* Because the TMTS is significantly different from the OMCS, I started a new Mathematica model for it, based on the OMCS but with two (not four) blades at the top mass, blade lateral compliance at the top mass blades (just in case, because it's been important for quad blades in the past), and toe-out of the bottom wires in both the front-back and side-side directions (the front-back wire separation sl parameter has been forked to upper and lower values slu and sll). This can be found in the SUS SVN at ^/trunk/Common/MathematicaModels/DualLite2DBLateral .

* As is now my standard practice, I used the Mathematica version to export state space matrix elements in Matlab which I incorporated into the existing Matlab double model - if the flag pend.db is defined and non-zero, the ssmake2MBf.m file uses matrix elements for TMTS, otherwise it defaults to OMCS. The double model lives in the SVN at ^/trunk/Common/MatlabTools/DoubleModel_Production . I suspect there might be a tiny error in the way I allow for the wire stiffness in the Matlab arising from the tricky double toe-out of the bottom wires - the relative error between Matlab and Mathematica mode frequencies is better than 0.00007, but with other models I've routinely gotten 1E-12 or better. The exported matrix elements are correct because when used with no wire flexure correction (pend.stage2=0) they agree at the 3E-14 level with the Mathematica "Stage0A" results (also without wire stiffness). Any problem must be in the ssmake2MBf.m file. I'll revisit this as I have time and inspiration.

* I got Szymon to adapt the OMCS plotting scripts for TMTS ( ^/trunk/TMTS/Common/MatlabTools ) and take some test data (^/trunk/TMTS/H1/TMSY/SAGM1/Data/). Jeff K also helped. An issue we grappled with is that the Mathematica coordinate system is traditionally with +x normal to the plane of the top wires, whereas the natural coordinate system for use in MEDM screens has +L (longitudinal) in the cavity direction. So we put in a 90° rotation at a strategic point in the code.

* I started separate parameter sets for the first article and production builds: ^/trunk/Common/MatlabTools/DoubleModel_Productiontmtsopt_firstarticle.m etc). 

* I quizzed Ken Mailand for mass and MOI data for both first article and production builds. For ease of reference, I rearranged what he sent us and posted it at https://awiki.ligo-wa.caltech.edu/aLIGO/Suspensions/OpsManual/TMTS/Models .

* I got most of the rest of the parameters using the measure tool on the eDrawing at D0900419 for the first article. (The production version may well be different, but we haven't given it any attention yet.) To get the top mass d's (d0 and d1) I assumed the COM was 1.401" above the bottom surface of the bottom plate. To get the telescope d (d2) I assumed the coordinate origin was level with the round bars (where the marker seemed to be in the screenshot). This could very well be a few mm off.

* I put in blade lateral compliance the same as for the UIM blades in the quad model.

* With all of the above, the fit to TF data was pretty good except for the "R" (Mathematica "pitch") DOF. See the attachment at https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=6066 , especially p4. The fundamental R mode is predicted a bit too low, and the highest R mode is predicted a bit too high.

* To fix the fundamental R mode, I added a tweak of +4.3 mm to d1 (the blade d). This is plausible because that's what you would get if the blades were sitting a bit lower than expected, but the mismatch could also be due to stiff cabling. See https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=6239 . This tweak doesn't make any other modes significantly different, either better or worse. So the top R mode is still about 10% off, and I haven't been able to account for it in terms of plausible perturbations to parameters.

* A summary of the current best parameter set is on the aLIGO wiki at https://awiki.ligo-wa.caltech.edu/aLIGO/Suspensions/OpsManual/TMTS/Models/20130501TMTS_FirstArticle . Parameter values with comments giving sources are listed at the bottom. In particular, the flexure corrections are flex1 -> 0.00450482 and flex2 -> 0.00870794. Updated versions will be linked to from https://awiki.ligo-wa.caltech.edu/aLIGO/Suspensions/OpsManual/TMTS/Models .