Tau Chart, Comparing both rovers Options

[djellison]

I visited this data early on, but there's 600+ sols worth now, so I've revisited it

I thought it would be interesting to comapre Tau values form both rovers at the same time - so to that end I added 21 to the sol number of each Opportunity tau observation to bring it in to line, within a sol, of Spirit observations.

What does it show? (remember to subtract 21 to get ACTUAL Opportunity Sol numbers)

Well - both rovers experience a large increase from around Sol 350-370, but for Opportunity it peaked briefly significantly higher. Spirit experienced two local events, 380 and 420, Opportunity a long, small peak around 450 and another, shorter one at 480, and the share the big spike at 510ish.

Interesting stuff anyway - when you match them up, time wise ( i.e. +21 on MERB sol numbers ) they match quite closely.

Doug

Attached File(s)

 MER_tau.pdf ( 369.71K ) Number of downloads: 554

 

[remcook]

sorry for my ignorance- tau=optical depth?

[helvick]

sorry for my ignorance- tau=optical depth?

Yep Tau is optical depth. Direct insolation is e(-tau)*top of atmosphere insolation. Indirect insolation is a whole other ball of wax. Generally correlates to some degree with atmospheric dust levels on mars. AFAIK it's dimensionless, like a coefficient of friction or drag.