image credit: tally o donnell...radar (nexrad), and radar data interfacing with numerical prediction...

June 2016

Longmont Astronomical

Society Newsletter Image Credit: Tally O’Donnell

Copyright © June 2016. All rights reserved. Longmont Astronomical Society.

Next LAS Meeting June 16th

"Visually and Physically Realistic Ray-

tracing Simulations of Earth, Moon,

and Sky" by Steve Albers, NOAA

Abstract:

The presentation will discuss some ray tracing (image rendering) techniques, with an emphasis on including the physical processes of visible radiation in the Earth's atmosphere and on the surface.

Bio Steve Albers received his BSc in Physics from the State Univ. of New York at Albany (1978), and MS (1986) in Atmospheric Science from the University of Oklahoma.

Between 1976 and 1977 he worked as part of the Viking Intern program connected with the Jet Propulsion Laboratory and Brown University. He did some image processing of Viking Mars Lander Images at JPL's Image Processing Laboratory as part of the Viking Lander Imaging Team. He also performed some data reduction for the Meteorology Team. In 1979 he wrote an article for Sky and Telescope about Mutual Planetary Occultations. This led to the serendipitous discovery in 1980 that Galileo actually saw Neptune in the 1600s. Steve received the R.R Newton Award from the International Journal of Scientific History in 2009 in recognition of his role.

During the summers from 1980-1985 Steve worked as a Field Meteorologist for

the North Dakota Cloud Modification Project, directing hail suppression and rain enhancement cloud seeding with a fleet of six aircraft utilizing ice nucleation seeding materials and operating an Enterprise WR-100 5cm weather radar. Between 1983 and 1985 he worked as a Research Assistant at the School of Meteorology, University of Oklahoma. His research topic was the development of a statistical severe weather forecast package. He served as a Teaching Assistant for Meteorological Measurements and did some storm chasing.

In 1994 Steve was featured in a Sky and Telescope article about image processing of solar eclipse pictures, and his photography and imaging work has appeared in numerous books and publications. Journal articles and conference presentations on diverse topics have been given.

Since 1986 Steve has worked at various NOAA facilities in Boulder, CO, including the PROFS program, Forecast Systems Laboratory, and the Earth System Research Laboratory. In this context he came on-board CIRA in 1989. His work includes extensive development and implementation of meteorological analyses of wind, clouds, temperature, and microphysical variables for the Local Analysis and Prediction System. A variety of remotely sensed and in-situ data are ingested, quality controlled, and merged in the analyses. The analyses are used for initializing NWP models and are displayed on workstations for nowcasting, and they are fielded at ESRL, other government agencies as well as private companies. He has worked on satellite image processing

Copyright © June 2016. All rights reserved. Longmont Astronomical Society. Page 2

algorithms, including photometric correction that depends on viewing geometry, as well as image processing to produce global planetary, meteorological, and geophysical maps using IDL and other display software for NOAA's Science On A Sphere TM (SOS). Steve gives SOS presentations and daily weather briefings. Steve developed a ray-tracing package to produce visually and physically realistic imagery from atmospheric and geophysical model data. He's participated in meteorological workstation and World Wide Web display software. Radar experience includes development of radar Doppler velocity de-aliasing algorithm, testing and evaluation of algorithms to be run on the Next Generation Weather Radar (NEXRAD), and radar data interfacing with numerical prediction models.

Location: The meeting will be at the IHOP Restaurant, 2040 Ken Pratt Boulevard, Longmont. Please join us for coffee, dinner, or just desert around 6 pm; the general meeting and presentation will begin at 7 pm.

Upcoming Events

June 11th 8:30 - 10:30 pm

City of Longmont Recreation at Sandstone

Ranch Visitor Center. Presentation at 8:30

followed by star party at 9:30 pm - 10:30

pm.

