Surprised

I thought members of this ng would find it moderatly interesting how much
atmosphere they were actually looking through.
Based on the feedback I got aparently not.
www.HaimannOnline.com/Distance
--
Author of Dipperbase (www.HaimannOnline.com/DipperBase)
A Astronomy Image database, which allows upload to the web.
Currently in alpha-testing.

Cool, it looks like a lot at 75 Deg.



"Terry A. Haimann" wrote in message
news
I thought members of this ng would find it moderatly interesting how much
atmosphere they were actually looking through.
Based on the feedback I got aparently not.
www.HaimannOnline.com/Distance
--
Author of Dipperbase (www.HaimannOnline.com/DipperBase)
A Astronomy Image database, which allows upload to the web.
Currently in alpha-testing.

Cool, it looks like a lot at 75 Deg.



"Terry A. Haimann" wrote in message
news
I thought members of this ng would find it moderatly interesting how much
atmosphere they were actually looking through.
Based on the feedback I got aparently not.
www.HaimannOnline.com/Distance
--
Author of Dipperbase (www.HaimannOnline.com/DipperBase)
A Astronomy Image database, which allows upload to the web.
Currently in alpha-testing.

Terry A. Haimann wrote:
I thought members of this ng would find it moderatly interesting how much
atmosphere they were actually looking through.
Based on the feedback I got aparently not.
www.HaimannOnline.com/Distance

Whoa, whoa, whoa...! You might try checking your web logs to see how
many people loaded the page. I checked the page out, but didn't offer
any feedback because I had none to offer. Doesn't mean I wasn't
interested.

One thing that was a bit unclear on the first read-through was whether
you had taken into account the inhomogeneity of the atmosphere--that
it's denser at the bottom and thins out exponentially toward the top.
I'll take a second look...

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

Terry A. Haimann wrote:
I thought members of this ng would find it moderatly interesting how much
atmosphere they were actually looking through.
Based on the feedback I got aparently not.
www.HaimannOnline.com/Distance

Whoa, whoa, whoa...! You might try checking your web logs to see how
many people loaded the page. I checked the page out, but didn't offer
any feedback because I had none to offer. Doesn't mean I wasn't
interested.

One thing that was a bit unclear on the first read-through was whether
you had taken into account the inhomogeneity of the atmosphere--that
it's denser at the bottom and thins out exponentially toward the top.
I'll take a second look...

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

No I didn't. I'm not knowlegable on the diffrent layers of our
atmosphere. I did this purely out of curiosity.

Once you have the edges of the layers,
it wouldn't be that dificult to program that in. It occurs to me that the
layers could vary though, depending on weather conditions.

Terry


On Mon, 16 Feb 2004 16:27:20 +0000, Brian Tung wrote:

One thing that was a bit unclear on the first read-through was whether
you had taken into account the inhomogeneity of the atmosphere--that
it's denser at the bottom and thins out exponentially toward the top.
I'll take a second look...

--
Author of Dipperbase (www.HaimannOnline.com/DipperBase)
A Astronomy Image database, which allows upload to the web.
Currently in alpha-testing.

No I didn't. I'm not knowlegable on the diffrent layers of our
atmosphere. I did this purely out of curiosity.

Once you have the edges of the layers,
it wouldn't be that dificult to program that in. It occurs to me that the
layers could vary though, depending on weather conditions.

Terry


On Mon, 16 Feb 2004 16:27:20 +0000, Brian Tung wrote:

One thing that was a bit unclear on the first read-through was whether
you had taken into account the inhomogeneity of the atmosphere--that
it's denser at the bottom and thins out exponentially toward the top.
I'll take a second look...

--
Author of Dipperbase (www.HaimannOnline.com/DipperBase)
A Astronomy Image database, which allows upload to the web.
Currently in alpha-testing.

Terry A. Haimann wrote:

No I didn't. I'm not knowlegable on the diffrent layers of our
atmosphere. I did this purely out of curiosity.

You might find this useful. Astronomers use a unit called "airmass" to
describe how much air they are looking through. This value is 1.0 at
the zenith and increases toward the horizon. Somewhere around a zenith
distance of 60 degrees the airmass reaches 2, where you are looking
through twice as mush air.

Here is the simple formula (which bears some resemblance to your own work):

Airmass = 1.0/sin(alt)

A more rigorous formula is also available:

Define A = 1.0/sin(alt)

Airmass = A*(1.0-0.0012*(A*A-1.0))

Whe

alt = altitude above horizon
* denotes multiplication

Have fun.

Greg


--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools Software for the Observer:
http://www.skyhound.com/cs.html

Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html

To reply remove spleen

Terry A. Haimann wrote:

No I didn't. I'm not knowlegable on the diffrent layers of our
atmosphere. I did this purely out of curiosity.

You might find this useful. Astronomers use a unit called "airmass" to
describe how much air they are looking through. This value is 1.0 at
the zenith and increases toward the horizon. Somewhere around a zenith
distance of 60 degrees the airmass reaches 2, where you are looking
through twice as mush air.

Here is the simple formula (which bears some resemblance to your own work):

Airmass = 1.0/sin(alt)

A more rigorous formula is also available:

Define A = 1.0/sin(alt)

Airmass = A*(1.0-0.0012*(A*A-1.0))

Whe

alt = altitude above horizon
* denotes multiplication

Have fun.

Greg


--
Greg Crinklaw
Astronomical Software Developer
Cloudcroft, New Mexico, USA (33N, 106W, 2700m)

SkyTools Software for the Observer:
http://www.skyhound.com/cs.html

Skyhound Observing Pages:
http://www.skyhound.com/sh/skyhound.html

To reply remove spleen

Greg Crinklaw wrote:

Terry A. Haimann wrote:

No I didn't. I'm not knowlegable on the diffrent layers of our
atmosphere. I did this purely out of curiosity.


You might find this useful. Astronomers use a unit called "airmass"
to describe how much air they are looking through. This value is 1.0
at the zenith and increases toward the horizon. Somewhere around a
zenith distance of 60 degrees the airmass reaches 2, where you are
looking through twice as mush air.

^^^^^

Freudian slip?







--
------

Rick S.

http://users.rcn.com/rflrs