ASKAP Timelapse, WA

[alexch]

Hi All,

I've been to the outback WA this New Moon filming the dishes of the Australian SKA Pathfinder telescope. It took a while to process 19960 images done with 3 cameras during 5 nights. Finally the timelapse is online (put the sound on):
http://vimeo.com/terrastro/askap

It was an unforgettable experience - I stayed at the telescope during the day, helped scripting and testing the antenna movement for the night with CSIRO scientist Max Voronkov and just enjoyed the remote location with no mobile phones.

It is a very impressive instrument with 36 antennas (with only a handful connected yet) spread over 6 km making it somewhat difficult for photography but I tried hard to find good angles. The telescope is in testing phase and it may not be possible to film there in the future due to Radio Frequency Interference once the testing is complete. The central building looks very cool with the RFI shielded doors and no windows.

CSIRO might use the timelapse for publicity in association with the opening day scheduled for the end of next week.

Cameras: Nikon D700 and D3s, Sony NEX5N.
Lenses: Nikkor 70-200mm f/2.8, Nikkor 14-24mm at f/2.8, Samyang 35mm f/1.4 at f/2, Sigma 8mm f/3.5 circular fisheye.
Some moves with Dynamic Perception Stage Zero, pans with Vixen Polarie.

Don't ask me how did I get all that stuff on the plane...

Some stills attached.

Cheers,
Alex

[bartman]

WOW!!!!
Absolutely Gobsmacked Alex!
Tremendous effort. I particularly like the cherry picker working on the dish at night and the Fish Eye sequence. ( and all the rest to be honest!)
I certainly hope that the timelapse will be used for the opening! You deserve it!
Thanks very much for sharing!
Bartman

[Octane]

I saw this on Facebook the other day. Remarkable effort, Alex. Kudos to you.

H

[iceman]

Stunning work, Alex. Loved the cherry picker scenes too.

Well done as usual!

[stardust steve]

Very entertaining. The highlight for me was around the 2 minute mark where the Milky Way was setting parallel to the Earth. Magic:thumbsup:

[CapturingTheNight]

Stunning work as always Alex :thumbsup:

[geoffsims]

W O W !

That is seriously amazing work, well done. It is a pretty interesting effect when the all sky fisheye is rotating.

[astroron]

Brilliant as usual Alex:eyepop:
Really shows the beauty of the Night Sky and how busy it is with meteors and satellites.
Cheers:thumbsup:

[rogerg]

Excellent work Alex.

You've obviously put a lot of planning and time in to organising the trip and then being there and yet again processing.

I would find it hard in that situation choosing angles to photograph from. there would be a lot of choice. I suppose where the Milky Way will besetting would narrow that choice significantly, so possibly not as hard as I first thought, but still, to maximise the time out there I would feel the pressure of picking the right places to photograph from :)

[gregbradley]

Wow, that is terrific work Alex.

What camera/lens combo was the last scene done with?

It seems exceptionally sharp and detailed with pinpoint stars. 35mm F1.4 and shortish exposures?

Greg.

[RickS]

Lovely work, Alex! I enjoyed it immensely.

[andyc]

Once again, wow - very impressive. On the all-sky view at 1:48-1:52ish, in the upper/upper right part, I think you have a train of geostationary satellites winking in and out in southern Aries/Taurus along the line of ~10deg N. Been looking to see them in timelapses - very cool! And the all-sky view shows the Ecliptic dust too. So many interesting things in your timelapses, and always visually sumptuous.

[colinmlegg]

Superb effort Alex. You nailed it mate!

A couple of questions:

1. What's the power source to the site? I guess all the cables are shielded.
2. Can any of the scopes be moved...on rails?

[alexch]

Thanks Colin!


Currently some antennas are on the grid power from a diesel powerplant and some we were connecting to mobile generators. It will all be on the grid power very soon. All cabling is underground and I presume is well shielded.


No. They are fixed on the ground but can move in three axes - alt, az and rotational. The rotation is the first in the world. Other antenna designs rotate the receiver but rotating the whole dish eliminates diffraction from the support struts.

[alexch]

Thanks!

Yes it was the 35mm Samyang at f/2 and 15-second exposures with D3s.

[alexch]

Gents - thanks a lot for the compliments and nice comments!

[mswhin63]

Beautiful shots Alex, I stayed at Wooleen station while working on the MRO and the skies are just beautiful out there. I never got the chance to stay over night at The MRO though.
Wooleen also had the South West Astronomical Society out there although I believe the dust was playing havoc.

