Dawn of the Robots, or 'How Robotic Imaging Saved My Sanity'
- Created: Friday, 12 September 2014 12:44
- Written by Ralph
Like all astronomers I love my astro gear, but I hate light pollution, horizon obscuring buildings and trees and, of course, clouds. Up to very recently the amateur astronomer has either been stuck with the cards they have been dealt in terms of location, or has had to pack everything into the car and head off to darker skies and broader horizons. With the foundation of observatories that enable amateurs to book time and operate scopes remotely, in the way professional astronomers have for years, this is no longer the case.
My view of robotic imaging was always that it’s a bit of a cheat really, taking pretty pictures from the comfort of your home? You’ve got to earn those images through investing in the best gear you can afford and lugging this heavy equipment outside (preferably when its freezing cold), setting it up, polar aligning, checking alignment, polar aligning again, focussing, starting your imaging run….then watching the clouds rolling in whereby you have to stop and take everything down and pack up for the night, only to begin again the next time you believe a weather forecast!
Living in London I’ve come to realise that my location precludes me achieving the results I’m after when imaging deep sky objects. Not only am I in an extremely light polluted location but the nature of a city garden means that a clear horizon is pretty much an impossibility, throw in the British weather and I thought why not give remote imaging a go? My intention was to see whether this approach would help when imaging challenging DSOs or those objects not visible or poorly placed from my latitude/location. I’m not intending to give up on the ‘hands-on’ approach, rather I’d like to explore using remote telescopes to broaden my imaging horizons, enabling me to use top spec equipment at a dark sky location and hone my processing skills on quality, calibrated light frames rather than the more disappointing results I was achieving at home (and I know a lot of the blame lies with me and lack of skill, not just my environment!).
A simple google search reveals that there are a lot of providers of robotic telescope services but I decided to try out two of them, The Bradford Robotic Telescope Programme and the grander iTelescope. The Bradford Robotic Telescope is part of the Observatorio del Teide on Tenerife sited at an altitude of 2,400 metres, iTelescope has four sites at Mayhill New Mexico, the Sierra Nevada Mountains in California, Nerpio in Spain and Siding Spring Observatory in Australia. Here iTelescope has an obvious advantage as you can image 24hrs a days should you wish to, weather and bank balance permitting.
In terms of the equipment at these locations the Bradford Robotic set-up is a simple one consisting of one Paramount ME mount upon which sits a Celestron C14 f/5.3 OTA (focal reducer employed) named ‘Galaxy’ with FLI Microline camera and 8 position filter wheel. Attached to the C14 is ‘Constellation’ – Nikon 16mm f/2.8 lens and FLI Maxcam CM2-1 and ‘Cluster’ – Nikon 180mm f/2.8 lens with the same camera set up as that on ‘Galaxy’. iTelescope has a much more comprehensive and impressive line up of 18 scopes with apertures ranging from 106mm f/5.0 to a massive 700mm f/6.6, most enable you to use a full range of filters. As a way of illustrating the quality of the equipment the ‘try for free’ set-up includes a £10,000 scope with £2,000 CCD attached! I won’t go into the full specs here but you can find all the details in the ‘The Telescopes’ section of the iTelescope website.
So that’s the gear but what is the experience of using it? The Bradford Robotic subscription process is simple and straightforward with £3.00 per month allowing you to take 10 images with any of the set-ups described above. The user interface is clean and easy to use, simply click use telescope and it will guide you through selecting your object, telescope and filter/exposure as well as the application of configuration files. The site recommends you stay at exposures of 2 minutes or less but I did manage a 3 minute exposure with no trailing. Once you’ve entered all the details you submit your request and wait, there is no option to reserve the scope so you have to wait your turn, the scheduling software deciding on the best time to image your selected object. One important point to note is that the scheduler won’t stop you choosing an object that is too low or close to the sun to capture – you’ll just never receive the image and it will remain on your queue, you can however delete it and free up one of your valuable image slots again. Eventually depending on the weather and how busy the scope is, and it can take a long time, you will receive an email telling you your image is available. You then log on to the website and download your image, then you can further process in the editing software of your choice. There is some basic editing available on the site if you haven’t got access to Photoshop, GIMP etc. The image produced remains the property of University of Bradford, so you won’t have copyright on your images though you can freely distribute them.
