IPB

Welcome Guest ( Log In | Register )

15 Pages V  < 1 2 3 4 > »   
Reply to this topicStart new topic
The power of HiRISE
Nirgal
post Dec 1 2008, 10:49 PM
Post #16


Member
***

Group: Members
Posts: 711
Joined: 30-March 05
Member No.: 223



QUOTE (hendric @ Dec 1 2008, 11:33 PM) *
There was some concern before that HiRise's resolution would actually be greater than the Mars atmosphere would allow due to twinkling. Has anyone taken a look at that again? What's the new maximum theoretical resolution from orbit? Less than 5cm?


I don't know the exact numbers but from looking at many hundreds of HiRise image it does "feel" like the highest resolution level indeed lacks some of the "crispness" of the larger scale zoom levels ... don't know if this is due to atmosphere twinkling or other optical and/or image processing effects though ....
Go to the top of the page
 
+Quote Post
Guest_Sunspot_*
post Dec 2 2008, 09:08 AM
Post #17





Guests






The camera developed a fault not long after science operations began. There has been an obvious deterioration in image quality as a result - images are much grainier and not as crisp.

Look at this first picture obtained of Spirit at Home Plate


Attached thumbnail(s)
Attached Image
 
Go to the top of the page
 
+Quote Post
SteveM
post Dec 2 2008, 02:44 PM
Post #18


Member
***

Group: Members
Posts: 236
Joined: 5-February 06
Member No.: 675



The reported degradation of the camera has been found to be minimum in past discussions; see, for example:

QUOTE (tuvas @ Feb 12 2007, 09:23 AM) *
That is a large exaggeration. Channel 1 of IR10 almost has completely stopped working, but channel 0 is working just fine. Looking at the articles that have been posted, I would point you to the space.com article and state that it seems to be the most informative and accurate, except for it's title. Quoting two parts of it which are totally true:

QUOTE
In late November 2006, the HiRISE team noticed a significant increase in noise, such as bad pixels, in one of its 14 camera detector pairs. Another detector that developed the same problem soon after MRO’s launch in August 2005 has worsened. Images from the spacecraft camera last month showed the first signs of this problem in five other detectors.


QUOTE
That warming, McEwen told SPACE.com, is sufficient to reduce the HiRISE problem to minor dropouts—easily interpolated—in RED 9, and no problems at all in other charge couple devices within the instrument except an infrared receiver channel (IR10 channel 1), where instrument specialists first saw this problem after MRO’s blastoff from Florida in August 2005.

These two statements are 100% correct. Just thought I'd point that out.

and

QUOTE (remcook @ Aug 27 2007, 04:45 AM) *
http://www.spaceflightnow.com/news/n0708/26mro/

"Alfred McEwen of the University of Arizona, Tucson, principal investigator for the camera, said, "I'm happy to report that there has been no detectable degradation over the past five months." "

"McEwen said, "Given the stability we've seen and understanding the nature of the problem, we now expect HiRISE to return high-quality data for years to come." "

yay!

Steve M
Go to the top of the page
 
+Quote Post
Stu
post Dec 10 2008, 02:39 PM
Post #19


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



Hey, look... HiRISE is on Twitter now, too...

http://twitter.com/HiRISE



--------------------
Go to the top of the page
 
+Quote Post
lyford
post Dec 10 2008, 04:18 PM
Post #20


Senior Member
****

Group: Members
Posts: 1260
Joined: 18-December 04
From: San Diego, CA
Member No.: 124



A picture is worth 140 characters!


--------------------
Lyford Rome
"Zis is not nuts, zis is super-nuts!" Mathematician Richard Courant on viewing an Orion test
Go to the top of the page
 
+Quote Post
Stu
post Dec 11 2008, 08:46 PM
Post #21


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



Just... beautiful... ohmy.gif ohmy.gif ohmy.gif

Capri Chasma images


--------------------
Go to the top of the page
 
+Quote Post
OWW
post Dec 11 2008, 09:01 PM
Post #22


Member
***

Group: Members
Posts: 690
Joined: 28-September 04
Member No.: 99



QUOTE (Sunspot @ Dec 2 2008, 10:08 AM) *
The camera developed a fault not long after science operations began. There has been an obvious deterioration in image quality as a result - images are much grainier and not as crisp. Look at this first picture obtained of Spirit at Home Plate


Many of the recent images are very noisy indeed. Others however, are still very good. This image of Gusev was taken just three months ago.
http://hirise.lpl.arizona.edu/PSP_010097_1655

Attached thumbnail(s)
Attached Image
 

Attached image(s)
Attached Image
 
Go to the top of the page
 
+Quote Post
akuo
post Dec 11 2008, 10:20 PM
Post #23


Member
***

Group: Members
Posts: 435
Joined: 24-March 04
From: Finland
Member No.: 63



AFAIR the noise problem was present only in some of the CCDs in Hirise's CCD array. Also the problem was remedied somewhat by warming(?) the CCDs.