[multiweb]

Very cool footage Alex. Well done. :thumbsup:

[Phil Hart]

nice work as always alex. no doubt you had fun out there in the dark. i like the fisheye shot too :).

having no light pollution domes in any of the shots is impressive and there's a great zodiacal band through the fisheye shot. what was your impression of the darkness of the skies visually.. any difference high in the sky to other victorian dark sky sites?

i do want to know how you got it all on the plane though! :P

cheers
Phil

[alexch]

Marc and Malcolm - Thanks heaps!

[alexch]

Thanks Phil.
Indeed these were the darkest sky I have ever experienced. The first night there was no airglow and the sky background was subjectively a little darker than I have seen elsewhere. I wish I had my SQM with me but even 200 grams of extra luggage weight were potentially a problem.

On subsequent nights there was airglow and I wouldn't say there was a huge deal of difference to the Victorian dark sites. Seeing the Milky Way set parallel to the horizon and then disappear was very cool though.

We'll have to talk about the luggage over beer:). Are you going to VicSouth this year?

[colinmlegg]

It's pretty rare to get a night completely free of airglow out there. I've only experienced a couple. One at karijini and the other wolf creek crater. Most of the time some yellow, red or green airglow is visible in the shots.

[Peter Ward]

A masterful effort. I enjoyed the sequences immensely. :thumbsup: :thumbsup: :thumbsup:

[Phil Hart]

hmmm.. i would like to go to vic south but can't make it now. will be using the saturday to practice eclipse imaging.. only weekend day i have at home in october! beer will have to wait for another time.. :thumbsup:

[Ric]

Awesome work Alex

Cheers

[iceman]

You are a master, Alex.

This is now IOTW (http://www.iceinspace.com.au).

[bartman]

This could even be VOTW / VOTY........
As much as I like the pic used for IOTW , it must have been hard to choose one Mike. I seriously love the cherry picker one and also the last one ( shows the distance between scopes and remoteness ).
Great call none the less!
Congrats Alex!!!!!
Bartman

[geoffsims]

Alex, Phil, Colin:

A quick note regarding airglow. You need to be careful when comparing the darkness of sites, even if using a handheld meter. Airglow fluctuations are quite complex. As seen in most time lapses, it is obvious to us airglow varies on short timescales (~minutes). There are also larger diurnal, and seasonal effects that come into play. Lastly, it fluctuates on decadal scales with the solar cycle. If you have access, there are many great papers in the literature about this.

See e.g. http://arxiv.org/abs/astro-ph/9706111

Average Mauna Kea sky brightness varies by 0.5 mag/arcsec^2 over a solar cycle!

Also see: http://arxiv.org/abs/0801.2270

My point is it is very difficult to visit a site once, and draw conclusions on its sky brightness (more specifically the amount of airglow present or not) relative to other sites. Light pollution aside, of course there are other factors that come into play (e.g. the latitude of the site will determine the range of angles that the zodiacal light will be be seen at, which will vary throughout the year...), but airglow is the dominant source of sky brightness in the optical bands, so is of most relevance here.

[colinmlegg]

Geoff, thanks for those links. I agree and I guess that's my point as well. In my experience it's rare to see no airglow and it does seem to have a large influence on sky brightness. Even up on the altiplano in Chile where you'd expect the darkest skies, there's often quite strong and variable airglow...at least the 3 times I've visited.

[alexch]

Indeed, in light-pollution free skies, airglow and zodiacal light pose a significant background sky noise problem for professional astronomers.


The fisheye sequence was from the first night and it was free from significant skyglow in the beginning. It was then when I thought "wow, this looks darker than anything I have seen before". It was probably due to low humidity and good transparency too.

However you are absolutely right - it is impossible to compare apples to apples here. For example on those two memorable nights in the observatory on La Palma there was a significant airglow and the sky looked a little milky. In New Zealand it was so strong (following a big geomagnetic storm) that I think I saw the airglow patterns naked eye. I'll try to make a habit of taking circular fisheye images throughout the night at dark sky locations in the future and build up a database. (Do I need another camera?)

Cheers,
Alex

[pvelez]

Have carpet burn on my chin

The best images I've seen in many a year

Thanks for that.

Pete

[FlashDrive]

Alex .... As usual ...nothing but the ' Best' ... Keep them coming ..!!
Love watching your Timelapse's. :thumbsup:

Flash ..!!

