[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[DSLF] Digest Number 1046
_________________________________________________
To subscribe to the DarkSky List Forum send email
to: DarkSky-list-subscribe@yahoogroups... or visit:
http://groups.yahoo.com/group/DarkSky-list/join
Help save your town from obtrusive lighting --
Invite your Planning and Zoning department and
local officials to join us! Please visit the IDA
website at http://www.darksky.org frequently, too!
------------------------------------------------------------------------
There are 8 messages in this issue.
Topics in this digest:
1. Ski resort lighting: NH
From: "mike pelletier" <mikpel@hotmail...>
2. Asphalt roads are not black
From: Jan Hollan <jhollan@amper....muni.cz>
3. Fireworks
From: Jan Hollan <jhollan@amper....muni.cz>
4. Re: Ski resort lighting: NH
From: "ctstarwchr" <ctstarwchr@aol...>
5. RE: Ski resort lighting: NH
From: "J. Delvin Armstrong, P.E." <del@softlite...>
6. RE: Another LP Law on the books for CT
From: "Fitzpatrick, Eric (J.)" <efitzpat@visteon...>
7. RE: Re: Ski resort lighting: NH
From: "Friedel PAS" <friedel.pas@bvpartners...>
8. Re: Ski resort lighting: NH
From: "James Benya" <jbenya@benyalighting...>
________________________________________________________________________
________________________________________________________________________
Message: 1
Date: Tue, 17 Jun 2003 09:28:24 -0400
From: "mike pelletier" <mikpel@hotmail...>
Subject: Ski resort lighting: NH
Hi, I just call a call from Tenney Mountain Ski & Snowboard Resort in
Plymouth, NH. They are going to put up lights for night skiing and wanted
to know if there are any recommendations. I could find none, except for
keeping the light pointed at the ground (snow) and to not to use too much
illumination on the ground... but how much is too much in footcandles?
Any ideas?
The reason they called NHCRL was because a Walmart recently moved into their
town and their were concerns/problems with outdoor lighting and the town had
no ordinance but is considering one now.
Mike in NH
_________________________________________________________________
Protect your PC - get McAfee.com VirusScan Online
http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
________________________________________________________________________
________________________________________________________________________
Message: 2
Date: Tue, 17 Jun 2003 16:30:35 +0200 (CEST)
From: Jan Hollan <jhollan@amper....muni.cz>
Subject: Asphalt roads are not black
Short time ago I realized one simple thing regarding albedos and yesterday
made some search on Internet, with not many results. But still some
(http://eande.lbl.gov/HeatIsland/PUBS/2000/43442rep.pdf gives road albedos
for solar radiation, visual ones may be a bit lower).
Asphalt roads are not black at all as a rule -- just look around!
There is a possibility of vast reduction of installed power (or of dimming
2x and more in the evening already), as the real (in vast majority, more
than 3 years old) asphalt streets and roads are far brighter than those 7
or 10 per cent. The typical albedo is perhaps 12 per cent, 15 being quite
common as well, or even more. Specular reflectivity is high in general
and the more in the very polished paths of tyres. Unlike for fresh
asphalts (still covering the whole grains and unbleached by sunshine).
The posibility of using much fainter illumination holds whenever the
luminance is the important value (and partly even if the true illuminance
of the pedestrians and of any objects on the street matters), not just the
direct illuminance by the luminaires. The knowledge of albedos (and, if
possible, even of BRDFs) of real roads is much needed, do you know any?
The high albedo of asphalt is very apparent whenever there are wet patches
on it -- just they can be black, i.e., with absorptivity well over 0.90,
like the absorbers of solar collectors (we painted a couple of absorbers
with asphalt paint years ago, but within a year they became greenish and
some years later the paint layer decayed to a bit of dust).
In case a new asphalt is put on the street, it's so expensive that
changing the lamps and ballasts can be made temporarily for the nearest
year as well, than back again. However, the current trend is just the
opposite. To reduce the urban heat island effect, the top layer of asphalt
is stripped off and replaced by a rather white cement concrete... then the
lamp wattage can be reduced still twice or thrice more.
Apropos, large-amplitude dimming should be always steered by a sensor of
the luminance of the road, not just by guessing the suitable effective
voltages. It would use more light when the road is wet and therefore
dark (and the people see worse probably even because of raindrops), and
much less light if it is snow-covered.
cheers,
jenik
PS.
