Johanan Codona
Johanan Codona
  • Видео 72
  • Просмотров 51 032
The angular power spectrum of the solar crescent
The character of Solar Eclipse Shadow Bands are controlled by the shape of the near-totality solar crescent. I defined a parameter epsilon that describes the apparent relative sizes of the sun and moon. Negative epsilon are annular eclipses. Total eclipses have positive epsilons. The longer totality lasts, the larger the value of epsilon. This simulation shows crescents and their corresponding angular power spectra for an observer near the edge of the path of totality. For more info, see adsabs.harvard.edu/abs/1986A%26A...164..415C
Просмотров: 61

Видео

AOSim2 Simulation of a Bahtinov Mask with Focus Sweep
Просмотров 2897 лет назад
A Bahtinov (Бахтинов, Google Translate says "Bakhtinov") mask is a simple and elegant tool for focusing a telescope on a star. This simulation uses my AOSim2 software to create a simulated negative image of the diffraction pattern as the focus is swept. The defocus value is the signed rms wavefront error caused by defocus. For something that can be made out of construction paper and an X-Acto k...
Defocused Sirius @ 500fps minus mean. (Quality test)
Просмотров 1148 лет назад
This is the defocused Sirius data with the mean removed and the colorscale set from /- 1.5 max sigma. This makes it easier to see the structure. The large fast structure is from high altitude turbulence while the lower altitude turbulence is probably hundreds of meters away. The telescope is a 10" LX200 Classic. The camera is a Point Grey Flea3.
Defocused Sirius @ 500fps minus mean.
Просмотров 318 лет назад
This is the defocused Sirius data with the mean removed and the colorscale set from /- 1.5 max sigma. This makes it easier to see the structure. The large fast structure is from high altitude turbulence while the lower altitude turbulence is probably hundreds of meters away. The telescope is a 10" LX200 Classic. The camera is a Point Grey Flea3.
Defocused Vega at 15 fps with 10" SCT
Просмотров 2648 лет назад
This is made from 15 fps images of Vega (alpha Lyr) in a very defocused configuration. The starlight only passes through the corrector plate ant the primary and secondary mirrors before the the camera sensor. The telescope had been outside for less than an hour and the tube and secondary housings had not fully come to thermal equilibrium with the cool evening air. There is a lot of rapidly-chan...
Sirius at 500 fps with a 10" LX200 defocused in steps
Просмотров 2688 лет назад
This is a scintillation study. Sirius was imaged using a 10" Meade LX200 Classic f/6.3 SCT. The images were taken with a Point Grey Flea3 at 500 fps. Sirius was about 20 degrees above the horizon and rising. The 8-bit images were binned 3x3 for creating the video. The video scales are not optimal near focus, but were retained for consistency. The video is shown in negative gray scale for contra...
nlCWFS2 20150208 Red channels
Просмотров 869 лет назад
The red channel of the MMT nlCWFS experiment on Feb. 8, 2015. The cameras are listed in numerical order, but the optical order is: 1. Before the relayed pupil 2. After the pupil but beyond the linear curvature range as well as beyond the caustics. Still dominated by the pupil. 4. After the pupil at a range comparable (but not equal to) camera 1. 3. After the pupil where the Fresnel scale is get...
Defocused point source seen through 2 turbulent phase screens
Просмотров 2189 лет назад
This simulation also has a plane wave Fried length (r0) of 3 cm, but split between two Kolmogorov phase screens. The lambda=556 nm point source is observed from a distance of 5 km using a 10" Meade LX200. The light passes through two equal strength turbulent layers (Cn2=3.2e-12, thickness=1m), at 2km and 4km from the source. Both phase screens are moving across the line of sight with equal and ...
Simulation of a defocused point source with turbulent phase screen
Просмотров 3339 лет назад
A point source (lambda=556nm) illuminates a Kolmogorov phase screen at 2000m (r0=3 cm). It then propagates 3000 m further to a Meade LX 200. The telescope is defocused to a distance measured from the pupil back toward the source as the wind blows the turbulence past the line of sight. The left image is the complex field at the pupil of the telescope. The right image is the intensity after defoc...
