\input a4_11.ltx
\input mypdfbr.lt
\input myhtml.lt
\usepackage{graphicx}

\newcommand{\ing}[1]{

\noindent\includegraphics[width=\columnwidth]{#1}
}

\pagestyle{empty}
%\footskip=8mm


\begin{document}

\title{\vspace{-3cm}Report on 2006 activities 
of the \wwwt{Czech Section}{http://www.astro.cz/darksky} \\
 of the \wwwt{International Dark Sky Association}{http://darksky.org} }
\author{\wwwt{Jan Hollan}{http://amper.ped.muni.cz/jenik}}
\date{September 13, 2007 (supplemented Sep 20)}

\maketitle
\thispagestyle{empty}
\enlargethispage{10mm}

\begin{htmlonly}
\tableofcontents
\end{htmlonly}

\sloppy

\vspace{-1cm}
\section{Summary}

In 2006, the Czech section of the IDA worked on research mostly, but 
two new educational activities, based on images of night  scenes and
their description emerged, with participation of dozens of authors. Of
course, most outputs are available in Czech only. (Let's remember our
main info in English is at \h{www.astro.cz/darksky}, and that the
previous Section reports are  within \amper{light/ida}). As in the years
before, Czech section made no financial operations, being but a 
collaborating group of people.

\section{Research and its results}

\subsection{National Park at Night}

Two new ski slope lighting installations within
Giant Mountains (Czech: Krkono�e, German:
Riesengebirge; \h{www.krnap.cz/en/}) National Park have been 
investigated. The report for the Park Administration was 
issued in June and is accessible in full extent within
\amper{noc/krnap/2006}.

2006 and 2005 results regarding \emph{Skiing at night}
were summarised within an article for an 
environmental magazine Veronica 
(No�n� ly�ov�n�, Veronica 2006/3, p. 12-13). A non-abbreviated Czech 
text from May is accessible as 
\amper{noc/krnap/2006/lyzovani_v.htm}.


\subsection{Digital imaging photometry}

The employed photometry method, further developed during 2006,
has been presented (including examples esp. from the 
Giant Mts. Park) on the IAU congress in Prague in August, within the 
\wwwt{Commission 50}{http://www.ctio.noao.edu/light_pollution/iau50/} 
(Protection of Existing and 
Potential Observatory Sites) meeting: 
\emph{Digital imaging photometry with common cameras --
   results, methods and perspectives}
(\amper{light/lectures/06IAU50t_small.pdf}, 8~MB lecture slides by J. 
Hollan; a 21~MB full resolution version is there too).

During autumn, the method was described in detail in Czech and presented 
on a workshop Non-destructive testing:
RGB radiometrie digit�ln�mi
   fotoapar�ty (RGB radiometry by digital cameras). 
   In Workshop NDT 2006. Brno : Brno University of 
Technology,
   2006. p. 31-37. ISBN 80-7204-487-7. See 
\amper{light/luminance/czech/} (files rgb.*, or directly the
\wwwt{pdf version}{http://amper.ped.muni.cz/light/luminance/czech/rgb.pdf}). 

\subsection{Continuous measurement of outdoor light}

A new realm has been opened by creating a system 
of continuous measurement of light at Brno Observatory. As a detector, a 
small photovoltaic panel is used. The measurement began shortly after the
summer solstice 2006, so now we have more than one year of 
continuous data and plots. Tom� Mil�� and the Faculty of Education 
were the motors to make it happen. A software to plot natural light 
clear-sky illuminances was written with help of a priv. comm. by Paul 
Schlyter. See the results at \amper{weather}. 

The modern reality that clouds make the night in towns brighter 
instead of darker, is very apparent in our series. 2 km 
from the city centre, the horizontal illuminance can go up by one order of 
magnitude, from 0.02~lx to 0.3~lx, or even to 1~lx with snow.

I know about no other series like that. That of ours is supplemented by 
standard meteo data since August 2006; it illustrates nicely how the 
air cools down more quickly on clear nights (or clear moments at night).

