From
Eric
NG
® . . . . . .Subject: Re: RE:Reprocessed
20030522
Mars
Dear Minami,
Thank you for your kind email and thank you for your kind comment.
In fact the images previously I sent were taken without IR blocking filters and
each RGB channels were seriously "polluted" by the IR. The effect was
even worse due to atmospheric dispersion that leading to the "ghost"
IR on G and B frame. Attached image was taken this morning, seeing and transparency were poor. However, this one was taken with IR
blocker and the RGB frames already improved a lot.
Actually, I have been discussing with Tan Wei Leong of
Yes. The rush version of my 20030522 Mars seems
over-processed and also the IR ghost may generate the "fake" details.
Kind Regards,
(27 May 2003
® . . . . . .Subject: 20030529 Mars observation
Dear friends,
The sky finally clear but very
hazy. I have to gain 60% for 1/25 sec at F34. I split the Mars into RGB
components so that you can review some features in different colour channels.
The Solis Lacus is visible and the region of Mare Erythraeum and Aurorae Sinus
can be seen near the CM. Nilokeras is bright. Some dark
region on the south polar cap. No hints of dust activity on the image.
http://www.ort.cuhk.edu.hk/ericng/mars_200305292122_eric.jpg
Please kindly comment.
Regards,
(30 May 2003
email)
® . . . . . .Subject: Re: RE:20030529 Mars observation
Dear Masatsugu,
Thank you so much for your kind and prompt reply. I always
can learn the invaluable knowledge from your expert comment.
Yes. The blue channel is tailed in green so the B frames
contains some signal of green though it is weak. But I would say the B frame after
the IR blocked already quite close to the one taken through interference filter
with cooled CCD. As you may know that the transparency was very poor when I was
imaging in this morning, the hazy sky absorbed the blue quite much that leading
poor SN of Blue. Also the thermal noise seems has effect on it (today 31 degree
C). I will use the modified cooled ToUcam Pro shortly.
We will try our best to tackle the B frame problem. We are
testing some different method with Wei Leong. Will show you the result. heheh.
As I am not that experience in describing Mars, all my comment is in newbie
tone. ^_^ I compare my image with the Mars Map and I just found the region
between the Nilokeras and Niliacus Lacus is light. I
am not sure whether I am correct or not.
I just got my 12.5" F6 mirror. The setup will be
completed in mid June. I will move to my rural observing site for 3 months Mars
observation where the seeing is much better than my home roof in the center of
city. Now I only have 45 mins for imaging Mars as it
is being blocked by the high rise building which is as high as 45 degree from
horizon.
Cheers,
(30 May 2003
®. . . . . .Subject:
20030530 Mars in this morning
Dear friends,
Attached was the Mars image taken on 20030530 this morning.
Both seeing and transparency were poorer than yesterday. I had to gain 80% at
1/25 sec with ToUcam Pro. I needed to stack 1000 frames out of 1700 to achieve
acceptable SN. I tried the B-(GX0.3) method introduced by KUMAMORI and found
that it did help very much in aligning the RGB components and no visible
dispersion effect after realignment. As the B frame contains the some G signal,
so the blue colour fringes usually appear out of the north edge ... After
applied KUMAMORI's method, the misaligned blue
fringes will align back with R and G which is actually the detail of haze hood
above North polar region. Thanks the information by Damian.
http://www.ort.cuhk.edu.hk/ericng/mars_200305302114_eric.jpg
Minami, my image is not high resolution enough. Seems the
dust storm you have mentioned is not visible well in my image. Please kindly
comment,
Clear Skies,
(31 May 2003
® . . . . . .Subject: Another 20030530 Mars
Dear friends,
Here is the image taken at 20:39UT. The seeing was slightly
better. Meridiani Sinus is visible near p.
limb. SN ration of blue frame is especially poor due to low transparency
Minami, the dust streak you mentioned seems better shown in
this picture.
http://www.ort.cuhk.edu.hk/ericng/mars_200305302039_eric.jpg
Kind Regards,
(31 May 2003
® . . . . . .Subject: Re: RE:20030530 Mars in this morning
Dear Minami,
Hehe.
