titles_tftm

                              Titles:  TFTM
                              =============
 
Contact:  N. Tagg, Guelph
 

 
Titles Files
------------
 
fitter.dat
 
 
Verification
------------
 
TFTM 1
------
 
Description
-----------
 
    This bank contains input data for the time fitter.
 
Data Words - TFTM 1
-------------------
 
        Fixed length Database Header.  See titles_dbhdr.html
 
        Data types: B(bit), I, F, D(double), H(hollerith 4 char)

 Type   Variable      [symbolic command]  Description
       in ftm_com/
 ----   --------      ------------------------------- 
 
1  I MinTubesAfterCut  [muon_fit_which_charge] Minimum number of tubes to attempt a fit. Fitter will
                       keep at least this many tubes to fit with.
 
2  I WhichCharge       [muon_fit_which_charge] Charge to use when analyzing tubes.
                       1=Qhs, 2=Qhl, 3=Qlx, 4=Max(Qhl,Qlx), 5=Qm (KPMT_QM)
 
3  I NumThrowAwayLast  [muon_fit_throw_away] Number of latest tubes to throw away.
 
4  I ExitGridPoints    [muon_fit_exit_guess_points] Points to grid-search near the estimated exit point.
                       Jitters the exit point on a hex grid.
                       More points increases computation time.
 
5  I DirGridPoints     [muon_fit_dir_guess_points] Points to grid-search in track direction.  More
                       points means more computation.  If more than 812 points
                       are selected, points are sampled randomly rather than
                       on a grid.
                                                                     (N*2+1)^2
6  I NumChopAtOnce     [muon_fit_cut_at_once] Number of tubes to chop at a time when improving fit
 
7  I NumChopMax        [muon_fit_max_cut] Maximum number of tubes to chop when improving fit
 
8  Reserved for future use
 
9  Reserved for future use
 
10 F ChargeMin         [muon_fit_min_charge] Minimum integrated charge.  Do not attempt to fit any
                       event with total charge less than CHARGEMIN.
 
11 F ChargeCutRatio    [muon_fit_charge_cut_ratio] For computing min charge to keep a tube. See Note 1.
 
12 F EtaGuessMin       [muon_fit_min_eta] Minimum zenith angle to search for on grid, radians.
                       See Note 2.
                       1.57 = Search only for downward going muons
                                                       ( pi/2 < eta < pi )
                       0.   = Search on all directions (  0   < eta < pi )
 
13 F ExitGridAngle     [muon_fit_exit_grid_angle] Width of grid spacing, degrees. Fitter searches
                       the theta,phi coordinates of the exit point on a
                       hex grid with a spacing of this angle.
 
14 F TimeWindow        [muon_fit_time_window] Time window of trial searches, ns.
                       Trial fit computes chisq/tubes for tubes where
                       |tfit-t| <window
 
15 F ChiSqGoal         [muon_fit_chisq_goal] Chi-squared per tube fitting goal
 
16 F FitToRadius       [muon_fit_enter_radius] Initial radius to fit to. (cm) See Note 2.
 
17 F WaterLevel        [muon_fit_water_level] Waterlevel z-coordinate (cm) for partial-fill fits.
 
18 F RMSMax            Upper limit on  RMS time.           
 
19 Reserved            Cheat word!
 
20 I DebugMsgs         [muon_fit_info/_debug] Flag to dump debugging messages to iqlog and iqprnt.
	               1 = informative, fit-by-fit results printed
	               2 = Progress messages, debugging only
 
21 I FileDump          [muon_fit_dump_files] Flag to dump text files (0=don't write, 1=write)
                       Intended for debugging/development work.  See code.
                       'ftm_chispace.dat' -> A map of every chisq value calculated
                                 for values t_exit, theta, phi, eta, psi
                       'ftm_tubes.dat'    -> A list of tubes in event with values
                                 calculated by fit.
 
22 I WhichTime         [muon_fit_multiphoton_time] Use of Multiphoton PCA times
                       != 1  Use regular PCA times (KPMT_PT)
                        = 1  Use Multiphoton PCA times (KPMT_PTM) 
 
23 I WhichSig          [muon_fit_mpca_time_sigma] Use of Multiphoton PCA PMT transit time RMS
                       != 1 Use TJITT (1.6ns) as Tube time sigma
                       = 1  Use MPCA PMT transit time RMS (KPMT_PTMS)

24 I ANxxPCAMask       ANxx PCA Mask.

25 I ANxxNuMask        ANxx NU Mask.
 
Notes
-----
 
1)   (Integrated Charge of Event) x (Charge Cut Ratio) = Q_cut.
     All tubes with Q < Q_cut are ignored by fitter.
 
2)   Fit position (ftxv bank) is at this radius. Since FTM fits only to a
     track, not a point, the start position of the particle is undefined.  FTM
     chooses a point at this radius to be the  fit vertex reported in the
     reconstruction.  This is useful particularly if the MC generates events in
     a shell with this radius.
 
3)   The fitter will ignore tubes with Z-coordinate greater than the given
     water level.  Tubes above the water will not recieve Cherenkov light on a
     wide cone, so these tubes are only confusing to the fitter.  Note that
     partial fill fits are much more susceptable to fitter inaccuracies, even
     with this fix. Set this value to be > 900 cm to ignore this feature.
 
 
TFTM 2
------
 
Description
-----------
 
This bank contains data used by the fitter, rather than control words.  This
data is used to search track directions in a consistent fashion.
 
Data Words
----------
 
Word 1 - Number of coordindinate pairs to follow
 
Words 2-1625- Theta-phi coordinates, in radians.
 
These are theta-phi coordinates of points 'evenly' spaced on a unit sphere.
Thanks to Bernie Nickel at U of Guelph for provding this.  The points
were found by first taking an isocohedron vertex coordinates, then subdiving
each face and projecting the subdivided grids back onto a sphere.  The result
is a set of 812 points, making a progressively finer grid.  The mean
angle between neihboring points is 8.36 degrees.