I think the atmospheric conditions on Mars play a bigger role. That could be seen in some of the images taken during the major dust storm around rovers' regions.


--------------------
Antti Kuosmanen
Go to the top of the page
 
+Quote Post
Stu
post Dec 21 2008, 07:09 PM
Post #24


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



Inbetween writing Christmas cards and eating mince pies today I've been playing about with the wonderfully addictive website http://global-data.mars.asu.edu that lets you explore Mars through the eyes of spaceprobes from Viking to MRO. I like just dipping in at random, playing a kind of "martian lucky dip" if you like, and seeing what turns up. I just found something interesting... well, I think it is.

Image http://hirise.lpl.arizona.edu/PSP_005665_1800 is entitled "Change detection in Dark spot", so I thought it was worth a look... change is always a good thing on Mars, after all... into IAS Viewer and fine, looked just like one of those "fresh impact craters" to me - a dark "splash" of colour on a bright background. Zoom - and yep, right in the centre there's a small cluster of craters. But that's not what caught my eye - what made me go "hmmm" were the many dark lines and trails coming off the terrain around it. There are hundreds of them! I'm just puzzled what I'm seeing... this isn't a polar area, so the light terrain can't be frost- or snow-covered, yet it looks like something is coming out from underneath a surface layer..?

Attached Image


Anyway, just thought it was interesting - note: not odd, interesting! - and wondered if anyone has any thoughts about it.

HiRISE. What a fantastic camera! smile.gif



--------------------
Go to the top of the page
 
+Quote Post
ElkGroveDan
post Dec 21 2008, 07:11 PM
Post #25


Senior Member
****

Group: Admin
Posts: 4636
Joined: 15-March 05
From: Sloughhouse, CA
Member No.: 197



Stu, do those lines appear throughout the region or just in the immediate proximity to the new craters?


--------------------
If Occam had heard my theory, things would be very different now.
Go to the top of the page
 
+Quote Post
Stu
post Dec 21 2008, 07:16 PM
Post #26


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



QUOTE (ElkGroveDan @ Dec 21 2008, 07:11 PM) *
Stu, do those lines appear throughout the region or just in the immediate proximity to the new craters?


Best to take a look yourself Dan... they're more common close to the craters I think, but not exclusive to the immediate area.


--------------------
Go to the top of the page
 
+Quote Post
OWW
post Dec 21 2008, 09:27 PM
Post #27


Member
***

Group: Members
Posts: 690
Joined: 28-September 04
Member No.: 99



They look like ordinary dry dust avanches.
Go to the top of the page
 
+Quote Post
imipak
post Dec 21 2008, 09:28 PM
Post #28


Member
***

Group: Members
Posts: 643
Joined: 23-December 05
From: Forest of Dean
Member No.: 617



Fascinating, good catch, I'm looking forward to finding out what on Mars it is... unsure.gif

Edit: OWW - thanks!


--------------------
--
Viva software libre!
Go to the top of the page
 
+Quote Post
Stu
post Dec 21 2008, 09:37 PM
Post #29


The Poet Dude
****

Group: Moderator
Posts: 5548
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



QUOTE (OWW @ Dec 21 2008, 09:27 PM) *
They look like ordinary dry dust avanches.


Exactly what I thought... wasn't suggesting anything else... just thought it was an interesting area and thought others might think so, too. Still a bit puzzled by the process tho... there are an awful lot of them, and they do look like they're coming from beneath a surface layer of some kind, to my eye at least. But I'm no geologist, obviously.


--------------------
Go to the top of the page
 
+Quote Post
OWW
post Dec 21 2008, 09:58 PM
Post #30


Member
***

Group: Members
Posts: 690
Joined: 28-September 04
Member No.: 99



Me neither. smile.gif
But I don't see any layers. To me, it looks like they all begin at the top of the 'plateaus'.
Go to the top of the page
 
+Quote Post

15 Pages V  < 1 2 3 4 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 18th April 2014 - 11:35 PM
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 a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.