Planetary imaging workshop from 10:30 –

11:30 pm

June 16th 7 - 9 pm

LAS monthly meeting at IHOP, 2400 Ken

Pratt Blvd, Longmont. Presentation

"Visually and Physically Realistic Ray-

tracing Simulations of Earth, Moon, and

Sky" by Steve Albers, NOAA

June 25th 8:15 – 10:30 pm

City of Boulder and County of Boulder

Park and Open Space Departments at Hall

Ranch Shelter, one mile west of Lyons on

Hwy. 7. Presentation “Astronomy: Our

planetary neighbors” followed by public

star party.

June 25th 10:30 - 11:30 pm

Planetary imaging workshop at Hall Ranch

following the public star party.

July 14th 7:30 – 10:30 pm

Carbon Valley Star Party, 7 Park Ave.,

Firestone, CO. “Constellation of stories”

by northern Colorado story tellers

followed by presentation by LAS. Star

party begins at 9:15 pm.

July 21st 7 – 9:00 pm

LAS meeting at IHop, 2400 Ken Pratt Blvd,

Longmont. Open forum.


June Celestial Highlights

Moon

New moon: June 4th 9:01 pm First quarter: June 11th 2:11 am Full moon: June 20th 5:04 am Third quarter: June 27th 12:20 pm

Mercury

Mercury is visible very low in the northwest around 4:45 in constellation about 45 minutes before sunrise. It brightens from magnitude 0.4 to -1.5 toward the end of the month. Size is 7.8 arc sec across.

Venus

Venus is not visible this month.

Mars

Mars begins the month with an apparent

brightness of -2 and is 19 arc sec across.

At the end of the month it will be

magnitude -1.4 and will be 16 arc sec

across. It is in the constellation Libra.

Jupiter

Jupiter begins the month at -2.1

magnitude and disk size of 37 arc seconds.

By the end of the month it -1.9 magnitude

and apparent disk size of 34 arc seconds.

Assuming the longitude of the Great Red

Spot is 248° it may be seen at mid transit

at the following times this month:

June 6 10:45 pm alt 32° June 11 9:54 pm alt 38° June 13 11:33 pm alt 18° June 16 9:04 pm alt 43° June 18 10:43 pm alt 24° June 23 9:52 am alt 30° June 28 9:02 pm alt 30°

Saturn

Saturn is in lower part of the constellation

Ophiuchus. It is magnitude +0.0 in

brightness as month begins and +0.2


magnitude on June 30th. Its disk size is 18

arc seconds this month.

Uranus

Uranus is in the constellation Pisces; it is

magnitude +5.9 in brightness and its disk

is 3.4 arc sec across.

Neptune

Neptune is in constellation Aquarius. It is

magnitude 7.9 and 2.3 arc sec across.

Meteor Showers

June Bootids peak on June 26 9:36pm.

This is a class III meteor shower so may

produce strong activity on rare occasions.

Comets

Comet 2013X1 (PANSTARRS) is visible

very low in the southern sky this month.

It is predicted to brighten from magnitude

6.7 to 6.5.

Comet 81P (Wild) is visible this month in

constellation Cancer and then Leo at

magnitude 10.7 and 1.4 arc min coma.

Comet C/2014 S2 (PANSTARRS) moves

from Ursa Major to Leo; it is magnitude

11.4 and coma is 2.7 arc min.


Overhead Sky at 10 pm June 15


LAS Meeting on May 19

by Vern Raben

Vi and I were on vacation in the UK so

missed the meeting. I’ve heard from

several people who were present though

and all mentioned that it was great.

Thanks to Tally O’Donnell for chairing the

meeting!

From what I’ve heard, Dr. Dan Davis gave

an excellent presentation on

“Understanding Particles and Fields

throughout the Solar System”. His talk

recounted some of the earlier history of

LASP’s contributions to Sun-Earth (and

planetary) studies. The principal focus of

the talk was modern studies of energetic

particles and electromagnetic fields in

Earth’s cosmic neighborhood. LASP has

been playing an increasingly prominent

role in forefront studies of Earth’s

environment and LASP researchers are

using this core terrestrial knowledge to

advance planetary and astrophysical

understanding as well. Moreover, study

and understanding of the space

environment of Earth is absolutely

essential for our knowledge of “space

weather” which represents a major threat

to our modern technological society. The

presentation addressed these aspects and

concluded with a look forward to future

LASP programs and opportunities.

