Thank you for the update - it is encouraging for me that planning for future activities is continuing, even as the 'self isolation' of households limits what can be done.
I am particularly interested in hearing about the search for an observing site - would it it be possible to make a short report to members on this (criteria, examples, constraints, etc) and would like to contribute if I can.
On Sat, Mar 28, 2020 at 7:30 AM NSAS <email@example.com> wrote: (David Stevenson post)
Thanks for showing interest in our site search. We earlier formed a sub-committee in an attempt to give our search some focus and put some focus on the task. We have been reporting to our general meeting as well as the committee as we go along but given our meetings have come to a halt, it's perhaps a good time to provide another update. I’ll also include some background information you might have missed earlier.
First up, our subcommittee's site selection criteria. We developed the criteria to keep in mind as we consider the merits of each site which I’ve included below.
After some discussion on many site options, the sub-committee decided to put a stake in the ground and investigate 15 options. Some of those included near the northern side of Sydney and 3 were a few hours north. Most sites have been investigated by at least one person from the sub-committee but most have been visited by a few. We have also tried to investigate ownership and national parks or council zoning of any sites.
Our existing site is included as we would like to shore up the arrangement with the council to provide a bit more certainty of our tenure rather than the roughly 12 months in advance we have with council sometimes booking the site on our night for others.
To date, of the 15 sites, we have eliminated 6 sites from the list. We have grouped our preferred sites into two categories. Those sites that would match the cost structure of our existing Terrey Hills site so we can continue to run without the pressures of money, and a developed site that might use up significant society reserves, as well as require the society to add a fundraising component to our yearly tasks. We also have a group of sites that we have put on the back burner for now as they would require a lot of red tape and money and divert focus from the most promising sites. These back burner sites could also require some significant money and we might also have to rely on any government grants and goodwill for access.
If you have any sites in mind that would meet our criteria, please let us know.
A new site must be within easy driving range, north of the Harbour, and south of the Hawkesbury River.
The car parking location must have a clear exit area for cars to exit without lights.
Be able to restrict access to NSAS approved people.
Capable of giving access to at least 3 “key” holders.
The new site must have easy access for vehicles to park and unload Telescopes.
The new site must have a clear Horizon, with no obstacles above 20°.
Preference to no flight path above 40deg to the horizon.
Preference to a sealed area, such as a narrow asphalt road, to setup astronomical equipment.
The new site must have an SQM of greater that the current site at Terrey Hills.
The new site must be away from roads with street lights.
The new site must be away from streets with passing cars.
The new site must be at a low cost to NSAS.
Any new site must provide medium to long term tenure opportunities (minimum of 5 years) and the ability for NSAS to exercise a degree of control over its ongoing use and development for astronomical purposes.
Hello and thank you for sending the progress report. A long-term facility which could be used and gradually improved would be a great asset.
Regarding the criteria, I assume the SQM measured at the Terrey Hills site is about 20.4 and elevation is about 200m. Over the past several decades, I have used darkish sky sites in the Blue Mountains and on the NSW south coast (south of Kiama) where there are some sites with estimated SQM readings above 21.5 within two hours drive from Ryde. One thing I have noticed over the past decade is how quickly many previously darkish sites have been affected by new residential developments, roads, and new streetlights. Perhaps the site criteria could include an assessment of the likelihood of future development nearby (based on current land use zonings)?
I have not done any observing at sites north of Sydney so cannot offer any suggestions for these. However, if you want to further investigate any potential site you have identified I could perhaps help with this.
Interest: Astrophotography, Dark Matter Black Holes etc Equipment: Celestron 8" Edge HD
Skywatcher Esprit 120mm APO Triplet Refractor
Skywatcher AZ EQ6 Pro mount
ZWO 1600mm pro cooled camera
EFW 5 Band filter wheel
ZWO ASI290MM mini guide camera
hi Rob. We agree and one of the criteria that I think Greg mentions is that we are looking for a 5-10 years horizon. They is no doubt that Terry Hills will be affected in time and this is part of our deliberations.
Celestron 8" Edge HD Skywatcher Esprit 120mm APO Triplet Refractor Skywatcher AZ EQ6 Pro mount ZWO 1600mm pro cooled camera EFW 5 Band filter wheel OAG through ZWO ASI290MM mini guide camera