Hi all,
Attached is my latest images of the storms on Saturn, currently their are clearly two storms. On the 19/06/2008 I produced 8 RGB images of the storm structures over about an hour.
The attached images is heavily processed to enhance the contrast between the storms and atmosphere.
Hi Mike,
I use my observatory mounted scope, a 16" F4.5 newt on a very heavy German Eq mount designed and built by me. The scope is highly modified. The primary mirror cell and secondary mirror mount are designed and built by me. The primary mirror cell is 27 point made from 25mm by 25mm squ tubing with 3mm wall, all fully welded. The cell is triangulated, very rigid allowing excellent air flow to the back of the primary. I have a cooling fan forcing air over the back of the mirror. This air flow makes a considerable difference to the quality of the live feed from the CCD at high magnifications.
The focuser is a JMI motofocus and the CCD is a DMK 21AU04.AS. I use an Orion 5 position manual filter wheel loaded with Astronomic LRGB filters.
The scope drive is dual axis by Peter Mellander from Anssen Technologies with remote drive corrector.
I am now up to about 150 avi's of the storms and really by trial and error have arrived at settings that work best on my system for the results that I an trying to deliver for Georg.
I use the DMK provided IC capture. If I am using monochrome I go with Brightness at 50 Gain at 600 Gama at 160, Exposure of 1/30, Frame rate 30/sec which gives me a Histogram at 200.
When I RGB for the R and G avi's I have the Brightness at 50, Gain at 760, Gama at 180, Exposure 1/23, Frame rate 30/sec which gives a Histogram of 150. For the B channel I use the same settings but change the exposure to 1/15 to bring the Histogram back up to a similar position to what it was for the R & G channels.
If I am imaging in monochrome I capture 1000 to 1200 frames if I am capturing RGB's I capture about 600 frames for each channel.
I initially stack and process in RegiStax 4 and generally stack half of the frames from each channel that normally results in about 95% quality of the tagged frame.
For the purpose of revealing any storm structure I use the wavelet processing in RegiStax much more heavily than I would to make a nice picture, typically slider1 set to 40, Slider 2 to 20, slider 3 to 10 and so on.
I then load my images into Astra Image 3.0 Pro. I have found that for grey scale images the maximum entropy deconvolution filter works well. It does nothing for the esthetic's of the image but if there is very small structure it does reveal it.
For my RGB avi's I use the LR deconvolution filter generally 4 iterations at a level of 1 for each individual channel before they are merged.
I love how accurately Astra Image 3.0 Pro allows me to merge the RGB channels.
This RGB imaging is all new to me, all of my deep sky imaging over the years has been on 35mm film hand guided. Over the last few years I have done a fair bit of imaging with a ToUcam. I would love to become more competent with my RGB imaging, the more of it I do the better the results I am getting, still not a patch on some of your work I have seen since being on Iceinspace. I am very isolated out here and there is no one else in my region doing this, it would be great to have someone else to bounce ideas off.
Hi Renormalised,
Mate,........ compared to the size and brightness of some of the storms I have imaged since Feb these are truly like beacons.
I have spent so many hours concentrating on this type of image that I can virtually sense if something is there, if it is worth going further with the processing.
Hi Renormaised,
Georg is an authority on planetary lightning, infact his PHD was based on it. He has very graciously sent me three of his papers on it. Specifically on Saturn's SED's "Saturn Electrostatic Discharge".
Two of these papers were published last year in Icarus and the third has not yet been published and he has asked me not to circulate it.
The atmosphere of Saturn has three well defined cloud layers. An upper layer of ammonia ice crystals, a middle layer of ammonia hydrosulphide crystals and a lower layer of water ice crystals. These layers extend to a depth of about 300 km.
The SED's are thought to originate deep within the atmosphere at about 200 to 300 km depth. They are thought to be directly due to rapid vertical movement of water clouds at up to 150 m/s, this column breaks through the upper ammonia crystal clouds and then mushrooms over the top resulting in the bright white spots imaged by amateurs from Earth.
