Tampering?

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rderosa</i>
<br />after looking at a couple hundred images this weekend, I have absolutely no faith whatsoever in the consistency of a Non-Map Projected image, relative to a Map Projected image.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Map projecting involves more than re-orientation. Could you provide one example that seems "off"? I'll see if I agree. I've sometimes suspected an orientation error, but never followed up to see if my suspicion could be borne out. But the ancilliary data should help us resolve all questions except near the polar regions, where "north" starts to lose its meaning. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
<br /> Could you provide one example that seems "off"? <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Ok, here's one that we thought was right, in the beginning. The mapped verion is mirrored and rotated relative to the non-mapped one:

Non Mapped SP243004:

www.msss.com/moc_gallery/ab1_m04/nonmaps/SP243004.gif

Mapped SP242004:

www.msss.com/moc_gallery/ab1_m04/jpegmaps/SP243004.jpg


Here's one that doesn't differ that way. One is just rotated relative to the other, not mirrored.

Non Mapped M0203974:

www.msss.com/moc_gallery/ab1_m04/nonmaps/M0203974.gif

Mapped M0203974:

www.msss.com/moc_gallery/ab1_m04/jpegmaps/M0203974.jpg

Here's the site:

www.msss.com/moc_gallery/ab1_m04/images/M0203974.html


rd

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rderosa</i>
<br />Ok, here's one that we thought was right, in the beginning. The mapped verion is mirrored and rotated relative to the non-mapped one<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">True, but both versions (mapped and non-mapped) are "processed". Note that the definition of "North Azimuth" applies only to the raw, unprocessed image, which is not shown for the SP243004 image.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Here's one that doesn't differ that way. One is just rotated relative to the other, not mirrored.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">So for M0203974, everything is normal and the definitions apply just as one would expect. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
<br />True, but both versions (mapped and non-mapped) are "processed". Note that the definition of "North Azimuth" applies only to the raw, unprocessed image, which is not shown for the SP243004 image.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Tom, have you been off studying Fisbin?

Both sets say the same thing. For both sets, they're both "processed", but one set is mirrored and the other one isn't.

In each case one image says:

<u>View full-size image, processed, in sinusoidal projection </u>

And the other says:

<u>View full-size image, processed but NOT map-projected</u>

But yet, in the case of SP24 they're mirrored, and in the case of M020 they are not mirrored.

rd

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rderosa</i>
<br />Both sets say the same thing. For both sets, they're both "processed", but one set is mirrored and the other one isn't.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Right. "Processed" usually means "flat-fielded" or corrected for "striping" caused by each CCD channel having a different sensitivity. Orientation can be anything unless it says "map projected", which is always non-mirrored with north up; or "raw/unprocessed", which must agree with the derived spacecraft ancilliary data.

I don't know exactly why some of the processed, non-map-projected images were mirrored, but suspect it is simply a step in the handling for some images on their way to being flattened, unstretched, and map-projected. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
<br />I don't know exactly why some of the processed, non-map-projected images were mirrored, but suspect it is simply a step in the handling for some images on their way to being flattened, unstretched, and map-projected.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Fair enough. But it does present a problem for the casual user of the MSSS website. We're forced to make a decision as to which conclusion we come to. Namely, how do we diffentiate between a mirrored-non-map-projected image, and a non-mirrored-non-map-projected image?

What criteria do we use to determine which one is which? I personally found it impossible to tell <i><b>what</b></i> to trust.

rd