http://www.unmannedspaceflight.com/doug_images/635A_L7.jpg (1.2mb)

Prospecting for a bit of a view into the Eastern Basin ( which we've not seen very well yet )

I'm not 100% sure - but are we seing the near rim of Thyra, the far rim of Thyra, and then the rim of Gusev on the Horizon in order?

Doug

No, they are stretching them for the Cassini website - and infact they've changed the algo. they're using to do it because it was ruining all images of a small moon on a dark background.

Look at images with a full field of view of moon, compared to images with a small moon - the moon is 10, 20, 50 x brighter when small because of the stretching.

Doug

Yeah - we've needed something like this ever since napacomfort or some URL like that vanished

Doug

As I understand it - these types of instruments can only detect a transition between layers.

i.e. you could have a iceberg sat on the surface, but it would only tell you about the change between the iceberb and the surface under it - not the actual material itself.

Doug

Yes - and MER data gets released more frequently and with less of a delay than any other mission I know of. Up to sol 360 is available now, and up to Sol 450 will be available in two weeks time. If you tried to do Tau measurements from the JPG's - you'd end up with exactly the same value for both rovers for 600 sols

Doug

You CAN go and get properly calibrated data...

BUT

The JPG's that get put in the Cassini and MER websites are automatically stretched, and there is no way of getting them back to any form of calibrated data.

As an experiment - take a calibrated MER or Cassini image - then in photoshop, do 'auto levels'. - that's basically what you're getting - and there's no way to reverse or backward engineer the process in any way whatsoever. Dont both trying, it's an impossibility. Sadly there are some people ( none here thank goodness ) who claim to make 'true' colour imagery from the JPG's. They're just kidding themselves.

The reason they do it is because of the huge range of brightness we get from image to image - they do it to be sure that we can actually see something every time - if they didnt, half the images would be too dark to see half probably too bright

Notice that they've not been flatfielded either - if you compare a raw JPG, and then find a calibrated one - it's like two different images. You can fudge it a bit - you can have a play - but you cant - you just cant get to anything like a calibrated image from the JPGs. It cant be done.


Doug

Oh there isnt any, the same as with MER imagery.

Doug

I thought the move from dirty-ice-ball to icy-dirt-ball was already a popular theory before DI

Doug

As far as I can tell it doesnt add any features- I was hoping that at some point, they would integrate MOC, Themis, HRSC and Viking imagery into one interface

Doug

" you are talking about data not received but I think they were actually not executed."

We dont know that. All we know is what was requested, and what was recieved. We dont know that it didnt happen - I'm assuming they didnt execute, or only partially executed, obviously - but we dont actually KNOW that.

Doug

As I read it using the Pancam website....looking back to Sol 608...

608: A driving day was commanded, and at least some of that drive occured (3 of 5 stumble checks)

609: Remote sensing commanded, and executed and downlinked in full
http://qt.exploratorium.edu/mars/opportuni...JLP2537R7M1.JPG

610: Driving sol commanded - no data recieved at all as yet

611: Commanded a single observation
p1950.23 nav_mtes_rvrAz0_ElN45_1bpp_pri57 but not recieved.

612: Driving sol commanded ( same as 610 ) - but again, nothing recieved.

613: Lots of remote sensing commanded but not recieved

614: Some remote sensing commanded

615: Driving day commanded

that is as of sol 613.9

Now - as I see it, they wouldnt have commanded driving and remote obs 2 sols in advance if they didnt think the rover was healthy - BUT - there clearly was a problem on 610. It might be a different link in the chain of course - just new imagery not filtering thru to the DB or the raw image pages, or even a problem with Odyssey perhaps - who knows.

Possible events - 610: Problem with the drive, 611: Rover checkout, MiniTES trouble? 612: Prognosis healthy - command driving, 613: Lots of remote obs with healthy rover 614: Housekeeping to cure 610 problem a little better, and some remote obs, and 615 on the road again.



