Titan flyby next week!
WOW !!!maxim wrote:The recently announced decision to implement and test some AI features like strategy planning and self repair for future probes is certainly a good step. And as soon as there are serious plans for granting every planet and every moon it's own durable satellite probe, the first real golden age of planetary exploration will definitely rise.
http://www.spiegel.de/wissenschaft/weltraum/0,1518,326001,00.html
An article about the ESA test satellite PROBA (in german unfortunately). A cheap, small and widely autonomically operating satellite for testing new space technologies. Just as easy to operate as using celestia. If it is provided with a longitude, latitude and altitude parameter, it just goes there and takes a photo. It did so for over 10,000 times in the last three years. Everything else, like flight positioning control, target detection, and image aquisition is done by the probe itself.
Hopefully they spread some dozens of these all over the solarsystem as soon as possible
maxim
http://photojournal.jpl.nasa.gov/catalog/PIA06992
Original Caption Released with Image:
Saturn's moon Titan shows a sharp contrast between its smooth and rough edges in a new false-color radar image.
To provide a better perspective of the surface features, the color image is shown alongside a black and white image that was previously released. To read the full caption for the black and white image click here PIA06988.
In the new color image, brighter areas may correspond to rougher terrains, slopes facing the radar, or different materials. The pink colors enhance smaller details on the surface, while the green color represents smoother areas. Winding linear features that cut across dark areas may be ridges or channels, although their nature is not yet understood. A large dark circular feature is seen at the western (top left) end of the image, but very few features on Titan resembling fresh impact craters are seen.
The area shown is in the northern hemisphere of Titan and is about 150 kilometers (93 miles) wide by 300 kilometers (186 miles) long. The image is a part of a larger strip created from data taken on Oct. 26, 2004, when the Cassini spacecraft flew approximately 1,200 kilometers (745 miles) above Titan's surface.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument team is based at JPL.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov.
bye
Original Caption Released with Image:
Saturn's moon Titan shows a sharp contrast between its smooth and rough edges in a new false-color radar image.
To provide a better perspective of the surface features, the color image is shown alongside a black and white image that was previously released. To read the full caption for the black and white image click here PIA06988.
In the new color image, brighter areas may correspond to rougher terrains, slopes facing the radar, or different materials. The pink colors enhance smaller details on the surface, while the green color represents smoother areas. Winding linear features that cut across dark areas may be ridges or channels, although their nature is not yet understood. A large dark circular feature is seen at the western (top left) end of the image, but very few features on Titan resembling fresh impact craters are seen.
The area shown is in the northern hemisphere of Titan and is about 150 kilometers (93 miles) wide by 300 kilometers (186 miles) long. The image is a part of a larger strip created from data taken on Oct. 26, 2004, when the Cassini spacecraft flew approximately 1,200 kilometers (745 miles) above Titan's surface.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument team is based at JPL.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov.
byewindows 10 directX 12 version
celestia 1.7.0 64 bits
with a general handicap of 80% and it makes much d' efforts for the community and s' expimer, thank you d' to be understanding.
celestia 1.7.0 64 bits
with a general handicap of 80% and it makes much d' efforts for the community and s' expimer, thank you d' to be understanding.
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Spaceman Spiff
- Posts: 420
- Joined: 21.02.2002
- With us: 22 years 9 months
- Location: Darmstadt, Germany.
To interpret SAR imagery better (as I had to do for a prior job), turn the NASA images upside-down.
Currently, they're presented with radar 'illumination' from the bottom (sub-satellite track). SAR images image in azimuth and slant range, not azimuth and elevation like a photograph. They're notoriously difficult to interpret due to artefacts. One is that mountains can 'poke back' into the slant range which gives the effect of them being bent over back down towards the source of radar illumination. The effect is called slant range 'layover'.
I find it better to turn the pictures upside down. That way, you get the illusion that illumination comes from across the far side of the image, and you see the shadowed side of mountains facing you. It creates a better impression of relief.
I've found my first mountain. It's in the third SAR image that was released (the 'ooze' picture). It's in the top-left, NASA way), and you can recognise it as a bright, thin U shape.
There are also two impact craters (maybe not?) towards the illumination side, the larger one half off the image. By the way, the 'ooze' image is contiguous with the 'cat' image, so join them up (but you'll have to resize one, as they were put out at different 'magnifications').
The one that's multi-coloured is great. It's full of river valleys, and there are three canyons in the dark patch. I think that's a plateau or dome. The bright patch with the two v-shapes on the other end is interesting. Proposed as a mountain range, it reminds me more of the Ijselmeer ERS SAR image. The streaks look like SAR images of seas, either calm/rough sea areas due to wind-wave interaction, or salinity, or even oil-slicks (liquid methane in liquid ethane?), and the V shapes are like estuaries. Above it (away from sub-satellite track), is a river delta.