Some times these spots have been so close together that the only way I have been able to image them is monochrome, there has simply not been enough time to RGB them they would have merged into one. Each night I do this I start with a couple of monochrome images to see how many storms are visible and if they are separated enough for me to RGB them.
I really enjoy doing this and although I am rapidly running out of time before I lose Saturn over my local horizon. When that happens I will look forward to reaquisition in the morning sky.
Hi AlexN,
Yes it is a very substantial mount designed and built by me. It incorporates very fine adjustment in azimuth and altitude and is very accurately polar aligned. The polar axis spins in thrust bearings at the load bearing end with double row ball bearings at the rear end. The shafts are solid 2.5" stainless steel. The mount is so good that when I manually advance the filter wheel I can start the next exposure as quickly as I can get back to the keyboard of my computer, as soon as I remove my hand from the filter wheel the image is rock steady.
Hi Renormaised,
Georg is an authority on planetary lightning, infact his PHD was based on it. He has very graciously sent me three of his papers on it. Specifically on Saturn's SED's "Saturn Electrostatic Discharge".
Two of these papers were published last year in Icarus and the third has not yet been published and he has asked me not to circulate it.
The atmosphere of Saturn has three well defined cloud layers. An upper layer of ammonia ice crystals, a middle layer of ammonia hydrosulphide crystals and a lower layer of water ice crystals. These layers extend to a depth of about 300 km.
The SED's are thought to originate deep within the atmosphere at about 200 to 300 km depth. They are thought to be directly due to rapid vertical movement of water clouds at up to 150 m/s, this column breaks through the upper ammonia crystal clouds and then mushrooms over the top resulting in the bright white spots imaged by amateurs from Earth.
Some times these spots have been so close together that the only way I have been able to image them is monochrome, there has simply not been enough time to RGB them they would have merged into one. Each night I do this I start with a couple of monochrome images to see how many storms are visible and if they are separated enough for me to RGB them.
I really enjoy doing this and although I am rapidly running out of time before I lose Saturn over my local horizon. When that happens I will look forward to reaquisition in the morning sky.
Regards
Trevor
Thought so....very similar cloud formations (and compositions) on Jupiter as well. Yeah, water ice would also be another good candidate. The mechanisms of formation of those storms sounds quite similar to the way thunderstorms form on Earth, except that the heat source on Saturn would be for a majority of cases internal, and not from sunlight. But that would depend on how well the clouds there trapped what little heat they got from the Sun. Seems like the formation of lightning there is pretty similar to terrestrial lightning...separation of charge. Only a lot more energetic!!!!.
Hi AlexN,
Yes it is a very substantial mount designed and built by me. It incorporates very fine adjustment in azimuth and altitude and is very accurately polar aligned. The polar axis spins in thrust bearings at the load bearing end with double row ball bearings at the rear end. The shafts are solid 2.5" stainless steel. The mount is so good that when I manually advance the filter wheel I can start the next exposure as quickly as I can get back to the keyboard of my computer, as soon as I remove my hand from the filter wheel the image is rock steady.
Regards
Trevor
Trevor, ever thought of manufacturing your mounts commercially??. You may make some money out of it!!!
Thought so....very similar cloud formations (and compositions) on Jupiter as well. Yeah, water ice would also be another good candidate. The mechanisms of formation of those storms sounds quite similar to the way thunderstorms form on Earth, except that the heat source on Saturn would be for a majority of cases internal, and not from sunlight. But that would depend on how well the clouds there trapped what little heat they got from the Sun. Seems like the formation of lightning there is pretty similar to terrestrial lightning...separation of charge. Only a lot more energetic!!!!.
You have it in a nutshell, very similar to the way thunderstorms form on Earth. The heat source is most definitely internal and using RPWS data combined with amateur data from Earth Georg hopes to gain a greater understanding of the dynamics of the processes at work driving these electrostatic discharges.
Critical to this is the supply of images by amateurs.
