True Anomaly vs. Mean Anomaly
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- Опубликовано: 26 авг 2024
- This video explains what the Mean Anomaly is, how it relates to the True Anomaly, and how to use the Mean Anomaly to propagate a simple 2-body orbit.
In case the links don't work within the video:
orbitnerd.com/b...
orbitnerd.com/b...
As promised, here are the scripts which will do the conversions between True Anomaly, Mean Anomaly, and Eccentric Anomaly: github.com/lba...
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
Thank you very much! why have you stopped?
What a shame only 3 videos were ever made.
What are you doing
Its a pity you stopped making videos. they are awesome and helped me a lot!
This is the simplest and best explanation of mean and true anomaly.
You know thoses videos are so usefull I use them as references since years each time I need a remainder ? Thank you.
This chanel probably isnt active anymore but if it is, I would love a walkthrough of the second long problem on the USAAAO NAO competition. Its about orbits!
3 hrs of web search and finally 6 min video and all done, thanks
link for the script is not working :(
can someone fix it, please?
Thanks I am taking orbital mechanics as a class, but I still feel that videos like these are the best way to learn the material.
Hey mate! Thanks for the video! Studying orbital mechanics at the moment in uni (Space Science) and your simple explanation and engaging drawings have helped me understand the concept so much better than my lecture has!
22 seconds in and just pausing at that picture I think I already get this more than I did through trying to read wikipedia!
Love this video! What a fantastic explanation. We actually played this for the class in orbital mechanics class.
Fantastic video, great job keeping the visuals up with the pace
Great video! Enlightening, comprehensible and somewhat funny too.
NEED MOAR VIDEOS CAUSE YOU ARE AWESOME. kthx
can anybody please say me while doing that problem how did he find out the Mean anomaly ?? i mean he wrote down the True anomaly and then he writes down Mean anomaly, and after that done with finding Mean anomaly at different positions how did he find out the True anomaly back again using the Mean anomaly at different positions ???
Your video was increadibly helpful!
I used a program called Octave. It's very similar to Matlab, but is available for free.
Thanks
Nice interesting video again. Very useful. but why aren't you making anymore videos?
Very helpful video, and good method of teaching. 😍💗
great video! needed to brush up on these terms for my solar system simulator.
BTW, why did you calculate mean anamoly three times?
what is the program you used to model the motion in 3:37 ?
If you had a gauge in a spaceship that could give you one of the anomalies in deg. which one would you choose in order to get best picture of your position in an eccentric orbit. I think certainly not mean anomaly coz that has nothing to do with position at all. Could you use something like Zenith angle/flight path angle istead. What about %/Orbital period or %/orbital distance (counting from Pe) that could give a good picture of position right?
Amazing explanation. Good job!
Thank you for your helpful videos!
fantastic visual. Thanks!
This was a very useful video! I wanted to grab the referenced scripts, but it looks like the website has expired.
Hi, all the links have stopped working. If you click on the links, you get a response that the Website and account have expired, but you could log in as a site owner....could you reactivate the side or place the resources online somewhere else? Please thank you very much! Greetings from Germany.
how do you convert from eccentric anomaly to true anomaly?
Thank You. - Lucy
concise
beautifully explained🌹
the link for conversions does not work
Good explation. a bit fast but good.
So how are you supposed to do the change in times to true anomaly at 5:30? It looks like the equations work one direction but stop working the other way (since eccentric anomaly is it two places in the equation I found and people say you need to do some brute force methods to get a solution)
You skipped the most important part!
EDIT - nevermind I created a guesser system in a spreadsheet where I guess E up to how ever many decimal points I want and then check the result against my eccentricity value to find how close they match. Once I reach 100.00000 whatever % match I stop.
I use this equation and stop once my eccentricity result sufficiently matches my actual eccentricity:
((M-Eguess)/-1)/sin(Eguess) = e
Probably will program this later in python lol
It was very helpful. You made it so easy ! Thankyou very much :)
I really loved it.
For people coming in late, in the example the value of the semi-major axis is 26500km.
Website expired...
Great video!
Great video, thanks!
I like your videos, keep them coming!
Appreciate for your helpful video dude !
Okay, so you can calculate the motion of a satellite around earth if you know the semi-major axis, the eccentricity and the current true anomaly. But what if I only have the current position and velocity vector of the sattelite, not knowing yet how the orbit is shaped? Is it possible to calculate all the orbital characterics of the sattelite from these two pieces of information?
+MyFavoriteDisease +OrbitNerd I'm looking for the same answer. With only the position, velocity, and the central mass, the shape of the orbit can be defined by first finding the specific orbital energy a specific relative angular momentum. However I do not know the equation to find the initial true anomaly.
Keep up the good work!
Gr8 explanation
great vid, please enrich your channel with more videos, subscribed .
No longer available man. Sorry... Can you help me out?
Links in the description doesn't work
great video! make more please! :)
The site expired D:
You somewhat brush over the fact that for M = E - esinE you cannot solve for E numerically - how did you do it?
you have got to iterate. Maybe have a look at www.agi.com/resources/educational-alliance-program/astro-primer/primer80.htm
How to do iteration
I like your video, Please make a new video
I dont get it... why call it a true anomaly when you can just call it angular position? Why complicate things?
To go from mean anomaly to eccentric anomaly, there is a simple formula:
M = E - e*sin(E)
You'll need to iterate a few times for an accurate answer.
how do you go from eccentric anomaly to true anomaly?
+Julia Zeng
θ=2*arctan(sqrt((1+e)/(1-e))*tan(E/2))
where θ is the true anomaly
e is the eccentricity
E is the eccentric anomaly
There are also expressions for this with sine and cosine functions, they're on Wikipedia
thanks!
Adriaan smit do you know how to do iteration any idea?
If the mean motion is in radians per second, and it is constant, couldn't you just divide the entire orbital path 2pi by the number of seconds in a year? Got completely lost at 5:00. Think the video was great to that point. But too much too quickly after that. How for example does one use the eccentric anomaly for the conversion and why
Jim Keller Not sure exactly what your question is pertaining to the mean motion. The main problem with using the mean motion is that it only directly correlates with the mean anomaly...you can't use it directly with either the eccentric or true anomalies. However, you'll want to know what the true anomaly is since it will tell you exactly where the object is within the orbit. You use the eccentric anomaly to convert back and forth between the mean and true anomalies.
Sorry about losing you at the 5:00 minute mark, that's where I do some hand waving and start showing you some calculations without the equations. If you have access to the book, I would suggest looking at the beginning of chapter 2 of Prussing & Conway that I mention in the video. The first few sections go into full details about converting between these anomalies. Barring that, look at the Wikipedia pages for mean, eccentric, and true anomalies...however, they don't fully explain how to determine the eccentric anomaly from the mean anomaly, this is a little tricky to do. Also, you can take a look at the scripts provided with the video. They'll provide all the equations needed, but don't provide the theory or explanations that Prussing & Conway would provide.
OrbitNerd Thank you so much for your response.
As for mean motion in radians couldn't you just take ωavg = 2πrad/1year (3.2×10^7 seconds in one year), to get angular velocity of 2.0×10-7 rad/s? Isn't this the same as nu = sqrt of mu/a^3 as you have above? pretty sure it works out the same.
MIN KUK E SÅ HÅÅÅRD, OMG
Tomorrow is my exam
man im gonna fail...
great video! needed to brush up on these terms for my solar system simulator.
BTW, why did you calculate mean anamoly three times?