Adventures With High Resolution Webcam Lunar Mosaics

I

terminator

Lunar Terminator on November 5, 6, and 7, 2004

Click here for full size image (2172 X 3132 pixel 613 Kb)


These initial mosaics of the terminator were limited to just a few frames by the small 4
Gigabyte hard drive space in my wife's old Dell laptop. It was only laptop I had access
to when starting to use a webcam. It was a good machine in its day, but now it just
serves as an email and web surfing computer. However, it does illustrate the need
for large hard drive space when webcam imaging.

Webcam imaging of solar syatem objects, by the nature of its combining hundreds of
individual frames into a single image, and the amazing image processing power of
programs like RegiStax, allow images of the Moon and planets acheive much higher
resolution over a given area of the target than that acheived with film or digital still
cameras. But if the seeing is really bad, horrible actually as in the November 5th mosaic,
resolution will still suffer.

The technique for making simple mosaics of the lunar terminator is to simply advance the
field of view about 75% up or down the edge of the Moon. It is best to orient the camera
with the north-south directions on the Moon. If the camera orientation is not square with
the lunar cardinal dirrections, the mosaic takes on a sawtooth pattern as displayed in
most of these terminator mosaics.

terminator

Lunar Terminator on December 18, 20, and 21 2004

Click here for full size image (2888 X 3276 pixel 642 Kb)


After more than a month of rotten weather, I secured some
more mosaics of the terminator just before Christmas.
By now I was unsatisfied being limited to just the terminator
and wanted to exapand the mosaics to include the entire
Moon. Fortunately, about this time I inherited (rescued
from a trash can) another laptop that had suffered hard drive
failure. Installing a new 20 Gigabyte hard drive and reloading
Windows brought the machine back to life and gave me a dedicated
webcam computer with sufficient hard drive capacity to
image the entire full Moon with up to 50 individual video
sequences.

Lunar Webcam Mosaics at 5000 mm Focal Length

These mosaics were taken with an Atik 2hs webcam and TeleVue 2.5X PowerMate through a classic orange-tube Celestron-8 telescope.
The resulting focal length was 5000 mm and the camera utilizes 7.4-micron pixels.
Image stacking was done with a beta version of RegiStax 3D and mosaic assembly was done in Photoshop 7.

Moon July 17, 2006

5802 X 3163 pixel 1.08 Mb .jpg


The 3rd Quarter lunar terminator
on the morning of July 17, 2006.
The seeing varried from good to very good.
Moon Aug 1, 2006

5272 X 2480 pixel 838 K .jpg


The 1st Quarter lunar terminator
on the evening of August 1, 2007.
The seeing was very poor this evening, but the resolution still
approximated that of the Consolidated Lunar Atlas.
pattern

Mosaic Segment Pattern

This partial image of the full Moon mosaic at the bottom of this page
shows the mosaic pattern used to image the entire Moon. Initially,
the camera's wide axis is aligned with the northern edge of the Moon
by slewing the telescope back and forth in right ascention wile adjusting
the camera mounting angle until the northern edge of the Moon travels
parallel with the edge of the camera field of view. Once the camera is
aligned, strips of overlapping images are made by advancing the
camera about 75% of the field of view until one strip of images is complete.
The the field of view is slewed downward about 75% and the next strip
of images is taken. With a 2000 mm focal length, the polar regions
usually require four overlapping images wheil the equatorial regions
use up to six images.

