Astrogeology Science Center

Sol 37 update on Curiosity from USGS Scientist Ken Herkenhoff: Planning Under a Fake Sun

13 September 2012

The ChemCam instrument was confirmed to be safe, but will not be used again until Friday to give the ChemCam team a chance to rest and regroup. The team met at the end of the planning day (7:30 PDT) to review the data received so far and to plan the next steps. By the time of this meeting I had been up all night, so I was pretty tired but it was a good meeting, and kept me off the freeway until rush hour traffic cleared a bit.

It was my last shift as MAHLI/MARDI Payload Uplink Lead this week, and ended up being fairly busy because the MSL science team requested more MARDI images at various times of day to see how useful the images are under different illumination conditions. We were also able to plan one image at exactly the same time of day as one taken on Sol 32, to look for changes on the surface due to winds. So I sat down with one of the rover planners to look at how much the rover shadows the MARDI field of view at various times of day. I always enjoy working with the rover planners because their visualization tools are so COOL. They allow a model of the rover to be placed on the 3-D terrain derived from stereo images and illuminated by a fake sun. This model showed that the MARDI images would be partly shadowed until 15:00, when only a corner of the images would be shadowed by the left front rover wheel. So we planned a couple images in the late afternoon and one earlier to span the range of illumination. Based on the preliminary results of the compression testing I've been doing, I recommended more compression of the fully-illuminated images, to reduce data volume without sacrificing image quality. Details in shadows are more difficult to preserve when the image is compressed, so we left the partly-shadowed image at the default (minimal) compression.

Although I'm not staffed in a tactical role for a few days, I plan to stay involved in tactical operations on Mars time, as shifting between Earth and Mars time is difficult these days.

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