Doug

Jim said the tracking website was being a little funny a few days ago,

perhaps that is where the problem lies, not on Mars BUt it does look a bit ominous - 611 was a single navcam image to match a Mini TES observation - perhaps that's put a spanner in the works

The reason they're not driving every day right now is two fold

1) Restricted Sols
2) Harsh terrain that requires planning to navigate thru

Imagine if you had dust on your car and did 0.1 mph, and then stopped suddenly Nothing would happen

There are three things you can do to improve power for Opportunity

1) Pray, do a wind-dance or any other luck-bringing activity

2) Find, where possible - sun facing slopes ( which at summer, is flat terrain )

3) Do driving. It's possible that the small shocks of driving over terrain might 'rattle' dust a little - again, unlikely, but it might have a contributing factor.

Doug

Notice they actually caught M42

OK - I admit it, I only know it's M42 because I googled for Orion Nebula

If you do the maths, those are something like 1 minute exposures, so the chances of catching a meteor are fairly small - they're more likely to be cosmic rays, but it's worth looking for eh

Doug

A comic ray hit doesnt tend to fade up and down does it?

http://www.unmannedspaceflight.com/doug_im...irit_meteor.jpg

Doug

No need for an inquisition Mike, and to be fair Nirgal speculation is no more of less so than yours.

I would venture to say that as the administrator of this forum, I can look at the IP addresses of each and every single post ever made here, and could identify if someone were posting under multiple usernames, and after your post I checked with Ustrax's user ID and his IP doesnt appeare for other members.

I think we should leave the explanation to Ustrax himself
"I've been full of work"


Doug

Well - they might be meteor watching, or alternatively, using the known brightness of stars to measure atmospheric opacity at inght.

But, let's face it...they're cool

Doug

Mother Nature is without doubt the greatest artist of all.


Doug

I've tried stretching, and even grabbed the pds file to have a look, but I couldnt pull tracks out of it.

Doug

I cant wait for Minerva to get 'down amoung 'em charlie' on that lump - it's going to be...I hate to use the word...but.....cool

Doug

That's cheating OK - I'll give you that one, there might be solid kick-motors to seperate the solids as well, and solids for the retro-fire just before touchdown a-la Soyuz.

Doug

They're not solid motors - the whole vehicle is liquid fueled...
http://www.astronautix.com/lvs/cz2f.htm

Solid motors would chuck out huge quantities of thick smoke - and if you notice, the CZ-2F has little engine plume once clear of the pad, much like a Proton or Soyuz launch.

The brown is actually a symptom of the fuel, not what I initially thought ( that harks back to me mixing up the reason for a strange noise before Titan 2 launch which WAS a little motor firing up the turbine, and the colour of the smoke chucked out which was due to the type of fuel ) It's all N2O4/UDMH for the CZ-2F - the strapons, the main stage ( which is simply the same motor as the strap ons 4 times over ) and the upper stage.

For instance, compare these two Atlas V launches

http://www-pao.ksc.nasa.gov/kscpao/images/.../05pd1870-m.jpg

http://www.spaceflightnow.com/atlas/av004/...hgallery/16.jpg

The first was purely liquid fueled.

The second has two solid-fuel strap ons.

See the difference in the plume

Doug

http://www.msss.com/moc_gallery/r22_s04/narrowangles.html

Of interest....

Opportunity site
http://www.msss.com/moc_gallery/r22_s04/im...2/R2200640.html (Endurance to Victoria )

Spirit Site
http://www.msss.com/moc_gallery/r22_s04/im...2/S0200972.html (just gets Home Plate)

That brief burst of brown/red exhaust is something that the Titan 2 exhibited as well, i believe it's a small motor used to kick start the compressor turbine.

Doug

Yup - Purgatory 2 is right on the left there, then a rather brave drive between bits of dune to head out onto more outcrop...

The rover drivers are getting very clever

Looking at the increasingly valuable pancam tracking those navcam frames are from...
608 p1655.01 10 0 0 10 0 20 navcam_5x1_az_90_1_bpp

609 was restricted, and 610 was further driving. These reports of 30 - 40+ metre drives are very promising, even with restricted sols, that's a weekly drive distance of 150m or so, not too shoddy.

Doug