Bortle Scale Survey for Stellarium Based Project

Hi,

pdempsey wrote: I've edited the time and date fields as suggested, and added optional weather and seeing fields. I was going to take a statistical approach, but that'll depend on the amount of data. I'm hoping the fact it's a structured naked eye test will improve responses. The Bortel scale is built into Stellarium, which is the reason for that choice. My focus is on the areas around historical observatories in Ireland, but I'll shared data with any interested parties, minus names and email addresses, but moderate noise will be added to GPS coordinates to protect anyone who may have reported from their homes (like me!!).

Good luck with it, I haven't seen a survey using those examples of the Bortle scale before. Hopefully that will improve the response among the amateur astronomers, the more traditional 'count the stars' approach works well getting the public and schools involved, but not so well with amateur astronomers!

Rough GPS locations is fine. Fine grained gives little benefit unless you really are looking for sources of light pollution.

TCD have been working on a datalogging meter that can be left in-situ on a site and will record the sky brightness (like the SQM datalogger), which potentially is something that could be installed at the historical observatories if there was funding. That could potentially then be used to calibrate the readings from observers at a distance from the site, to account for moisture in the air etc.

I'll post the link to your survey on our website.

Best Wishes,
~Al

Paul,

I submitted a report to the light pollution survey but I forgot to move the location cursur to my location.
So I have resubmitted again with the correct location and the same report. I think it was off by 100kms.
I also made a mistake in the Bortle scale readings. It should have read 1 and not 2.
The reason for the mistake is that most of the readings are Bortle 2 or 3 on my list. A March 22/23 , 2008 reading was a very rare exception of Bortle scale 1

Using the Cinzano Sky Brightness Map, my location is in the grey area which has a rating of 2 on the Bortle scale. ie.limiting magnitude of 7.1-7.5. I have been taking historical records of light pollution since 2003. For example, an exceptional record on sky brightness was achieved on March 22/23, 2008 when a reading of 21.74, taken at my location using a Sky Quality Meter (SQM) from Unihedron at in v. This exceptional reading was simultaneously monitored with to a 1.5 arc second reading of transparency taken by the STV camera/lens.. The SQM that is used is the original version that is manually operated. Routine measurements have taken every clear night with readings on average of 21.55 +/-0.5 since 2003. These measurements are taken at ~20 degrees from zenith with a Moonless sky.

The apparent sky brightness is between 2% and 15% brighter than the natural background. I have taken light bubble images generated by a series of photographs taken with a wide-angle lens on December 12/13, 2007. The images are stitched together to form a panoramic view. In 2007, I was concerned that the ever increasing developments and subsequent electrification from distant towns may effect the present dark location. However, with the halting of commercial developments in late 2007, the future looks good for the lack of light pollution for the next few years in the present location. There has been no increase in light pollution since 2007. Hooray! Economic crisis has some its benefits to astronomy

I hope this additional info may be useful in your research.

Eamonn

Thanks Eamonn,

I deleted your original submission. I might be in contact over the autumn/winter to try to convince you to take some readings in, and on the outskirts of, some nearby towns and villages

Cheers,
Paul

Paul,

Do you want naked eye readings manually based on the Bortle scale for your new survey? Or do you want Sky Quality Meter (SQM Unihedron))readings? Or both?

Eamonn

Either or. I'll be able to filter. If you have a existing data you can just mail it to me (paul.dempsey --at-- dazult.com). It's part of a project aimed more at the general public than serious astronomers, again using astronomy as a gateway to other sciences, so coverage is more important than accuracy; hence the naked eye instructions are provided on the survey page. To get the coverage I'm hoping to convince the college astronomy societies to do some naked eye readings when they start back in October, but sure we'll see how that goes.

Paul,

I have about 5400 readings recorded over the years in both Bortle Scale and "seeing" in arc seconds.
These readings were taken simultaneously. The seeing data is very accurate to +/-0.1 arc sec.
There are at least 100+ files of data. It may be easier just to send you the Bortle scale data only.

Eamonn