The quality of the images produced using the Bradford Robotic is pretty good within the constraints of the exposure times available, but you are never going to make APOD with them, however at the low cost of subscription I’d say Bradford Robotic offered excellent value for money and is great for a novice astrophotographer who wants to take the first steps in CCD imaging and processing or the more experienced user who merely wishes to dabble in remote imaging.
Now to iTelescope, this is a different beast altogether, it really is like controlling your own scope – you reserve it and use it during that time as if it were your own and the images are all yours. A key difference with Bradford is that you are not charged per image but rather on a points per telescope per hour basis. You receive points according to your subscription level and these are deducted as you use the scope you have chosen on any particular night (points are only deducted when the CCD is active), the big beasts being much more expensive points wise than the smaller scopes. There are also discounts applied according to moon phase and whether it is in the sky or not. Of course it makes sense to try out the service before making any financial commitment and iTelescope has an excellent demo account facility for which you receive 40 points and access to some of the smaller scopes in New Mexico and Siding Spring. I’d recommend going for the demo upgrade which for around £3.00 gives you an extra 30 points, access to more scopes and the ability to schedule runs etc., providing you with a much better feel for the service and enabling you to make a much more informed decision as to whether to take the plunge fully or not.
Now you’ve subscribed you are in a position to start the Launchpad – this is where it all happens, and once you’ve grasped a few basic concepts it is pretty easy to use. There are three drop downs ‘Select Action’, ‘Reservations’ and ‘Offline Plan Generator’. ‘Select Action’ lets you manage your account and access your images (via web or FTP), ‘Reservations’ is where you log on to the individual telescopes and ‘Offline Plan Generator’ is where you can create imaging runs on individual scopes. The individual scopes thing is important, each is independent of the others, you log on to the scope and perform actions there, you can make reservations, generate an observing plan or load an observing plan which can start automatically at a specified time while you sleep (handy for the scopes in the US west coast). If the scope is available and active you can also use it to image there and then using a handy ‘one click’ imaging facility. I did this to image NGC104 (47 Tucanae) using telescope 13 at Siding Spring. Sitting at my kitchen table in London I was able to watch the script running showing me the scope slewing, focussing, plate solving, guiding and finally acquiring the image using a 10 minute exposure. Once it had finished I could view a preview of the acquired image, then hop on to the download images part of the Launchpad and bring the images down on to my laptop for processing. Easy as that, I’ve also used scopes T18 in Nerpio to image NGC7635 (the BubbleNebula) and T5 in New Mexico to image M27 (Dumbbell Nebula) in Ha, R,G,B and Oiii, R, G, B respectively imaging via an observing plan. Anything you might wish to do is supported by the iTelescope setup and once downloaded you are working on images you’ve captured yourself, basically you are only limited by the level of your processing skills – APOD here we come!
So my conclusions, well nothing beats the sense of achievement of capturing and processing a fantastic image with your own gear, ‘soup to nuts’, but quite often the quality of the image depends a great deal on how deep your pockets are, and that’s kind of unfair. Location is also something we are generally stuck with, if you happen to live in the dead centre of Australia or the Arizona desert you are at a bit of an advantage when it comes to the quality of the images you can produce. Having said that I know this approach to imaging isn’t for everyone, if you love gear and want to be totally hands-on then I wouldn’t recommend it. You also have to be patient, it’s a shared resource so you have to book or wait your turn so you can’t just decide to do a little imaging when the mood takes you. If however you want to broaden your horizons in terms of available objects or try things your location precludes then creating an imaging plan and running it is no different on a robotic scope than if you were running it on your own CCD attached to a scope in your back garden. The difference is you are taking advantage of gear that is (probably) way better than you could hope to own yourself, imaging under skies of a quality you could only dream of. Image acquisition and processing is exactly the same regardless of the method you employ so we are definitely not removing the skill/creative element there!
If you are a solar system imager then this isn’t for you as neither of the services I used had planetary camera options, maybe one for the future. In my experience using robotic scopes has freed up more of my time to look through the eyepiece and fully appreciate what is out there rather than spend hours on a rare clear night trying to get my equipment to play ball. I’ll still take deep sky images with my own gear but maybe will be a bit more realistic over the limitations of my equipment and location, while still striving to improve my skills. I haven’t given up on my dream of one day having my own observatory at the end of my garden, perhaps then I’ll be remotely operating a scope that’s 20metres away rather than 16,000 km, there’s really no difference.