New Horizons: Pre-launch, launch and main cruise, Pluto and the Kuiper belt Options

[ugordan]

[FROM A LATER EMAIL:]By the way, for your last question about the distortion correction, it turns out that there may well be an error in the algorithm we used for the TDI (color) channels, so you are not crazy. I'll let you know when we track it down.

Well, that's what a little snooping around will do for you.

I wonder if it's also inevitable for the distortion-corrected frames to look noticeably blurrier than the uncorrected ones (from what few frames I've looked at)?
Resizing or subpixel shifting requires very good algorithms and when I process imagery in Photoshop, I find its resize algorithms (including all bicubic variants) are lacking in that regard, they inevitably blur the image even if all you want to do is accurately align the 3 color channels down to sub-pixel accuracy (say, scaling up 5x, shifting and scaling down). I'm often compelled to live with a slight color fringe in return for having sharper imagery.

Since I've touched the subject, does anyone know of image processing software that implements better resize algorithms (such as lanczos3)?

[volcanopele]

I would be interested in those index files in Excel format. Access is not installed on any machine I use, either at home or work.

[elakdawalla]

Your wish is my command

http://planetary.s3.amazonaws.com/data/met...er_mvic.xls.zip
http://planetary.s3.amazonaws.com/data/met...r_lorri.xls.zip

--Emily

[volcanopele]

Sweet! Thanks!

The LORRI link is broken though. I get an XML Access Denied page.

[djellison]

Whilst discussing MVIC / Ralph - here's a shot of the spare CCD they have at the London Science Museum, and a map from the PDF here : http://www.boulder.swri.edu/pkb/

Up close, these things ( when not filthy dusty ) are very pretty - lovely colours from different angles.

Doug

Attached thumbnail(s)

 

[elakdawalla]

The LORRI link is broken though. I get an XML Access Denied page.

Oops. Try it again now.

[volcanopele]

Works now thanks!

[john_s]

Your wish is my command

Thanks Bjorn and Emily! I think even those of us on the New Horizons team might find those spreadsheets handy.

John.

[Bjorn Jonsson]

I guess I'm lazy asking here instead of reading the documentation but I really want to start digesting the NH images by converting them to PNGs ASAP. I now have a working FITS to PNG converter (actually it's a part of IMG2PNG); only a few minor 'tweaks' are left.

So here I go:

(1) Does anyone know what those three images in each of the LORRI files are? The first two look similar but most (all?) of the pixels in the third one are of uniform brightness.

(2) The MVIC files contain four images. I haven't looked closely at them yet but the fourth one seems very uniform (the resulting PNGs are small, meaning it compresses well). Is it correct that images 3 and 4 contain information on errors and data quality as was stated in an earlier messages in this thread? Image 3 looks like a 'real' image so I'm a bit surprised if this is the case.

[elakdawalla]

Arg! Internal server errror lost my message the first time around! Here goes again...

You want the ICD for this information. Section 9 for LORRI, 10 for MVIC. You should probably read these, they're informative on what exactly each extension is, and also on what's corrected and what's not in the calibration (for instance, readout smear correction on LORRI doesn't work so well when there are saturated pixels). Copying from each section:

LORRI:
9.2.1 Data Format
The raw image data is organized in a FITS file. The primary header and data unit (HDU) is used to store the reconstructed image from telemetry. Additional data are stored in the extensions of the file. The two tables below contain a description of the layout for the extensions for raw data.
As described previously, LORRI operates in two binning modes: 1x1 and 4x4. For the 1x1 binning mode, the raw image dimensions are 1028x1024 where columns 0 through 1023 are the optically active region of the CCD and the remaining columns (1024-1027) are from optically inactive region (dark columns) of the CCD and represent a temperature-specific measurement of the bias value. For the 4x4 binning mode, the raw image dimensions ar 257 x 256 where columns 0 through 255 are optically active and column 256 for the dark column.
FITS File Storage Location Description
Primary HDU Reconstructed image from telemetry
First Extension histogram from image descriptor packet (APID 0x611)
Second Extension Instrument housekeeping from first 34 pixels
Third Extension Matching image descriptor