I've put a grayscale-making PostScript code on
http://amper.ped.muni.cz/light/luminance
-- the albedos of paper and paint can be changed at its beginning.
However, for low albedos the 600DpI printers have no sufficient
resolution, so asphalt is beyond the scope of this method.
________________________________________________________________________
________________________________________________________________________
Message: 3
Date: Tue, 17 Jun 2003 16:34:56 +0200 (CEST)
From: Jan Hollan <jhollan@amper....muni.cz>
Subject: Fireworks
The issue of fireworks has been risen by an experienced biologist and
painter Jan Dungel, a friend of mine, in Sunday.
At first I answered as usually that fireworks are not among the most
serious sources of light pollution, as they are neither so strong nor so
lasting as outdoor luminaires.
Still, should not we try to forbid fireworks in the periods when the birds
are nesting? They make them to abandon the nests, both due to puzzling
light and to the horrible detonations.
It's not only light pollution (and, as a such, it would be exempted from
an usual general regulation on the ground of its short duration), but it
perfectly matches the broader goal of the protection of the night
environment, and it shares the exponential rise with the light pollution.
Forbidding fireworks in these months is the minimum demand. Another could
be of course to limit their noise in general and to forbid making them
after 10 pm (perhaps with the only exception of New Year start).
A quick survey on the Net gave me some responses concerning just noise
and mostly pets, some concrete ones are on a firework bill passing the
House in the UK in Friday:
http://www.rspca-westhatch.co.uk/Newsletter.htm
and the most informative one
BAN FIREWORKS - Ban The Bang Campaign - To Protect our Animals and Wildlife
http://www.looking-glass.co.uk/campaigns/banthebang_intro.htm
The decrease of some bird populations in urbanised areas may be attributed
to fireworks as well as to general light pollution, both causes have not
been investigated yet as far as I know.
There are even more reasons to oppose fireworks, as disasters due to the
stores of explosives, or poisonous products of using them. But the general
framework of the ecology of the night is the one which should suffice.
jenik
________________________________________________________________________
________________________________________________________________________
Message: 4
Date: Tue, 17 Jun 2003 15:41:50 -0000
From: "ctstarwchr" <ctstarwchr@aol...>
Subject: Re: Ski resort lighting: NH
--- In DarkSky-list@yahoogroups..., "mike pelletier" <mikpel@h.....>
wrote:
>
> Hi, I just call a call from Tenney Mountain Ski & Snowboard Resort
> in Plymouth, NH. They are going to put up lights for night skiing
> and wanted to know if there are any recommendations. I could find
> none, except for keeping the light pointed at the ground (snow)
> and to not to use too much illumination on the ground... but how
> much is too much in footcandles?
The IES HB-99 (Chapter 20) recommends only 0.5 average maintained
vertical footcandles with 0.2 minimum vertical footcandles. No
uniformity is listed, but the directional aiming of the fixtures is
important. Since moguls and other slope features have a highly
reflective non-uniform surface they model fairly well even when
uniformity is poor. Unless dressed in white, most skiers usually
stand out pretty well.
Slopes I've skied at night (illuminated or not) were most enjoyable
and significantly more visible during moonlit nights. Illuminated
slopes offered the most visible features when luminaires were aimed
at least 45 degrees or more away from the direction of travel. I
found the greatest difficulty seeing when luminaires were aimed
perpendicular to the slope. I've never seen fcos like SofT Lighting
Systems, but it would not be out of the question if fixtures could
be mounted high enough. Double black diamond slopes in NH would
require significantly higher lighting levels if people were nuts
enough to brave them after dark. Probably best leaving them dark.
Check out the Abacus Challenger 1 sports flood (mounted on poles
high enough to allow near level installations).
http://www.lighting4sport.com/floodlightingforsport.htm
One of the biggest foibles with sports lighting is short poles. The
lower the poles, the more glare and light pollution will usually
result. Glare is best kept to a minimum in the direction of travel
for a fast sport like nighttime skiing. There will be considerable
reflected light, too, but if illuminance is kept to minimum levels
the resulting damage can be reduced to a degree, but not entirely.