[alexch]

Col, Pete - thanks!
Mike, thanks for the IOTW!
Alex

[colinmlegg]

I think you do Alex ;). So how many tripods did you take to WA? For plane flights I pack my DP S0 beam + 2 tripods (minus heads) and all clothes in a flexible 7 foot ski bag. Electronics (Laptop,MX2,bramper,etc.), cameras and lenses go in a carry on back pack or hand held bag. Anything else not breakable like tripod heads go in a 2nd suitcase. Worked nicely on the Chile trip, although I do feel like a slave to the technology at times. ;)

[Phil Hart]

We're on exactly the same page Geoff!

http://philhart.com/content/airglow-and-other-thoughts-dark-sky-sites

Just cause you have a small light pollution dome on one horizon doesn't mean the zenith sky brightness is objectively worse than the darkest of dark sky sites. Airglow is a very significant limiting factor. Alex's visual observations about what he could see matching the fisheye images is interesting though!

Phil

[jjjnettie]

Brilliant work Alex. :)

[alexch]

4 tripods + 5 heads, chargers, DP cart in a luggage bag. Then DP beam in a flexible Aldi ski bag and another suitcase for more gear and some personal items...
It was challenging but doable.

[ourkind]

+100

[strongmanmike]

Now, I guess that's quite a reasonable backdrop for night scape work....buuut hey my dead tree isn't too far behind :whistle:....:lol:.....:help:

Great stuff Alex, some of you guys get to some awesome locations, I must say :eyepop:

If I may make one slightly negative comment and far be it for me to critique a master :question:... but many of the sequences were rather randomly jerky on my moniter, I have a good fast internet connection here at work too, is it me or the sequences...?

Mike

[alexch]

Thanks! Indeed that tree shows a lot of potential :)

I don't think it is you, Mike. But it is likely to be your computer, graphics card or Adobe Flash that make the timelapse stutter.

Try in a different web browser.

Cheers,
Alex

[mbaddah]

Alex I have probably watched every milky way time lapse video out there on the web and I would rate this as among one of the best I have ever seen.

I loved it so much I've put it on my phone to repeatedly watch :) Well done.:thumbsup:

[lacad01]

Very impressive Alex, great sequence and music really fits in. Lucky to be able to get that close before the electronic noise embargo. :thumbsup::thumbsup:

[geoffsims]

Phil,

That's very interesting data, very nicely collected and analysed.

How sure are you the dips are caused by the zodiacal light & milky way? I'm not really convinced, nor am I convinced scattered light from Venus would affect the sky brightness at the SCP noticeably (but I could be wrong). If the data is taken in November, it could even be scattered sunlight since it gets dark quite late - true darkness sometimes does not occur until the Sun is 20 degrees below the horizon - the time at which it becomes dark being most dependent on aerosols in the atmosphere - more aerosols, more scattering, gets dark later. Could also be compounded with some diurnal airglow variation.

If you had the time, you could do photometry on a few stars in that region to obtain a calibration, and convert those pixel intensity values to mag/arcsec^2, which would quantify how large the variations really are. It would also be useful it you stated the field of view of that 100 px squared region (I can't be bothered to work it out...!)

Anyway - enough random thoughts and ramblings...

[Martin Pugh]

Outstanding work Alex

My wife works for the dept of Innovation and Science who have been working/are associated with ASKA. They are all aware of your work and have actually confirmed that it will get played on opening night tomorrow.

well done
Martin

[zardos123]

Well done alex, i noticed that it is being featured and then used as a background for the ABC national news and news 24 :thumbsup:

[strongmanmike]

Finally have our high speed internet connected at the new property and with my home computer (as opposed to my work PC) it looks spot on now :thumbsup: Funnily enough our connection out here is much faster than it was in suburban Newcastle, which is great.

Nice work mate

Mike

[Jo41]

:thanx:Wow! what a treat! beautiful work. I LOVE IT!!!!

[AstroJason]

I think I have watched this about 1000 times now! Really love your work here Alex. Very inspiring stuff. You must've really enjoyed your time out there shooting this.

[Adelastro1]

Wow fantastic Alex! I just saw it on our Adelaidenow newspaper website. I'm very envious that you got up there for imaging too! Well done.

[Paul Haese]

Inspirational work. Your video sequences get better and better all the time. Between you, Phil and Colin I watch in awe. Lots of work involved and dedication to the plans. Congratulations.

[Larryp]

Absolutely wonderful! And the music is brilliant for the purpose.

[malclocke]

The video was on TV3 news here in NZ last night, certainly doing the rounds! Great work.

Malc