[SQM] minutes from SQM meeting

Christopher Kyba christopher.kyba at wew.fu-berlin.de
Thu Jul 7 12:36:57 UTC 2011

I wanted to forward this message to the list in case there are any
other SQM users out there who missed our first call to participate.
Briefly, an international group of light pollution researchers wants
to write a paper using data from fixed SQM stations.  If you'd like to
participate please send me an email.

Christopher Kyba
Free University of Berlin

---------- Forwarded message ----------
From: International Sky Brightness Survey <sqm at wew.fu-berlin.de>

Hello SQM users,

Today I had a phone discussion with Dorien Lolkema of RIVM of the
Netherlands and Andrea Giacomelli of BMP in Italy.  At the moment
those two groups are operating the largest networks of fixed-position
SQMs that I am aware of.  I wanted to share the results of the
discussion with you.

o I would appreciate it if everyone who wants to be involved would
send me a sample SQM data file for a single day (with your standard
filename, and including any headers) so that I can get an idea of how
varied the data formats are.  Please also send me your longitude and
latitude so that I can investigate what weather stations are nearest
you (you can send me that information, too, if you know it).

o The BMP group already has a fully operational open access online
database system, but it is in Italian and they don't have the
resources to translate everything on a short time scale.  It is
possible that in the longer term this system could be expanded to
other languages.

o If a database is established in the future, it will probably be
necessary for all of the users to adopt a common data format.  In
order to do our preliminary analysis I will convert each user's data
into a common format, so if you share your data I should be able to
provide you with a script capable of converting all of your old files
into the new common format (and possibly vice-versa).

o The goal of the first paper (which we will pursue independent of the
database) will be to get cloud-free measurements at each site, as well
as the overcast/clear brightness ratio.  It is likely that we will
have to remove the summer solstice period from some dark sites (and
possibly all sites).  We anticipate that this should still leave
enough data for a reasonable analysis.

o We think it makes sense that the dataset for the first paper be
fully available to the public at the time the paper is published.
There will be no obligation to share any data outside of the analysis

o If enough people participate we should gain significant experience
this summer in the potential difficulties of combining data from
multiple sites.  We hope to use this experience to write a working
paper suggesting best practices when taking SQM data and
recommendations for data format that we could distribute at the
Osnabrück meeting.

o The BMP group will probably bring their SQM calibration device to
the Osnabrück meeting, so if you are coming you could bring your SQM
(& housing!) to get it calibrated against many others.

o We will investigate the possibility of organizing a half day "SQM
Workshop" before or after the Osnabrück meeting, to discuss SQM
calibration issues, the working paper, the journal paper, and future
database plans.

o We didn't have a chance to discuss it on the phone, but I wanted to
bring up the issue of authorship for the journal paper.  My suggestion
would be that anyone who provides data is eligible to be an author,
and that since this is a large, collaborative group, we simply order
the authors alphabetically.

o We also didn't get a chance to discuss the IYA Lightmeter on the
call.  As many of you may know, there is already an open lightmeter
database.  I would suggest that we endeavor to include the results
from all available lightmeters in the same period.  While that data is
freely provided, I think it would make sense to extend authorship to
the people who are operating the lightmeters and the responsible
database persons at GAVO.

Finally, because it is the summer break for some people (and because
we don't all know each other yet), I would suggest that you reply to
me rather than to all, and I will collimate the responses and send
them all back to you all in a single email towards the end of next
week.  I have also made a doodle for the next meeting, which I suggest
we hold mid-August (I realize many of you will be on break):

That meeting will run from 4-5pm Europe Summer time.  The doodle site
should allow you to see the time in your own time zone.


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