\subsection{Measuring luminance of small 
\wwwt{solid angles}{http://en.wikipedia.org/wiki/Solid_angle} with SQM}

The first cheap instrument for measuring nightime luminances has 
been introduced to the market in 2005 -- the \wwwt{Sky Quality 
Meter}{http://www.unihedron.com/projects/darksky/}. It's excellent for 
measuring luminance of large space angles (almost 2$\pi$, i.e. a 
\wwwt{half-space}{http://en.wikipedia.org/wiki/half_space}) if it is  
uniform --  almost the case of a clear natural moonless night
sky.  However, in many cases this condition is not met.  In January,  a
\wwwt{uses of SQM and how to 
re-calibrate}{http://amper.ped.muni.cz/jenik/letters/radiometry/msg00015.html} 
posting described how to use it with a baffle to measure much lower
solid  angles, with a considerable  decrease of sensitivity however.  In
November, I've demostrated an adaptation of the instrument,
lowering the sensitivity by some 20~\% only, see \wwwt{a
glass-ball collimator for SQM}
{http://amper.ped.muni.cz/jenik/letters/radiometry/msg00021.html} (a 
better lens is recommended at its end). Uneven luminance
within that small solid angle might then be a problem, easy to
reveal by repeated measurements (rotating the SQM or changing its bearing 
slightly). 


\section{Education}

 My lecture on the protection of night environment was included into 
courses on two other universities in 2006, besides I gave two other
lectures. Pavel Suchan had a seminar for teachers ``Is  there enough
darkness for the nature?'', an article in magazine EKO, a
lecture, and a radio programme. LP has been included within the
Astronomical Olympiad. Another authors published too.

The Czech Astronomical Society has issued a very nice 
\wwwt{small brochure on LP}
{http://www.ian.cz/redsys/upload/477-Letacek_Svetlo_a_tma_2006-04-28.pdf}
(2 MB).

Its West-Bohemian branch organised a 
photographic competition. A huge amount of contributions came, 
the winning ones (Czech described) see at 
\h{www.astro.zcu.cz/cs/clanky/svetlo/4/}, a broader selection
\www{here}{http://www.astro.cz/galerie/v/projekty/fotosoutez/svetelne_znecisteni/fotografie_vybrane_komisi/}
 and all contributions
\www{here}{http://www.astro.cz/galerie/main.php?g2_itemId=8255}.

Just before the end of 2005, Jan Kondziolka started a 
\emph{series based on commented images}
within ``Instant astronomical news''. By August 2007 it had 36
issues, see \h{ian.cz/index_ser.php?id=6}. 

For the educational portal of Masaryk Uni in Brno I wrote
an article Night and Day Once and Today (Noc a den kdysi a dnes, 
see within \amper{noc/a_den/}), a good candidate to be 
translated into English.

\enlargethispage{2cm}

\section{Recommendations}

For my own city, I wrote an article Night environment in Brno, its Czech 
text see \amper{light/texty_html/noc_prob.html}. 

In autumn 2006 I was invited to collaborate (as a stakeholder) on an 
European study on streetlighting. It was too late to affect the study 
significantly. Selected letters to the 
study's authors are within 
\amper{light/EuP/}. After taking part at the stakeholder meeting in 
Bruxelles on Dec 18, and identifying what needs to be done, I wrote a 
series of texts, the principal one being on what the Light 
Pollution is indeed. The first version was published before the end of 
the 2006, the current one is expanded, see  
\amper{light/lp_what_is.pdf} or
\amper{light/lp_what_is.htm}. Even if we might think that everybody 
somehow knows what is LP, this is not the case. The only scientific 
definition has been mentioned by Pierantonio Cinzano in one of his 
articles, now it is contained in some laws too. I've 
elaborated his definition into a fully quantitative and applicable 
system. Lack of any such system has been the very cause, why Light 
Pollution was almost ignored in that study, and definitely not used as it 
should be, namely as the main environmental aspect of streetlighting.

The directory
\amper{light/EuP/} contains several other texts on vital aspects of 
streetlighting, namely on relevant luminaire parameters, on 
technologies to achieve full shielding, on antireflection coatings 
(with cost below 10 euro per square metre). But these were written in 
2007 only... Similarly, the needed development of ies2tab programme 
took place in early 2007 (\amper{light/ies2}).


\end{document}