Thank you. The sky will be clear in coming few days but just will be very very hazy. I will try my best to obtain good result.
Kumamori's
method is the way I can do better before I get the interference filter for
getting better Blue. We will keep posting the results to you. I would say if I
used cooled CCD for today situation, I believe the Mars would be blur and no
details visible on the Globe.
If the transparency is good, I believe the B frame would
have better SN. Let's keep see the result. Moreover, Wei
Leong and I are waiting for the interference filter.
Cheers,
(31 May 2003
® . . . . . .Subject: 20030531 Mars in this morning
Dear friends,
The sky continues clear, but it also continues bad seeing and
poor transparency due to the strong easterly air stream is affecting south
Attached is the best one I could captured
from a dozen of avi recorded. The CM is similar to
the one I posted yesterday. The image was stacked with 500 raw, so it appears a
bit noisy.
http://www.ort.cuhk.edu.hk/ericng/mars_200305312123_eric.jpg
The dust streak is barely visible and seems moving towards
Solis Lacus region. May someone kindly comment on it. Polar hood is visible and
the limb brightening is not as obvious as previous two days.
Clear, steady and high
transparent skies.
(1June 2003
email))
® . . . . . .Subject: 20030601 Mars in this morning
Dear friends,
The sky condition is similar as last night. I tried using
F42 by increasing the back focus of CCD sensor to the barlow lens. I found there is a yellowish streak near
the region of Aurorae Sinus ... I am not sure whether it is the same dust
streak as the one taken by Maurice and me respectively on 29 June. It is
visible on both the red and green. The limb haze and NPC hood is beautifully
shown on B frame. I have compared the recent images and it do
shows the changes of the limb brightening and the polar hood.
http://www.ort.cuhk.edu.hk/ericng/mars_200306012111_eric.jpg
Hope the seeing and transparency can be improved as I hate
such noisy image. :-(
Regards,
(
® . . . . . .Subject: Satisfactory 20030602 Mars in this
morning
Dear friends,
This morning the seeing and transparency were better. I took
some Mars shots and attached is the one I am quite satisfied with it. The image
was taken at F34 and I resized to 160% after processed. The transparency is
still not very pleasing and through the eyepiece, mars appear quite orange
tone. Some cloud features can be found on "B" frame.
The most interesting is the dark region of SPC. You can see
some detail on it and it seems the surface of Mars inside ice cap is visible. May some other kindly comment on the image.
http://www.ort.cuhk.edu.hk/ericng/mars_200306022055_eric.jpg
Regards,
(
® . . . . . .Subject: Reprocessed 20030602 Mars
Dear friends,
I have reprocessed the 20030602 Mars that I posted earlier.
This time I separately process the RGB components. For the B frame, seems the
wavelet filter reduced the brightness very much for previously version. So this
time I use weaker processing for it.
http://www.ort.cuhk.edu.hk/ericng/mars_200306022055_eric_final.jpg
May I seek your comment on this version as I would like to
refine my processing.
Kind Regards,
(
® . . . . . .Subject: 20030604 Mars
Dear friends,
Seeing and transparency are similar as 2nd June in this
morning. I was able to capture some shots. This one was captured at 21:24UT.
This time I increased the Focal Ratio to F42 (approx). As the transparency is
not pleasing, the image appear a bit noisy (80% gain) after processed. Seems
high focal ratio is better be used under high transparency.
The AM limb brightening is well shown on the image and the
NPC hood is smaller. The SPC is very bright and some region is saturated. No
visible dust activities detected
http://www.ort.cuhk.edu.hk/ericng/mars_200306042124_eric.jpg
It will cloudy and raining in coming days until early next
week in
Cheers,
(
® . . . . . .Subject: Another 20030604 Mars
Dear friends,
Here is another 20030604 Mars. Seeing was not as good as the
one sent earlierThe Syrtis major with haze can be
seen at the p. limb. The GAMMA setting for this image is too high so limb
darkening looks too contrasty. Moreover, transparency
during this shot is not good so I used F34.