The upward creep of sucessive images as the mosaic segments move
from west to east is a bit of mystery to me since I try to track the Moon
as well as possible. It appears to be more movement than can be
accounted for by the orbital motion of the Moon. However, each strip
of images creeps up at the same rate, so they all overlap anyway.

crescent

Waxing Crescent Moon

Click here for larger image
The image shown here is 1/4 scale the original image


The images shown in this sequence of mosaics is displayed in order
of increasing lunar phase. Therefore, this first image is not really the
first taken. This thin crescent was imaged on February 13, 2005 and is
a mosaic of 22 separate video sequences.

crescent

Waxing Crescent Moon

Click here for larger image
The image shown here is 1/4 scale the original image


After waiting for months after getting my webcam for good weather, I was
finally rewarded with the best resolution image of the full lunar
disk I have ever taken until now through my own telescope. This image is
a mosaic of 20 separate video sequences taken on January 15, 2005.

crescent

First Quarter Moon

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The image shown here is 1/4 scale the original image


After waiting another month for good weather, I was able to
image the first quarter moon on March 17, 2005. 25 separate
video sequences were were processed for this image.

LOOK!


This image may be purchased as a
full resolution 8 x 12-inch 300 DPI print on
heavy premium glossy photopaper.
Click here for ordering information.


waxing gibbous moon

Waxing Gibbous Moon

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The image shown here is 1/4 scale the original image


This is my first attempt at a full Moon mosaic. It is a
combination of 42 separate images taken over about a
two hour span. On this mosaic I discovered a possible
problem with using the basic camera operating program
the comes with the ToUcam. The program requires that
each successive video sequence be named in advance
or the next video sequence will overwrite the previous
one. Out of 42 repetitive videos, one mistake is likely
to happen and it did with this image. I forgot to designate
the file name of a video about halfway through the series
and thus lost a segment along the eastern edge of the
equator. Essentially, there was a hole in my Moon.

Fortunately, Jan Timmermans had imaged the Moon using
a similar camera and focal length about 24 hours after
I made my mistake. He was kind enough to allow me to
"borrow" a chunk of his Moon to patch the hole in mine.
The libration angle was different even after only one day,
but after a little Photoshop work, only experienced lunar
observers can spot the slightly out-of-kilter area on the
eastern equator. Thank you Jan for saving my mosaic!

Notice the Maruis Hills visible along the terminator to the
west of the bright crater Kepler.

full moon

Full Moon

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The image shown here is 1/4 scale the original image


This image is of the January, 2005 full Moon. It was
assembled from 48 individual segments taken during
two hours of imaging. Two things are noticable on the
full-sized version. First, you can see amazing detail
in the southern regions because libration and the tilt of
the Moon's orbit allowed us to see "under" the Moon.
Numerous mountain peaks stand in stark detail. Second,
a close look at the Oceanus Procellarum area reveals the
effect of the wildly variable seeing in my area. Most of the
Moon is sharp, but for a while the seeing degenerated into
a massive blur. Fortunately, this happened while I was
imaging the more bland area of the globe so it is not as noticable.

3rd quarter moon

3rd Quarter Moon

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The image shown here is 1/4 scale the original image


This image is of the August 26, 2005 3rd quarter Moon. This
image is slightly smaller than the previous mosaics
because I switched to an Atik IIhs camera. This camera
has the same number of pixels in a 640X480 array like
the ToUcam 840 used ealier, but the pixel size is 7.4
microns instead of 5.6 microns. The camera thus has
slightly less resolution over a given area of the Moon.
But the bigger pixels are more sensitive and the camera
produces excellent images.
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LOOK!


This image may be purchased as a
full resolution 8 x 12-inch 300 DPI print on
heavy premium glossy photopaper.
Click here for ordering information.

3rd quarter crescent

Wanning 3rd Quarter Crescent Moon

Click here for a larger image
The image shown here is 1/4 scale the original image


This image is the September 28, 2005 3rd quarter crescent
Moon. This is close to as low as I can see the Moon above
the eastern horizon because of tall trees.

3r quareter crescent

Wanning 3rd Quarter Crescent Moon

Click here for a larger image
The image shown here is 1/4 scale the original image


This image is the September 29, 2005 crescent Moon.
I had to wait for the Moon to rise above the trees so
twilight was beginning to be a factor as well as poor seeing
which degraded the image compared to the previos morning.

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