Defocused scintillating streetlights
Просмотров 4369 лет назад
Everyone knows city lights twinkle, but I am studying the wealth of information they reveal when they are defocused. This video was taken using my 10" Meade LX200 (classic) F/6.3 and a Canon 60D. There is a car driving in the video near the end showing its headlights.
Defocused street lamps in strong scattering---longer movie
Просмотров 6510 лет назад
Movie of strongly scintillating sodium street lamps. The telescope is a Meade LX200 25.4 cm and the defocus was such that the Fresnel scale sqrt(lambda z) was about D/10 (-ish). The video was taken at 300 fps.
A distant set of defocused streetlamps in strong scattering
Просмотров 5410 лет назад
This experiment is to look at the the correlations between meta-pupils from different sources. I couldn't defocus too much before the meta-pupils would overlap, so the relative strength of the refractive modulation is different. The sodium light sources are about 4 miles away and the defocus was probably about 3 miles. The video is 60 fps, which does not resolve the flashing.
Distant Out-of-focus streetlamp in strong scattering
Просмотров 6210 лет назад
This is a simple experiment that has a very strange behavior. The sodium lamp is 3 or 4 miles away and my telescope was focused to about 1 or 2 miles. The video is taken at 300 fps with a Meade LX200. The middle scale is about where the blurring due to the intrinsic size of the streetlight matches the Fresnel scale sqrt(lambda z). The problem is very complicated, so I won't try to explain the t...
GMT Phase Apodization Coronagraph anti-halo modes
Просмотров 11210 лет назад
There anti-halo pupil field modes are used to create an apodizing phase plate (APP) for the GMT. The modes were computed including a complicated secondary support and ASM shadow pattern in the central segment. These are fake interferometric images for each mode, cycling through the scalar phase of the reference beam. For most of the best APP designs, I used about the first 120 anti-halo modes. ...
A max-diff dearth of Camelopardalids May 23-24, 2014
Просмотров 3210 лет назад
This is the same image data, processed differently. I used the difference between images taken 5 seconds apart to compute the maximum difference seen in 10 minutes. Had there actually been a meteor storm, this would have been very cool. I see lots of planes and satellites, one good sporadic meteor, and maybe some faint ones late in the video. The max-diff clouds at the end are very cool!
A dearth of Camelopardalids May 23-24, 2014
Просмотров 3710 лет назад
A dearth of Camelopardalids May 23-24, 2014
Lunar Eclipse 2014/4/14-15 from Tucson, AZ
Просмотров 3610 лет назад
Lunar Eclipse 2014/4/14-15 from Tucson, AZ
Nonlinear propagation of high-power laser radiation
Просмотров 62110 лет назад
Nonlinear propagation of high-power laser radiation
dOTF self-test of a Boston Micromachines 140-actuator DM.
Просмотров 10411 лет назад
dOTF self-test of a Boston Micromachines 140-actuator DM.
A Trip to the Moon: Lalo A. Codona and Kids 1966
Просмотров 19211 лет назад
A Trip to the Moon: Lalo A. Codona and Kids 1966
Festival of Light -- Caltech 1976 (part 2 of 2)
Просмотров 9511 лет назад
Festival of Light Caltech 1976 (part 2 of 2)
Festival of Light -- Caltech 1976 (part 1 of 2)
Просмотров 22011 лет назад
Festival of Light Caltech 1976 (part 1 of 2)
Microray simulation of scintillation beyond a pupil with Kolmogorov aberrations
Просмотров 15011 лет назад
Microray simulation of scintillation beyond a pupil with Kolmogorov aberrations
Caltech Glee Clubs: The God of Abraham Praise
Просмотров 4,3 тыс.11 лет назад
Caltech Glee Clubs: The God of Abraham Praise
The Complete Works of Wm. Shakespeare -- part 1/5
Просмотров 7011 лет назад
The Complete Works of Wm. Shakespeare part 1/5
The Complete Works of Wm. Shakespeare -- part 4/5
Просмотров 3411 лет назад
The Complete Works of Wm. Shakespeare part 4/5
The Complete Works of Wm. Shakespeare -- part 5/5
Просмотров 2411 лет назад
The Complete Works of Wm. Shakespeare part 5/5
The Complete Works of Wm. Shakespeare -- part 2/5
Просмотров 3411 лет назад
The Complete Works of Wm. Shakespeare part 2/5
The Complete Works of Wm. Shakespeare -- part 3/5
Просмотров 1811 лет назад
The Complete Works of Wm. Shakespeare part 3/5
Caltech Men's Glee Club: Dedication
Просмотров 12811 лет назад
Caltech Men's Glee Club: Dedication