Dave Elmore and Tally gave an interesting

talk about the trip they made to San

Pedro de Atacama Celestial Explorations,

a destination for amateur astronomers

and site that hosts remote telescopes.

They showed everyone some terrific

astrophotos they took during their trip.

Robert Grossman gave a talk about the

dark skies near the town of Norwood,

Colorado. The community is in the

process of getting certified as a Dark Sky

Community by International Dark Sky

Association. Town ordinances have met

most of the IDA criteria; the street lights

have recently been converted to fully

shaded LED’s. There are still a few “hot

spots” that they are investigating. A local

foundation is considering providing grants

to low-income folks who could not afford

to shade their outdoor lights. They are

hoping to have some star parties this

summer and are considering doing a

“Dark Sky Festival” this summer.

Planetary Imaging Techniques:

Luminance Blending by Vern Raben

Last month I discussed some “Wavelet

Magic” to sharpen up planetary images.

This month the separate red, green, and

blue monochrome images will be

combined and enhanced using

“luminance blending” to produce a final

image.

The red, green, and blue images are

opened in Photoshop. Click on the tab for

say the “red” image and then convert it to

gray scale by selecting the following

menus “Image” -> “Mode” -> “Grayscale”

as shown below:


This is then repeated for the other two

images which are red, and green.

Now that all three are gray scale images

they can be converted to an RGB image.

Open the channels menu by selecting

“Window”->”Channels” which will bring

up the channels menu. Click on the small

down arrow on the right side of the menu

and then Select “Merge Channels”.


The “Merge Channels” menu will then

appear.

Select “RGB Color” as shown above and

then click the “OK” button.

A “Merge RGB Channels” menu will

appear. Click on each red, green, and blue

select box to be sure that the red channel

is set to the red image. Usually they are

correct but not always. Click OK.

The RGB image appears. Check the image

to see that there no color fringes. If the

planet is high up the channels are usually

well aligned. With both Mars and Saturn

being quite low in the sky this year the

channels will need to be adjusted slightly

due to atmospheric dispersion.


I leave the red channel as is and adjust the

green and blue channels. Click on the

“green” channel visibility “eye” button to

hide that channel. And then click on the

blue channel to select it.

There is slightly more blue on the top of

Saturn so we need to use cursor keys to

nudge it downward a couple pixels. Next

turn off the blue channel and turn on the

green channel.

Select the green channel and nudge it as

to correct if necessary. I didn’t need to in

this case. Click on RGB to turn all channels

back on.


Image looks fairly good at this point but l

next use the “luminance blending”

(sometimes called “luminance layering”)

technique. Normally I don’t capture a real

luminance channel; effects of

atmospheric turbulence are almost always

worse in a luminance channel because of

the wider bandwidth. I’ll use the red

channel as an artificial luminance channel

so this will be a RRGB image.

Open the original red image. In that tab

Select “Select”->”All” and then select

“Edit”->”Copy”.

Return to the RGB image. Right click on

the “Background” layer and choose “Layer

from Background”.

Create a new layer below the

“background” layer by a control-right click

on the “create new layer” icon. Select that

layer and then paste the red image we

copied previously.

Next change the layer from “Normal” to

“Color”. If the effect is too much you can

adjust by changing the opacity.

Saturn image before “luminance

blending”:

Saturn image after “luminance blending”:

Note that the ring detail comes out a bit

better as well as overall image looks

slightly better.

Image rotated north up, noise filtered,

and brightness levels adjusted

slightly:


Tally

O’Donnell

Cygnus region


Gary Garzone

Saturn

Glenn Frank


Messier 101 Galaxy

Gary Garzone

Mars on May 29

Vern Raben


Gegensheinen at Atacama

David Elmore

image credit: tally o donnell...radar (nexrad), and radar data interfacing with numerical prediction...

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