MVIC:
Table 10.2 Observation Modes and their filename prefixes and data dimensions
Detector Prefix for FITS file Dimensions of data in FITS file
Pan Frame Mpf 3 (5024 x 128x Ni)
Pan 1 mp1 2 (5024 x Nr)
Pan 2 mp2 2 (5024 x Nr)
Red mc0 2 (5024 x Nr)
Blue mc1 2 (5024 x Nr)
NIR mc2 2 (5024 x Nr)
CH4 mc3 2 (5024 x Nr)

The Level 2 FITS file has a primary data unit which contains the bias-subtracted, flattened image (or image cube in the case of pan frame) plus 4 extensions. Extension 1 is the bias-subtracted, flattened, distortion-removed image (or image cube). Extension 2 is an array with the per pixel error of the bias-subtracted, flattened, distortion-removed image (or image cube). Extension 3 is an array with a data quality flag for each pixel of the bias-subtracted, flattened, distortion-removed image (or image cube).

Table 10.2 Pan Frame Image Data Format
FITS Data Unit Dimension Description
Primary 5024 x 128 x Ni Bias-subtracted and flattened image cube
Extension 1 5024 x 128 x Ni Bias-subtracted, flattened, distortion-removed image cube
Extension 2 5024 x 128 x Ni 1-sigma error per pixel in extension 1 image
Extension 3 5024 x 128 x Ni Data quality flag of extension 1 image

Table 10.3 TDI Image Data Format
FITS Data Unit Dimension Description
Primary 5024 x Nr Bias-subtracted and flattened image cube
Extension 1 5024 x Nr Bias-subtracted, flattened, distortion-removed image cube
Extension 2 5024 x Nr 1-sigma error per pixel in extension 1 image
Extension 3 5024 x Nr Data quality flag of extension 1 image


If IMG2PNG can output all the images it would be loverly. But maybe that's asking too much. Doesn't keep me from asking though

--Emily

[Bjorn Jonsson]

Thanks - seems to be exactly what I need.

If IMG2PNG can output all the images it would be loverly. But maybe that's asking too much. Doesn't keep me from asking though

It already does . A number gets added to the name of the output file to distinguish between the images.

[peter59]

(1) Does anyone know what those three images in each of the LORRI files are? The first two look similar but most (all?) of the pixels in the third one are of uniform brightness.

(2) The MVIC files contain four images. I haven't looked closely at them yet but the fourth one seems very uniform (the resulting PNGs are small, meaning it compresses well). Is it correct that images 3 and 4 contain information on errors and data quality as was stated in an earlier messages in this thread? Image 3 looks like a 'real' image so I'm a bit surprised if this is the case.

Please open whatever (MVIC, LORRI, Alice, SWAP) NH's file using program "Fv viewer" and all will be clear.

LORRI


ALICE

[MarcF]

I just realize that there are two versions of the "Io-Europa crescents Kodak moment picture":

http://pluto.jhuapl.edu/gallery/sciencePho...pics/040207.jpg

and

http://pluto.jhuapl.edu/gallery/sciencePho...pics/101607.jpg

The second version has an improved resolution (LORRI), and the two moons positions are quite different.
Is this reflecting the real movement of the moons between the times when the MVIC and LORRI pictures were taken ?
Marc.

[Spirit]

Based on the results from the Voyagers and from NH's SDC instrument, could we calculate what's the friction all the way to Pluto and beyond and how much delta-v will NH loose due to that friction? I know friction in space is negligible, but given that NH will travel "consciously" for at least 10 years (hopefully even more), this should accumulate. The Voyagers have been traveling for some 30 years now and they should have sensed it even more.

[Mongo]

Based on the results from the Voyagers and from NH's SDC instrument, could we calculate what's the friction all the way to Pluto and beyond and how much delta-v will NH loose due to that friction? I know friction in space is negligible, but given that NH will travel "consciously" for at least 10 years (hopefully even more), this should accumulate. The Voyagers have been traveling for some 30 years now and they should have sensed it even more.

Actually, I would expect that any effect due to 'friction' would work in the opposite direction, since the solar wind is moving outward more quickly than NH.

Although any effect is doubtless tiny.