For your fun and enjoyment, a new Jim'n'Doug show!

http://www.planetary.org/explore/topics/ma...vers/audio.html

--Emily

Now we know the identity of the mystery man!
And so nice to see you posting again, Emily. And really nice to see your beautiful new avatar....

Thanks!

PS - the actual data volume for the McMurdo is 3.92 Gbits That's something like 5-6 weeks of Odyssey downlink of pure Pancam.

Doug

He appears to be looking for the perfect spot for the next UMSF BBQ.

Holy Moses! That was an incredible interview. The questions were perfect and the answers were wonderfully insightful. Possibly your best interview ever, Doug and Jim. I am still overwhelmed by the amount of new information. I think it is the first one where I felt compelled to take detailed notes.

There is too much to comment on tonight, but thanks for asking about the pancam resolution. It seems that Jim gave us quite a detailed answer to that one. I also enjoyed his mention of this time as a vacation for the overworked team. They certainly deserve a vacation. I will take issue with his comment that we have more free time to look at the data. They are paid to analyze the data during working hours, and any free time is likely to be the same between them and us. In fact, it would appear that quite a number of us are shaving time from our day jobs to keep up with these missions.

That was really a welcomed insight into the thoughts of the mission commanders. I have a couple of dozen other things I wanted to mention, but it is too late for me, and they belong in other threads. I don't know how you guys could have packed more information into those minutes.

Look your step, Doug!

I really appreciated that answer - it explains a lot. The entire interview was excellent too very much appreciated Doug (and Jim)

Thanks for the nice comments - I was feeling a bit rough (I'd had an astronomical injury.....don't ask) when I did it, and Jim and I were wondering if people were still interested.... I fwd'd on these comments to him, and I think I share his response

"I'm glad that some people continue to enjoy these chats. I enjoy them immensely."

So do I, and one day, I'll do one that uses a mini-disc recorder and not 3000 miles of internet lag

Doug

Just a quick follow-on to the sun-finding accuracy: while the precision of finding the solar disk within an image can be good to half a pixel as Jim mentioned, the pointing accuracy of the camera masthead is rather worse. I forget the exact figure, but as I recall the relative pointing accuracy of the pancam masthead was something like 0.1 degrees (a minor limitation for automated panorama stitching programs). The overall orientation determination combines the sun-finder results with internal vehicle level data, which has some additional error. Finally the sun-finding algorithm is only performed at major sites, rather than following every drive, and in between the vehicle's self-orientation knowlege may drift up to around 1.5 degrees.

I see no reason why it wouldn't / couldn't be done with every tau observation which means almost every single sol.

Doug

My turn to thank you Doug. I finaly had the chance to listen to the MP3 file.
I had some emotions when you asked "my" question about the feeling of seen the mast's shadow on the view from MRO. I realised that Jim share this (at least, the view of Oppy still roving) with Steve even much more than I thought. They form quite a team.

I'm not sure about how it ties-in with tau observations, however with regard to its application to the periodic re-calibration of the rover's orientation quaternion, the mission documentation states that this is performed only at major sites, rather than every Sol. Some time ago when I was trying to use the visible northern rim of Big Crater as a navigation reference this drift became very evident.

Perhaps rover orientation is only updated for driving/imaging etc at each new site number. I would have thought that they would use any and every orientation update possible ( and any sun observation would be able to do this ) - if for no other reason than good HGA pointing for uplink each morning.

Doug

My recollection is that the HGA only requires something like +/- 2.5 degrees precision in pointing, and the drift in the rover orientation quaternion stays well within that over multiple drives. It would certainly simplify navigation from my perspective if they would recalibrate daily, as even half a degree of drift complicates long baseline photogrammetry.