http://www.ort.cuhk.edu.hk/ericng/mars_200306042016_eric.jpg
Kind Regards,
(
®. . . . . .Subject:
200300617 mars (good seeing)
Dear friends,
Finally the sky was clear last night until this morning. Not
only the seeing was good, the transparency improved a lot too!!! (compare with the one taken on 4 June). This time I used the Baader UV/IR Blocker instead of TrueTechnology
one. The transmission of the visible wavelength is 98%.
http://www.ort.cuhk.edu.hk/ericng/mars_200306172044_eric.jpg
As I was quite rush to back to
office this morning. After selected and stacked the avi, I was lucky to see Damian is online in my ICQ list. He
is so kind to process the composite raw I sent to him. Such joint effort is
really great, both of us appreciate it very much.
As Wei Leong
pointed out toucam + IR blocker, the results is no obvious difference with the restricted bandpass 400-500nm and 600-700nm by using magenta filter.
Therefore, I preliminary stacked the one without magenta filter in this
morning. I shall process another one with magenta filter with RR(G)B or R(G)B and see the results.
It seems there are some yellowish (dust?) clouds above the
Please kindly comment on it.
Clear Skies,
(
® . . . . . .Date: Thu,
From: Eric Ng
<ericng@cuhk.edu.hk>
To: "M.
Minami" <vzv03210@nifty.com>
Cc: Damian Peach
<dpeach_78@yahoo.co.uk>,
Tan Wei Leong <weileong@singnet.com.sg>
Subject:
Test result of Magenta filter for Mars imaging
Dear Minami,
During the imaging section on 17 June, I have taken some
shots with Magenta filtered for cutting out 500-600nm bandpass
according to the method suggested by Weileong and
Damian. The image contains no 500-600nm signal. I have processed one of the
shot taken with it. I am attaching it for your reference. This one the (G) is
the average R and B. From the raw image, you can notice the serious atmospheric
dispersion of R and B. Here is the link contains the idea and concept of
Magenta filtering for Mars imaging with ToUcam by Weileong
and Damian peach.
http://www.sg-planets.org/toucam_mars.html
As the ToUcam Pro CCD sensor too mix in RGB channels which
is your major concerns for Mars. The attached image is for your comment and
advice. I am not sure whether the result is satisfied or convincing. Your invaluable experience surely vital to our trial in this
experiment.
I will keep reporting the test results in coming imaging
section. Many Thanks. BTW, many
Cheers and Kind Regards,
® . . . . . .Subject: 20030618 Mars
Dear Friends,
Attached image was captured at 20:51UT. The sky was no cloud
but lower transparency compared to 17 June. Seeing was fair. UV/IR cut added, RRGB
combined.
http://www.ort.cuhk.edu.hk/ericng/mars_200306182051_eric.jpg
Regards,
(
® . . . . . .Subject: 20030619 Mars
Dear friends,
Last night sometimes cloudy and
clear near sunrise. The transparency was bad (Yellow moon
with the halo). Luckily still be able to capture the relative steady moment.
The captured time of this shot is same as the 20030618 I posted. I am waiting
the region where has the orographic cloud a few days
later.
http://www.ort.cuhk.edu.hk/ericng/mars_200306192051_eric.jpg
Regards,
(
Dear friends,
Attached is the 20030617 Mars image stacked with Szeto's and mine. What a coincidence that we captured Mars
at same time in
Quite interesting.
Please feel free to comment.
Clear Skies,
(
® . . . . . .Subject: 20030622 Mars in this morning
Dear all,
Attached please find the Mars
images taken in this morning. Seeing was very fluctuate and clouds were keep rolling across the sky. The orographic clouds near the AM limb.
http://www.ort.cuhk.edu.hk/ericng/Mars_200306222044_eric.jpg
http://www.ort.cuhk.edu.hk/ericng/Mars_200306221912_eric.jpg
Regards,
(
® . . . . . .Subject: 20030623 Mars
Dear friends,
Attached was the Mars taken on 20030623 at 21:00UT. Some problem for the mounting so that only captured a very few
shots. :-( ...
http://www.ort.cuhk.edu.hk/ericng/Mars_200306232100_eric.jpg
Regards,
(
Eric NG (
