Hi,
I'm probably repeating some of whats been said already but hopefully this will provide more food for thought.
Light pollution would be a very significant factor. City center light pollution will restrict you to only really being able to view the moon and the planets. Even at that the air turbulence from the city would not enable you to get good seeing, this can be mitigated somewhat by image processing techniques, but will be a problem for letting people look through the telescope.
To keep the facility assessable you would need to choose a site that was probably on the dart or luas lines, and with decent road access.
From an astronomical point of view you would want to have the observatory set up on the south side of the city. I'm not being biased against northsiders here! Hear me out! Constellations like Sagittarius, possibly one of the most interesting in the sky are only visible in the south. The planets are only visible towards the south (by that I mean they are never in the north!). So you would want the telescope to have the best possible view southward without any light pollution. Assuming you could build anywhere this would favour Dalkey/Killiney hill or Bray head as the best site, you have complete darkness to the south(ish) and low horizons. If that is not practical perhaps there is some higher ground near the end of the luas line around kilmacud or sandyford.
If you are building an observatory an optical telescope is a must. For Public Outreach, regardless of all the nice VLT and Hubble images the public still expect to be able to see through a telescope. Researchers will not be as interested in this since the majority of their work is done on much larger telescopes, but the universities in Dublin would probably have an interest in this as a training ground for their undergrads.
A ccd/webcam or some image gathering capability would probably also be required. It would need to be easily attached to the telescope so that kids for example could look through the scope and then in a classroom setting have the image displayed on the projection screen/TV. I would imagine some webcam/video type setup would be ideal for planetary work, but also a more specialised CCD would be nice for advanced amateurs or students to use. Though when we think of students and amateurs its probably work thinking of what is needed to do photometry, spectroscopy etc.
An outdoor area would be a very good idea. This would allow the center to be used more by amateurs to organise their own public nights or to assist with the observatories public nights. This could be on a flat stable roof I suppose if the building has a lift!
Some h-alpha scope or adaptor to the main scope would be another useful addition.
Radio astronomy probably has limited usefulness. With the radio interference from Dublin very little could be done, perhaps just tracking the sun, the milky way or a couple of the other main sources. On the plus side It could give visitors an opportunity to “hear†the sun or galaxy. A big dish would look well also.
There are only types of astronomy events that you can use. Those provided, eclipses, meteor showers, transits; and those you provide Lectures, workshops etc. Thankfully most of these are predictable.
You also need to build up a relationship with the public. Its no use to have some elaborate one off event and then nothing until the next one. Things like the Venus transit were excellent for public outreach, but there is no comparable event coming up for the next while. By comparable I mean with the same historical significance, rarity, challenge etc.
Having a lecture hall and exhibition is a very crucial component in my opinion. Most of us see astronomy as something to do at night, but to get engagement from schools you need to be able to have them come in during schooltime and experience astronomy. That's when the h-alpha scope comes in, also a regular white light filter on the main scope for comparison.
Another thing worth looking into is linking up with other observatories. If its cloudy you need backup plans and to be able to operate or at least get image feeds from other telescopes around the world would be of benefit. Bart can elaborate more on this on a professional level with schools, and the example of the Norwegian Amateurs of having amateur observatories set up with webcams for events may also be worth looking at.
To have the lecture areas be worthwhile they will need use, so you would need to provide evening classes, workshops etc. The exhibitions would probably need to be a bit more than a room full of old broken telescopes too, an approach more like that of
www.w5online.co.uk/
in Belfast, or the Glasgow science center would be better. In fact the glasgow science center with an added observatory would be a good project to compare your ideas against, they have put a lot of thought into architectural design
www.glasgowsciencecentre.org/
Bart also mentioned a shop. I think everone here would love to see a competitive shop where we can walk in and see telescopes in Dublin. It would need to be staffed by people who know what they are talking about and of course would need to be competitively priced. As well as scopes of course there are books, gizmos, and souvenier stuff that could be incorporated.
In addition a coffee room could be added. Depending on the location this could serve to attract people in. In areas where there are going to be people.
You might also like to contact Mike Redfern in NUIG whose observatory is situated within the city limits for more on light pollution, though Galway is not as bad as Dublin. Also Robert Hill in Armagh for how they handle the observatory and planetarium and manage it, Armagh city council have light pollution guidelines to reduce pollution in the city primarily to help the observatory, if such a complex was to be developed in Dublin I would think it would be certainly acceptable to push the local council to introduce anti light pollution ordinances and have their response as part of the decision of where to build the site.
Cheers,
~Al