Комментарии

  • @G7MIX
    @G7MIX 16 дней назад

    Bom video, gostei muito de ver seu conteúdo 👍👍

  • @robbiethepict2783
    @robbiethepict2783 5 месяцев назад

    I loved the Waltzers.

  • @craiginches
    @craiginches 10 месяцев назад

    Anyone remember the Rib Tickler.

  • @craiginches
    @craiginches 10 месяцев назад

    I loved going to the Codonas when I was a boy. It was magical to me. We called it the Carnivals.

  • @neilmcbeath954
    @neilmcbeath954 11 месяцев назад

    The last time I visited Aberdeen beach (May 2023) I was primarily struck by how desolate it had become. There seemed to be even less than there had been in the 1960s, and it was not that marvelous then.

  • @jamescadger3302
    @jamescadger3302 Год назад

    I remember the beach in the let 1960 and the 1970 i love going down to the beach when I was a young boy i still go down to this day but I has changed a lot it's a shame i just think of the good old days

  • @multiinuteis
    @multiinuteis Год назад

    Hey look like an eye! And also vibrations... u have more?

  • @dahnilama1417
    @dahnilama1417 3 года назад

    The bouncers were a bunch of pricks in the 90s.

  • @louisehosie8391
    @louisehosie8391 4 года назад

    Hi Johanan, I work for STV News - I'm looking to use part of the video here you've posted for a piece I'm doing about Codonas - can you please contact me on louise.hosie@stv.tv - thanks

  • @LarryBees
    @LarryBees 4 года назад

    great archive thanks I am new sub !!

  • @mirosaide8786
    @mirosaide8786 4 года назад

    Hi Johanan! I have been working on this kind of simulation and I need some kind of help regarding the phase screen.

  • @hazels4841
    @hazels4841 5 лет назад

    this makes it seem way better than it is

  • @treymixon3618
    @treymixon3618 5 лет назад

    Hi

  • @heyitzbecca
    @heyitzbecca 6 лет назад

    Who else remembers the ghost train? Lol that was epic and the crazy train I miss them both ❤️❤️😂

  • @MaddyAlexx
    @MaddyAlexx 6 лет назад

    Holy shayt

  • @fritzwilhelm8258
    @fritzwilhelm8258 7 лет назад

    Not Claire de Lune

  • @gamersmartmaster2637
    @gamersmartmaster2637 7 лет назад

    I'm at codonas

  • @nurn6487
    @nurn6487 7 лет назад

    Why thick phase screen?

  • @wolfendoom7269
    @wolfendoom7269 7 лет назад

    Jesus codonas has changed so much over the years

    • @TheJenrichichi
      @TheJenrichichi 7 лет назад

      I am about to go back after having lived there in the 80's - don't even recognise the beach and Codona's now!

  • @jlcodona
    @jlcodona 8 лет назад

    Focusing at infinity (i.e. at the star) does not reveal the wind structure. Defocusing to near the pupil clearly shows the wind and turbulent patterns in space and time. Defocus means you are focusing someplace else, and as you focus from near the telescope up through the atmosphere, the visible structure changes dramatically. You can run past focus and see even different patterns, including the apparent wind directions reverse. You can also think of the light propagating inside the telescope from the pupil where there is only weak scintillation and random phase aberrations, to stronger and eventually very strong scintillation as you move back towards the focal plane. There is a lot of information available in the very defocused images that has been surprisingly under-studied. Defocus near the pupil plane has been used for linear curvature wavefront sensing using ray theory arguments. It is possible to use paraxial wave theory to do a better job out until where the Fresnel scale (sqrt(lambda z)) becomes comparable to the Fried length r0. Beyond that, nonlinear effects dominate the scintillation and you get caustics and refractive modulation, mixed with diffraction from both the scattering and the telescope optics. Scintillation statistics are more complicated than "seeing" statistics because they require at least fourth moments while seeing is described by second moments. There's more to be learned here and I am just exploring.

