MSL Images & Cameras, technical discussions of images, image processing and cameras Options

[CosmicRocker]

I'm still trying to figure out a number of things about the new images we are trying to work with. Assuming others are likewise trying to learn, I thought I would open this thread to create a place for such discussions.

I'd like to start out with a comment about raw image contrast. There have been several postings in the main threads about whether or not the MSL raw images have been stretched like those from the MER missions. I am certainly no expert on this, but it looks to me as if the MSL images have not been stretched at all. I haven't tried to analyze all of the image types, but the hazcams and navcams have pixel brightness histograms that are very different from their MER counterparts.

This attached image compares MER and MSL navcams along with their luminosity histograms.


The MSL images clearly are not using the entire, available range of brightness values, whereas the MER raws do. For this reason, the MSL raw images can usually be nicely enhanced by simply stretching the distribution of brightness across the full 256 value range.

[Winston]

The signal to noise ratio and information content of this forum is outstanding. Let me contribute a small bit by providing links to technical documents about some of the MSL cameras, documents I found in the process of researching the MSL's computer system and internal network (about which I found virtually nothing):

The Mars Science Laboratory Engineering Cameras
http://www-robotics.jpl.nasa.gov/publicati...ne/fulltext.pdf

THE MARS SCIENCE LABORATORY (MSL) NAVIGATION CAMERAS (NAVCAMS)
http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2738.pdf

THE MARS SCIENCE LABORATORY (MSL) HAZARD AVOIDANCE CAMERAS (HAZCAMS)
http://www.lpi.usra.edu/meetings/lpsc2012/pdf/2828.pdf

THE MARS SCIENCE LABORATORY (MSL) MARS DESCENT IMAGER (MARDI) FLIGHT INSTRUMENT
http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1199.pdf

THE MARS SCIENCE LABORATORY (MSL) MARS HAND LENS IMAGER (MAHLI) FLIGHT INSTRUMENT
http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1197.pdf

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Some interesting heat shield documents:

MEDLI System Design Review Project Overview
http://www.mrc.uidaho.edu/~atkinson/Senior...ct_Overview.pdf

Advances in Thermal Protection System Instrumentation for Atmospheric Entry Missions
http://www.mrc.uidaho.edu/~atkinson/ECE591...ntations/Fu.ppt

A relatively short but very interesting document about the engineering challenges of landing on Mars which discusses the advantages and disadvantages of the various possible methods:
http://www.engineeringchallenges.org/cms/7126/7622.aspx

As I said, I found virtually nothing about the Mars Compute Element (MCE) and the network(s) used within the lander to control MSL hardware (anyone know a good source, the more technical the better?), but I did find a tiny bit within this document starting on p41 where the electronics architecture is discussed. The bus used is redundant 2Mbps RS-422. The SAM uses BASIC keywords for its command language!:

The Sample Analysis at Mars Investigation and Instrument Suite
http://www.springerlink.com/content/p26510...08/fulltext.pdf

Excerpt:
The (SAM) CDH (Command and Data Handling) module (Fig.16) includes a number of functions. The CPU is the Coldfire CF5208 running at 20 MHz. The CDH (module) communicates with the Rover via redundant 2 Mbps high speed RS-422 serial bus along with a discrete interface (NMI).

In the SAM software description starting on p47, I found this interesting tidbit:
SAM’s command system is a radical departure from prior spaceflight instrumentation. SAM is a BASIC interpreter. Its native command language encompasses the complete set of BASIC language constructs—FOR-NEXT, DO-WHILE, IF-ENDIF, GOTO and GOSUB—as well as a large set of unique built-in commands to perform all the specific functions necessary to configure and operate the instrument in all its possible modes.

SAM’s commands, which are BASIC commands with SAM-specific commands built in, are transmitted in readable ASCII text. This eliminates the need for a binary translation layer within the instrument command flow, and makes it possible for operators to directly verify the commands being transmitted. There are more than 200 commands built in to the SAM BASIC script language.

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And even though this is just a NASA Press Kit, it is satisfyingly detailed technically on various MSL systems:
Mars Science Laboratory Landing
http://mars.jpl.nasa.gov/msl/news/pdfs/MSLLanding.pdf

And just for the heck of it, here's NASA's Viking Press Kit. How very far we have come, even with press kits:
http://mars.jpl.nasa.gov/msl/newsroom/presskits/viking.pdf