But who knows...
Have fun,
Spiff.
Currently, they're presented with radar 'illumination' from the bottom (sub-satellite track). SAR images image in azimuth and slant range, not azimuth and elevation like a photograph. They're notoriously difficult to interpret due to artefacts. One is that mountains can 'poke back' into the slant range which gives the effect of them being bent over back down towards the source of radar illumination. The effect is called slant range 'layover'.
I find it better to turn the pictures upside down. That way, you get the illusion that illumination comes from across the far side of the image, and you see the shadowed side of mountains facing you. It creates a better impression of relief.
I've found my first mountain. It's in the third SAR image that was released (the 'ooze' picture). It's in the top-left, NASA way), and you can recognise it as a bright, thin U shape.
There are also two impact craters (maybe not?) towards the illumination side, the larger one half off the image. By the way, the 'ooze' image is contiguous with the 'cat' image, so join them up (but you'll have to resize one, as they were put out at different 'magnifications').
The one that's multi-coloured is great. It's full of river valleys, and there are three canyons in the dark patch. I think that's a plateau or dome. The bright patch with the two v-shapes on the other end is interesting. Proposed as a mountain range, it reminds me more of the Ijselmeer ERS SAR image. The streaks look like SAR images of seas, either calm/rough sea areas due to wind-wave interaction, or salinity, or even oil-slicks (liquid methane in liquid ethane?), and the V shapes are like estuaries. Above it (away from sub-satellite track), is a river delta.
But who knows...
Have fun,
Spiff.
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Topic authorEvil Dr Ganymede
- Posts: 1386
- Joined: 06.06.2003
- With us: 21 years 5 months
The one that's multi-coloured is great. It's full of river valleys, and there are three canyons in the dark patch. I think that's a plateau or dome. The bright patch with the two v-shapes on the other end is interesting. Proposed as a mountain range, it reminds me more of the Ijselmeer ERS SAR image. The streaks look like SAR images of seas, either calm/rough sea areas due to wind-wave interaction, or salinity, or even oil-slicks (liquid methane in liquid ethane?), and the V shapes are like estuaries. Above it (away from sub-satellite track), is a river delta.
That's flat out a matter of opinion though.
Fact is, the images are still very ambiguous (what you call river valleys could be wrinkle ridges, or landslides), so much so that scientists on the imaging teams still aren't able to say for sure whether there's liquid on the surface or not. I sure as heck can't tell...
(and to me, the images look very reminiscent of what we saw of Venus).
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Spaceman Spiff
- Posts: 420
- Joined: 21.02.2002
- With us: 22 years 9 months
- Location: Darmstadt, Germany.
Evil Dr Ganymede wrote:That's flat out a matter of opinion though.
Yes, but I'm just having a little fun being bold in my speculation. It's a popular sport on this forum, I note, and also I think it ties in with your caution about interpreting such unfamiliar imagery (I was letting the 'reference' I used (Earth's rivers) colour my opinions, if you like). I did add "But, who knows..."
.
However, I'd not go along with those several sinuous features being wrinkle ridges or landslides. The sinuous features appear to be less or equally wide than the SAR resolution (500m I read), appear equally strong at many bearings the features follow, and have a 'wiggliness' more like rivers in plains than wrinkle ridges (tend to be rather straighter over distance), or landslides (tend to have lobate edges, and shouldn't be bright on edges facing sway from the source). I could go along with edges of lava flows, but then I'm still wondering how the far edges are bright.
Yes, I can see why you see a similarity to Magellan SAR imagery of Venus, but have you also seen SAR imagery of Earth, too? Otherwise, as the only other radar imaged planet, is Venus serving as your 'reference'?
Anyway, did you find any use on the 'upside-down' tip I mentioned? One worry I have is that I've now realised the 'multi-colour' picture may already have been inverted, and I changed it unnecessarily. Correcting, I find the two 'estuaries' now become the illumination-facing sides of two big mountains, and the three canyons become straggling 'lava' flows. It's a problem that we are able to get from NASA these pictures unannotated with illumination direction, incidence angle, lat-long marking, etc. Ah well...
Another difficulty is the radar used Ku-band, which is terrible for landscape imaging in SAR. I hope they can switch to S-band soon.
Did you find my 'mountain' and 'impact craters'?
I still think Titan's largely become a 'desert' world, with little open liquid or precipitation.
Spiff.