  • @Jestak
    @Jestak 8 лет назад

    Thank you for posting this. I may have been in the audience at this performance--my parents took us to the Festival of Light two or three years in a row in the 1970s. There are some bits and pieces that I definitely remember, like the soloist singing "Welcome, Yule" at the beginning.

  • @cutekawaiicharms5752
    @cutekawaiicharms5752 9 лет назад

    Wooo aberdonian and GODALM PROUS

  • @jlcodona
    @jlcodona 9 лет назад

    en.wikipedia.org/wiki/Au_clair_de_la_lune French: " Au clair de la lune, Mon ami Pierrot, Prête-moi ta plume Pour écrire un mot. Ma chandelle est morte, Je n'ai plus de feu. Ouvre-moi ta porte Pour l'amour de Dieu. " Au clair de la lune, Pierrot répondit : " Je n'ai pas de plume, Je suis dans mon lit. Va chez la voisine, Je crois qu'elle y est, Car dans sa cuisine On bat le briquet. " Au clair de la lune, L'aimable Lubin; Frappe chez la brune, Elle répond soudain : -Qui frappe de la sorte ? Il dit à son tour : -Ouvrez votre porte, Pour le Dieu d'Amour. Au clair de la lune, On n'y voit qu'un peu. On chercha la plume, On chercha du feu. En cherchant d'la sorte, Je n'sais c'qu'on trouva ; Mais je sais qu'la porte Sur eux se ferma. English: "By the light of the moon, My friend Pierrot, Lend me your quill To write a word. My candle is dead, I have no more fire. Open your door for me For the love of God." By the light of the moon, Pierrot replied: "I don't have any pens, I am in my bed Go to the neighbor's, I think she's there Because in her kitchen Someone is lighting the fire." By the light of the moon Likable Lubin Knocks on the brunette's door. She suddenly responds: - Who's knocking like that? He then replies: - Open your door for the God of Love! By the light of the moon One could barely see The pen was looked for, The light was looked for. With all that looking I don't know what was found, But I do know that the door Shut itself on them.

  • @jlcodona
    @jlcodona 9 лет назад

    Stopping by Woods on a Snowy Evening BY ROBERT FROST Whose woods these are I think I know. His house is in the village though; He will not see me stopping here To watch his woods fill up with snow. My little horse must think it queer To stop without a farmhouse near Between the woods and frozen lake The darkest evening of the year. He gives his harness bells a shake To ask if there is some mistake. The only other sound’s the sweep Of easy wind and downy flake. The woods are lovely, dark and deep, But I have promises to keep, And miles to go before I sleep, And miles to go before I sleep.

  • @jlcodona
    @jlcodona 9 лет назад

    Robert Frost (1874-1963). Mountain Interval. 1920. 1. The Road Not Taken TWO roads diverged in a yellow wood, And sorry I could not travel both And be one traveler, long I stood And looked down one as far as I could To where it bent in the undergrowth; 5 Then took the other, as just as fair, And having perhaps the better claim, Because it was grassy and wanted wear; Though as for that the passing there Had worn them really about the same, 10 And both that morning equally lay In leaves no step had trodden black. Oh, I kept the first for another day! Yet knowing how way leads on to way, I doubted if I should ever come back. 15 I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I- I took the one less traveled by, And that has made all the difference. 20

  • @jlcodona
    @jlcodona 9 лет назад

    The Pasture BY ROBERT FROST I'm going out to clean the pasture spring; I'll only stop to rake the leaves away (And wait to watch the water clear, I may): I shan't be gone long.-You come too. I'm going out to fetch the little calf That's standing by the mother. It's so young, It totters when she licks it with her tongue. I shan't be gone long.-You come too.

  • @xxwolfloverdoesgaming5566
    @xxwolfloverdoesgaming5566 9 лет назад

    Andrew Cross- I agree im also going ro Codonas today to meet workers i made friends with there and also go on rides of course my fav rides are the Waltzers and the Vertigo

  • @jlcodona
    @jlcodona 9 лет назад

    Hi Davi, The light was split between the cameras using beamsplitters. They are all at different distances along the optical path between a relayed pupil plane and the focal plane. Since the cameras are at different positions along the optical path, they don't block each other.

