IPB

Welcome Guest ( Log In | Register )

34 Pages V  « < 32 33 34  
Reply to this topicStart new topic
LROC news and images
Sean
post Nov 29 2017, 01:01 PM
Post #496


Member
***

Group: Members
Posts: 923
Joined: 10-November 15
Member No.: 7837



Here are a couple of videos... I eyeballed the sun angle so I wonder how wrong the shadow direction is!

Sunset on Clavius


Sunset on Tycho


--------------------
Go to the top of the page
 
+Quote Post
Sean
post Dec 1 2017, 09:28 PM
Post #497


Member
***

Group: Members
Posts: 923
Joined: 10-November 15
Member No.: 7837



Moon High... 60 Megapixel portrait rendered from LROC data


Detail 001



Detail 002






--------------------
Go to the top of the page
 
+Quote Post
Sean
post Dec 6 2017, 06:08 PM
Post #498


Member
***

Group: Members
Posts: 923
Joined: 10-November 15
Member No.: 7837



Here is a video made from LRO data...



4k60 Youtube version



--------------------
Go to the top of the page
 
+Quote Post
antipode
post Jan 11 2018, 11:07 PM
Post #499


Member
***

Group: Members
Posts: 314
Joined: 1-October 06
Member No.: 1206



I'll add this to this thread because if its confirmed it might make the case for polar exploration even more interesting.

Skylights in the polar regions have been lacking up til now I think.

https://seti.org/seti-institute/press-relea...north-pole-moon

P
Go to the top of the page
 
+Quote Post
Sean
post May 22 2018, 06:08 PM
Post #500


Member
***

Group: Members
Posts: 923
Joined: 10-November 15
Member No.: 7837



Some new flyby clips on Flickr... full length versions at the Youtube link...


Full 3 minute 4k60 Youtube version


Full 3 minute 4k60 Youtube version


Full 3 minute 4k60 Youtube version


Full 1 minute 4k60 Youtube version


--------------------
Go to the top of the page
 
+Quote Post
GoneToPlaid
post Feb 25 2019, 06:25 AM
Post #501


Junior Member
**

Group: Members
Posts: 31
Joined: 24-February 17
From: California
Member No.: 8127



Sean, I love the image of the Apennines and the Apollo 15 landing site!
Go to the top of the page
 
+Quote Post
scalbers
post Feb 25 2019, 10:46 PM
Post #502


Senior Member
****

Group: Members
Posts: 1620
Joined: 5-March 05
From: Boulder, CO
Member No.: 184



Thanks for posting some new animations to enjoy. Might be something outside your workflow, though it might look neat to try and add in some opposition effect if you're looking in the direction opposite the sun. It's hard for me to find an example of this (from orbit) for the moon, so I'll substitute one from the Hyabusa 2 spacecraft instead:

http://www.hayabusa2.jaxa.jp/en/topics/201...TD1R1A_W1movie/


--------------------
Steve [ my home page and planetary maps page ]
Go to the top of the page
 
+Quote Post
Sean
post Feb 26 2019, 12:24 AM
Post #503


Member
***

Group: Members
Posts: 923
Joined: 10-November 15
Member No.: 7837



Thanks, I've noticed this quite a bit when working with ISS sequences.


--------------------
Go to the top of the page
 
+Quote Post
scalbers
post Feb 26 2019, 12:54 AM
Post #504


Senior Member
****

Group: Members
Posts: 1620
Joined: 5-March 05
From: Boulder, CO
Member No.: 184



Indeed it's important on the Earth as well, where at least the core of this effect might be modeled with a simple phase function. I like your last animation posted above with pretty convincing changing shadows at sunrise.


--------------------
Steve [ my home page and planetary maps page ]
Go to the top of the page
 
+Quote Post
GoneToPlaid
post Feb 26 2019, 02:32 AM
Post #505


Junior Member
**

Group: Members
Posts: 31
Joined: 24-February 17
From: California
Member No.: 8127



