 the celestial sphere is an azimuth projection,, has nothing to do with earth, you are the center. You get the angle to the star, find true north, measure azimuth angle for position, with the time. Direction of heading and location 🤠 no toy globe needed

  • @iveneverseensuchbehaviorin5367

    @iveneverseensuchbehaviorin5367

    Жыл бұрын

    Except the geometry is based off star light being parallel, bye bye flat earth. Celestial sphere not celestial plane.

  • @humanidadeparalela4572
    @humanidadeparalela4572 Жыл бұрын

    FLAT EARTH!!

  • @iveneverseensuchbehaviorin5367

    @iveneverseensuchbehaviorin5367

    Жыл бұрын

    Flat earth foiled by celestial navigation

  • @awatt

    @awatt

    11 ай бұрын

    FAT EARTH

  • @BillyBOB-sm3rl
    @BillyBOB-sm3rl2 жыл бұрын

    WOW, coodoos to navigators. Talk about booooring.

  • @jahsoncole
    @jahsoncole Жыл бұрын

    First words of this video: "To be useful to the aerial navigator, positions in the celestial sphere must be transferred to the earth." So, because we must maintain that earth is a globe we ignore the actual observation because for the earth to be a globe we have to invert it. The sky is flat¿

  • @marcg1686

    @marcg1686

    Жыл бұрын

    Let me guess, geometry was an opt-in subject and you decided to opt out. Correct?

  • @awatt

    @awatt

    11 ай бұрын

    Globe confirmed 💯🌎

  • @jahsoncole

    @jahsoncole

    11 ай бұрын

    Either the sky is flat or the earth is flat!! Is the "horizon" horizontal? According to your inverted math, the sky is flat...

  • @marcg1686

    @marcg1686

    11 ай бұрын

    We need the geographic position of the celestial body. That's how the intercept method works. Is this too difficult?

  • @hendo337
    @hendo337 Жыл бұрын

    What a crock, no navigator ever used a globe.

  • @iveneverseensuchbehaviorin5367

    @iveneverseensuchbehaviorin5367

    Жыл бұрын

    guess you didnt watch

  • @awatt

    @awatt

    11 ай бұрын

    kzread.info/dash/bejne/l3tmm6qrhZm5nNo.html I'll gust leave this here. Globe confirmed 💯🌎

  • @oNeGiAnTLiE
    @oNeGiAnTLiE3 жыл бұрын

    9 min in and no mention yet of North star? Lotta nonsense and talk about fake space tho... and zenith TVs I guess the sextant had been eliminated as well. Many sailors have been lost making such calculations on a "Globe" model. 👌👌👌 The Flight of the Navigator i suppose was one piloted by lost peoples

  • @goognamgoognw6637

    @goognamgoognw6637

    3 жыл бұрын

    This is apparently part of a series of videos on celestial navigation. Other concepts were probably introduced in previous videos.

  • @tiberiu_nicolae

    @tiberiu_nicolae

    3 жыл бұрын

    And many more sailors have fallen of the edge of the earth I suppose?

  • @marsa7600

    @marsa7600

    3 жыл бұрын

    @one giant lie for mankind. You're stupid. Long before GPS, navigators used a device called ‘sextant’ to determine the angle of a celestial body. From that data, the latitude of their current location can be determined. This can only happen if the Earth is spherical. In the Northern hemisphere, navigators usually used Polaris. Using a sextant, they measured the angle between Polaris and the horizon. The angle would be very close to the latitude of their current position. In the Southern hemisphere, they did the same thing but with the south celestial pole. The problem is that there’s no bright star close to the south celestial pole, unlike Polaris in the North. So, they used the nearby Crux and Pointer stars to determine the approximate location of the south celestial pole. The angle between the south celestial pole and the horizon is the same as the latitude of the observer. In the Northern hemisphere, the southern celestial pole is not visible. And conversely, in the Southern hemisphere, Polaris is not visible. So, there’s no ambiguity on which star to aim. Celestial navigation is possible only because the Earth is spherical. We make use of the knowledge of the correct figure of the Earth for the purposes of navigation. This is how our ancestors were able to travel to the other side of the world (and back to the original location) without the modern technology we have today.

  • @marsa7600

    @marsa7600

    3 жыл бұрын

    The angle (or altitude) to Polaris approximately corresponds to the latitude of the observer. This fact is observed on every location on Earth where Polaris is visible. By tracing the path to Polaris from multiple locations on the flat Earth model, the lines will not point to a consistent position of Polaris. The reason is that the Earth is a sphere and the flat Earth model does not represent reality. The position of Polaris today is conveniently very close to the north celestial pole. And therefore, the altitude or the angle between horizon and Polaris can be used to determine the approximate observer’s latitude. South of the equator, Polaris is not visible and obviously cannot be used for navigation. Polaris is below the horizon and obstructed by the Earth. It is necessary to locate the south celestial pole in the sky to determine the observer’s latitude. It is more difficult as there is no bright star nearby, unlike Polaris in the north. Polaris itself is not always the north star. Due to the Earth’s axial precession, the position of the north celestial pole will shift. Twenty centuries ago, the north celestial pole was closer to Kochab than Polaris. All the observed facts are only possible if the Earth is a sphere, and impossible to happen if the Earth were flat.

  • @marsa7600

    @marsa7600

    3 жыл бұрын

    "guess the sextant had been eliminated as well" wrong.