  • @stuartriddle919
    @stuartriddle919 9 лет назад

  • @jlcodona
    @jlcodona 9 лет назад

    Hi Kedi, sure! But how did you come to such a place in life? ;-) Write to me at jlcodona@gmail.com.

  • @nurdanbaci
    @nurdanbaci 9 лет назад

    Hi Johanan, I need to learn split step method. İs it possible that you can teach me? Thanks a lot.

  • @11ASCT
    @11ASCT 10 лет назад

    the scotlnd codonas have been scamming the public for over 200 years...!!!!

  • @jlcodona
    @jlcodona 10 лет назад

    +Sallie, Lalo Alfred Codona was the nephew of the Victoria Codona Adolph you knew. Her youngest brother, Edward, was the one who owned the cabins in Crestline. Lalo Alfred was named for his brothers.

  • @pearlbegonia5676
    @pearlbegonia5676 10 лет назад

    Well done! Funny and lively!

  • @sebauri88
    @sebauri88 10 лет назад

    Great demostration!! Im new in the field of adaptive optics, its very impresive how it works ... you used the drivers provided by thor labs or you made it all?? i bought a BMC MEMS DM and i need controled by matlab i need install something extra in matlab to run this type of script??? ... sorry im a newbie in this area Thanks :D!

    • @jlcodona
      @jlcodona 10 лет назад

      Hi. I wrote a Linux USB device driver that talks to the DM controller. You can find the code on github. github.com/jlcodona/BMCUSB

  • @SalBug2
    @SalBug2 10 лет назад

    Is this the Lalo that was Victoria Codona Adolph's brother? If so, I remember meeting him and some of his children up at Victoria's Crestline/Lake Gregory cabins.

  • @sachas420
    @sachas420 11 лет назад

    God Bless his family. I feel your loss and still miss him today and think about what he taught me daily. Never have I met a man so dedicated to our Lord.As I sat down today to go over next years calendar I ran across this beautiful memorial video of a Loving and righteous man that our Father so graciously put in my families life. I am still learning from what he taught me about Jesus. His life has been the most perfect example of how wonderfully close we are able to walk with God.

  • @antoniod
    @antoniod 11 лет назад

    There's a German movie about your great uncles, "Die Drei Codonas", made in 1940. Did you ever see it?

  • @TheTEAMBUTLER
    @TheTEAMBUTLER 11 лет назад

    Remember the laughing clown... Scary

  • @mezuah4
    @mezuah4 11 лет назад

    Sunny Aberdeen?

  • @kevinchindes
    @kevinchindes 11 лет назад

    place is still full of the rides from 40 years ago

  • @bob4jjjj
    @bob4jjjj 11 лет назад

    Ah, Aberdeen beach and Cadonas. Memories :-)

  • @titanplayer500
    @titanplayer500 12 лет назад

    Robby was a perfect Thenardier. He's working on a three men show with two other titanplayers. I'm not one of the three. That show is called "The Complete Works of William Shakespeare Abrigde".

  • @illbychoice
    @illbychoice 12 лет назад

    robby is amazing in this ILL BY CHOICE

  • @jlcodona
    @jlcodona 12 лет назад

    We aren't sure, but it appears that our family trees converge in the early 1800s. We were the Flying Codonas or Los Codona circus family and Lalo's great grandfather was from Scotland.

  • @CHEYYYYYYYYYYY
    @CHEYYYYYYYYYYY 12 лет назад

    may i ask how lalo is related to the codonas in aberdeen?

  • @61Omega
    @61Omega 13 лет назад

    Very interesting indeed........

  • @whatsupAndrew
    @whatsupAndrew 13 лет назад

    needs to be made bigger, and loads more rides added !!!!

  • @SuperGirls144
    @SuperGirls144 13 лет назад

    I mean just WONDERFUL!!!!!!!!!!!!

  • @SuperGirls144
    @SuperGirls144 13 лет назад

    Great