Clear skies,
Cliff Haas
http://members.aol.com/ctstarwchr
http://www.crlaction.org
________________________________________________________________________
________________________________________________________________________
Message: 5
Date: Tue, 17 Jun 2003 09:59:33 -0700
From: "J. Delvin Armstrong, P.E." <del@softlite...>
Subject: RE: Ski resort lighting: NH
There is some information on lighting of ski areas in the IESNA Sports
Lighting Recommended Practice RP-6-01. We have been the Engineer of
Record on several hundred acres of ski area lighting in the Cascades
and, from a "Dark Sky" standpoint you can just forget it. The snow
reflects most of the light and it is visible for miles.
J. Delvin Armstrong, P.E. Phone: 425.885.2195
Armstrong Engineers, Inc. Phax: 425.556.9351
1840 - 130th Avenue N.E. Cell: 206.601.7312
Suite #15 Email:
del@softlite...
Bellevue, WA 98005-2245 Web:
www.softlite.com
-----Original Message-----
From: mike pelletier [mailto:mikpel@hotmail...]
Sent: Tuesday, June 17, 2003 6:28 AM
To: DarkSky-list@yahoogroups...
Subject: [DSLF] Ski resort lighting: NH
Hi, I just call a call from Tenney Mountain Ski & Snowboard Resort in
Plymouth, NH. They are going to put up lights for night skiing and
wanted to know if there are any recommendations. I could find none, except for
keeping the light pointed at the ground (snow) and to not to use too
much illumination on the ground... but how much is too much in footcandles?
Any ideas?
<SNIP><SNIP><SNIP>
________________________________________________________________________
________________________________________________________________________
Message: 6
Date: Tue, 17 Jun 2003 15:07:16 -0400
From: "Fitzpatrick, Eric (J.)" <efitzpat@visteon...>
Subject: RE: Another LP Law on the books for CT
Great work Cliff! Makes me want to visit Connecticut one day.
-----Original Message-----
From: ctstarwchr@aol...
House Bill 5686 for floodlights located within the state right of way
is now CT State Law listed under Public Act 03-210. Check it out!
We achieved two new LP Laws for Connecticut this legislative session.
http://www.cga.state.ct.us/2003/act/Pa/2003PA-00210-R00HB-05686-PA.htm
<-snip->
________________________________________________________________________
________________________________________________________________________
Message: 7
Date: Tue, 17 Jun 2003 21:42:41 +0200
From: "Friedel PAS" <friedel.pas@bvpartners...>
Subject: RE: Re: Ski resort lighting: NH
About the lighting levels I have no Idea.
The lights must be placed well on high poles and always with fixtures in
asymmetric reflectors. So it is easier to lighting a big surface without the
need to lighting up the sky.
Regards,
Friedel
---------------------------------------------------------------------
e-mail: Friedel.Pas@BVPartners...
DHL: friedel.pas@dhl...
Orion mail: Friedel.Pas@jvsorion...
---------------------------------------------------------------------
BV&Partners (Informatici)
http://www.bvpartners.be
Boterlaarbaan 323
2100 Deurne
Tel.: +32-3-320.83.74
Fax.: +32-3-320.83.79
GSM: +32-474-50.17.95
________________________________________________________________________
________________________________________________________________________
Message: 8
Date: Tue, 17 Jun 2003 15:22:02 -0700
From: "James Benya" <jbenya@benyalighting...>
Subject: Re: Ski resort lighting: NH
Mike asked
> Hi, I just call a call from Tenney Mountain Ski & Snowboard Resort in
> Plymouth, NH. They are going to put up lights for night skiing and wanted
> to know if there are any recommendations. I could find none, except for
> keeping the light pointed at the ground (snow) and to not to use too much
> illumination on the ground... but how much is too much in footcandles?"
Others have suggested IESNA documents. IESNA recommendations are
potentially too high and I suggest contacting Nancy Clanton who has
experience in Colorado with low light level ski runs. Otherwise, the fact
that every lumen bounces up from the snow makes the concept of a "dark sky
friendly night ski run" sort of an oxymoron. Like Del says, you will see it
for miles.
James R. Benya, PE, FIES, IALD, LC
Benya Lighting Design
1880 Willamette Falls Drive
Suite 220
West Linn, OR 97068
(503) 657-9157 cell (503) 519-9631
Fax (503) 657-9153
www.benyalighting.com
________________________________________________________________________
________________________________________________________________________
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/