BCAL Reconstruction Issues
From GlueXWiki
- Simulation (mcsmear)
- fADC timing
- Uses threshold crossing time rather than FPGA-ish algorithm
- Resolution is too poor
- mcsmear doesn't seem to smear data enough
- TDC timing resolution is too good
- single photo-electron peaks in energy spectrum
- spikes in time histogram at low energy
- max ADC amplitude (12 bits?)
- Sampling fluctuations not applied on per-particle basis
- Very low energy ADC hits coming from mcsmear
- fADC timing
- Timewalk corrections
- Establish procedure for doing these corrections based on simulated data (how closely should this match the correction procedure for real data?)
- Determine form of timewalk corrections
- What if we have TDC info only on one end?
- DBCALPoint (reconstructing E,z,t from double-ended hit)
- When determining energy, give more weight to higher energy hit? (also in averaging time?)
- Best way to determine sigma_z?
- How to deal with multiple hits in same channel?
- Clustering
- Use only timing information from fADCs?
- If we use TDC info also, we need to appropriately make use of the different timing errors of different hits
- Use only timing information from fADCs?
- Determining cluster properties (E, x, y, z, t)
- How to average cell-by-cell position to get cluster position
- Weight averages by...? E? E^2? 1/sigma^2?
- Average rectangular coordinates? Cylindrical? Spherical?
- Energy corrections (z-dependent, non-linear)
- Is current scheme good enough?
- If so, write a plugin to automate this process.
- Need extra special treatment of ends of calorimeter?
- How to determine errors (and correlations) on cluster properties (important for kinematic fitting)
- How to average cell-by-cell position to get cluster position