QUOTE (scalbers @ Feb 25 2019, 02:46 PM) *
Thanks for posting some new animations to enjoy. Might be something outside your workflow, though it might look neat to try and add in some opposition effect if you're looking in the direction opposite the sun. It's hard for me to find an example of this (from orbit) for the moon, so I'll substitute one from the Hyabusa 2 spacecraft instead:

http://www.hayabusa2.jaxa.jp/en/topics/201...TD1R1A_W1movie/


This is the heiligenschein effect which is caused by very tiny glass beads in the regolith. The glass beads are created by micrometeorite bombardment. The same of course is seen in Apollo orbital and EVA photos. The Hapke parameters could be reversed to create the heiligenschein effect, based in solar incidence angle versus emission angle.
Go to the top of the page
 
+Quote Post
scalbers
post Feb 26 2019, 06:31 PM
Post #506


Senior Member
****

Group: Members
Posts: 1620
Joined: 5-March 05
From: Boulder, CO
Member No.: 184



I had thought heiligenschein was mainly associated with dewy grass on Earth - interesting that this also applies to glass beads on the moon.

I think a more general opposition surge phenemenon can happen with a greater variety of compositions, including dry grass on Earth or dry dust as well.

Yes the Hapke terms (related to the notion of bi-directional reflectance distribution function - BRDF, or anisotropic reflectance factor - ARF) would be a more complete treatment. A quick approach might be a simple ARF using phase angle only that could be a correction to be multiplied by the original image.


--------------------
Steve [ my home page and planetary maps page ]
Go to the top of the page
 
+Quote Post
GoneToPlaid
post Mar 2 2019, 03:18 AM
Post #507


Junior Member
**

Group: Members
Posts: 31
Joined: 24-February 17
From: California
Member No.: 8127



QUOTE (scalbers @ Feb 26 2019, 10:31 AM) *
I had thought heiligenschein was mainly associated with dewy grass on Earth - interesting that this also applies to glass beads on the moon.

I think a more general opposition surge phenomenon can happen with a greater variety of compositions, including dry grass on Earth or dry dust as well.

Yes the Hapke terms (related to the notion of bi-directional reflectance distribution function - BRDF, or anisotropic reflectance factor - ARF) would be a more complete treatment. A quick approach might be a simple ARF using phase angle only that could be a correction to be multiplied by the original image.


Dewy grass is the most obvious. Yet of course, other things also can create heiligenschein.

Sean's works are amazing to watch. If he does decide to try anything, I agree that a simple ARF method would be the way to go, as it should be more than good enough to simulate the lunar heiligenschein effect. I don't think that he needs to be precise about it either. Doing calculations for a simple sphere, ignoring the actual terrain, probably would suffice nicely.

Yet even slicker would be if Sean would add a global calibrated WAC color image overlay. The WAC filter numbers which best represent RGB are filters 7, 4 and 3 (listed in order of RGB). Following is a chart I made which shows the bandpasses of the WAC filters. As you can see, the blue filter #4 really is violet. I always end up having to perform a bit of a hue shift for blue when creating color WAC images in order to more accurately simulate what the human eye would see.
Attached thumbnail(s)
Attached Image
 
Go to the top of the page
 
+Quote Post
atomoid
post Sep 10 2019, 12:57 AM
Post #508


Member
***

Group: Members
Posts: 866
Joined: 15-March 05
From: Santa Cruz, CA
Member No.: 196



New release of LRO data for 3D imaging CGI Moon kit, surely to come in handy for all that free time i don't have
Go to the top of the page
 
+Quote Post
Sean
post Sep 10 2019, 09:17 AM
Post #509


Member
***

Group: Members
Posts: 923
Joined: 10-November 15
Member No.: 7837



Too much data! Not enough time!

Thanks for the input guys... I'll be sure to reference on my next trip to the Moon.


--------------------
Go to the top of the page
 
+Quote Post
JRehling
post Sep 10 2019, 02:22 PM
Post #510


Senior Member
****

Group: Members
Posts: 2530
Joined: 20-April 05
Member No.: 321



Funny little mnemonic in the terminology: Heiligenschein is German for "holy shine" and it is noticeable when you see the shadow of your own head in dewy grass and your head's shadow appears to be surrounded with a glowing halo, hence the angelic association. Of course, in that circumstance, your head itself always blocks out what would be the most intense location of the effect.

I'm hoping for good skies this year when Uranus is in opposition to see if I can use this to get a picture of Uranus' rings – fingers crossed. I'm pretty sure in that case I don't have to worry about the shadow of my head, or the Earth.
Go to the top of the page
 
+Quote Post

34 Pages V  « < 32 33 34
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 19th March 2024 - 03:50 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.