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Evening Star Celestial Navigation (Jupiter and Polaris) Sight Reduction from a Tall Ship 

Practical Navigator
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We are underway aboard the 134 foot tall ship Corwith Cramer, and we take evening star observations of Jupiter and Polaris with a sextant, and then we do all the math to reduce them to a fix using the techniques of celestial navigation.
Two quick notes: the watch time was actually 20 seconds fast, not slow, sorry for mis-stating that. The math is correct though. And I skip the GHA increments for Polaris since I'm just looking for a quick and dirty whole number of LHA.

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14 июн 2023

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Комментарии : 27   
@MtnFlyer
@MtnFlyer Год назад
Thanks for posting again, Chris. I started learning celestial nav (from your videos) last year when I was trying to understand how WW II aircrews used the stars to navigate over the ocean. You make things very clear and accessible--and fun. I bought a sextant and an almanac and took some sun shots at different times from my yard in Colorado, and went through the equations to get a fix. Turns out my house is right where the realtor said it is. I think the neighbors were concerned, but a little apprehensive about approaching a guy walking around his property looking through a sextant at the sun, 800 miles from the nearest ocean :) Thanks again!
@marinoadventures8802
@marinoadventures8802 Год назад
You are truly a genius in navigation chris. I really love your videos. You are amazing! 🇵🇭
@hemeoncn
@hemeoncn Год назад
Great video, thanks. Brought me back to my navy days in the RCN when I was doing this.
@user-yn3ic5ru9i
@user-yn3ic5ru9i 5 месяцев назад
Another great video. I'm not sure why I took so long to subscribe to this channel.
@n6mz
@n6mz Год назад
1:50 Excellent video, thank you!! My (hardback) HO229 set is one of my prized possessions
@lyingcat9022
@lyingcat9022 Год назад
Ahoy Chris, fellow Service Member! You taught me everything about Celestial Navigation many years ago:) I’ve come back and watched your series a couple times over the years. Still the best lessons on RU-vid. I’ve since studied Bowditch 2019 relatively deep. But it is pretty dense and technical so without your base knowledge I would really struggled to understand everything. Thank you and it almost forgives you being Coast Guard ;)
@NavigationTraining
@NavigationTraining Год назад
Thanks LyingCat! Safe sailing :)
@paulatwood8467
@paulatwood8467 Год назад
Hi Chris, your CelNav videos are fantastic, congratulations 👍🏻. I was confused in this one though when you subtracted your “slow” watch error to correct the sight times. I thought that you added “slow” watch error and subtracted “fast” watch error. If I’ve misunderstood this please accept my apologies.
@NavigationTraining
@NavigationTraining Год назад
No you're correct I mis-wrote that sorry. The math part is right but I should have said "fast", my bad! Thanks for letting me know, I'll make a note for others about that :)
@lyingcat9022
@lyingcat9022 Год назад
Oh and I like to use the sight reduction form in The American Practical Navigator 2019 edition… aka The Bowditch. The PDF is still available free online. Volume 1: Part 3: Celestial Navigation Chapter 19: Sight Reduction Page: 319 Great reference and reminders of the basic procedures and definitions of all the tabular data/form entries. Hope this helps someone:) Happy Navigating
@bones1225
@bones1225 Год назад
Ta Chris,loads of fun to keep refreshed. Keep them coming.👍🏻
@marcg1686
@marcg1686 Год назад
Hi Chris, always great to see you uploading celnav content. Let's see how long it takes for the flat earthers to emerge from under their rocks.
@NavigationTraining
@NavigationTraining Год назад
Thank you! I'm gonna feel really dumb if it turns out that the world is actually flat lol.
@wesleyburghardt7189
@wesleyburghardt7189 Год назад
Getting fussy… do you need an increment also for GHA of Aries before computing LHA Aries? Or, does this not matter too much when using the Polaris tables to get latitude?
@marsa7600
@marsa7600 Год назад
@@NavigationTraining Don't worry, will never happen. Unlike them, we have knowledge, experience, and expertise in this field.
@marsa7600
@marsa7600 Год назад
@@NavigationTraining I mean, look back at the concepts used in celestial navigation. The celestial sphere, celestial poles, declination, and longitude are basically latitude and longitude but are used to determine the coordinates of a celestial body on the celestial sphere. All of this is impossible on a flat earth. Flat Earth can't have two celestial poles - because they don't have a south pole in the first place. So where is 90 degrees latitude S over a plane? Another thing, the south celestial pole is right at your zenith if you stay at 90 S. They should feel dumb for rejecting everything we know today, but they are too shameless to understand why they are wrong. It's actually called dunning kruger.
@NavigationTraining
@NavigationTraining Год назад
Hi Wesley you're definitely correct you can add the increment for GHA for Aries too. It won't make a huge difference but I skipped that part moving too quickly. Thanks for letting me know I'll make a note for others :)
@RyanParrishphoto
@RyanParrishphoto Год назад
Thanks Chris for the education
@babotond
@babotond Месяц назад
"..if you believe in that sort of thing..." 😂😂
@marcg1686
@marcg1686 Год назад
Hi Chris, I couldn't help but notice that you're still using your steam punk calculator.😊 I have taken the liberty of reducing the Jupiter sight using a Casio fx -300ES +. Great display and nice input syntax. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-r1vpziK-wwE.html
@NavigationTraining
@NavigationTraining Год назад
Nicely done, I just checked it out :)
@marcg1686
@marcg1686 Год назад
@@NavigationTraining Thanks for dropping by. I've watched your complete sight reduction video at least a dozen times. At least. It's the one video that ties the sight reduction process together better than any other.
@protothad837
@protothad837 10 месяцев назад
Another great video. I'm not sure why I took so long to subscribe to this channel.
@marcg1686
@marcg1686 10 месяцев назад
Hi Thad.👍