Goal : Setup and monitor “chambers” with resolution of < 200  m Demonstrate System Redundancy Test Setup : 1 SLM Line 1 Transfer Line 1 Transfer Plate Analog Sensors (Temp, Proximity) Analysis : Events Taken Events Reconstructed Conclusions are not final … … but we are close ! Test of EMU ISR System June-Sept 2000 at CERN ISR Tunnel

Assumptions : Sensors et2, et3, and es10 are known Transfer Plate definition is defined Rotations of sensors are known within error limits of photogrammetry Prototype Test Setup June-Sept 2000 at CERN ISR Tunnel

SLM Line (Laser 302) Results of COCOA Reconstruction for July/August and September Runs Using es10 as the Final Reference Sensor SLM Line (Laser 303) Results of COCOA Reconstruction for July/August and September Runs Using es10 as the Final Reference Sensor COCOA Reconstruction Results (ISR Test Results – es10 Reference)

SLM Line (Laser 302) Results of COCOA Reconstruction for July/August and September Runs Using es9 as the Final Reference Sensor SLM Line (Laser 303) Results of COCOA Reconstruction for July/August and September Runs Using es9 as the Final Reference Sensor COCOA Reconstruction Results (ISR Test Results – es9 Reconstruction)

Sample September Laser 302 Results (1 sensor) Sample September Laser 303 Results (1 sensor) COCOA Reconstruction Results (ISR Test Results – es9 Reconstruction)

Note : Large survey errors 60  m local  120  m global ~ 220  m Systematic Errors < 15  m Statistical Errors General Conclusions : 4 CCD measurements on reference Sensors are critical Reconstruction is roughly independent of laser choice (within error) Reconstruction is independent of laser motions COCOA Reconstruction Results General Remarks

Distribution of raw CCD means in es4 during the July/August Run. Jump of 30 pixels = 420  m Distribution of COCOA Reconstructed location of es4 in the ISR hall during the July/August Run. (  y = 10  m,  z = 8  m) Conclusion : Shift in Laser not seen in Reconstruction 30 pixels COCOA Reconstruction Results (Laser Independence)

COCOA Reconstruction Results Thoughts on COCOA Comparison of COCOA Results to ‘Hand Calculations’ –We have verified operation in simple EMU type systems to < 100  m –We cannot verify in ISR EMU system to <400  m (rotations, calibration errors, transfer plate errors) Evidence of COCOA Accuracy –Prediction of et3 dowel location direct from PG agrees within 10  m from CERN PG group determination –Prediction of et1-es1 separation on Transfer Plate within 30  m of CMM determination (full EMU simulation) Concerns –Convergence of fit to local minima (false solutions) –Degenerate rotations possible

COCOA Reconstruction Results The Bottom Line (March 2001) We can demonstrate reconstruction of sensor positions within 220  m of CERN PG We can make redundant measurements Real CMS Data Can Be Better Than March 2001 Results –3 CCDs only on Reference Sensors (4 CCDs improve results) –Calibration Errors larger than expected, no calibration prior to installation (better results with better calibration) –More Constraints on COCOA Fits (Calibrated X-Hair Laser, Inclinometer Data on Transfer Plate)

Extra Slides

Sample September Laser 302 Results (1 sensor) Sample September Laser 303 Results (1 sensor) COCOA Reconstruction Results (ISR Test Results)

FLAP takes raw data and finds centroid of charge distribution in each CCD Laser Instability : CDD centroids were found to ‘jump’. Problem can be traced to laser diode. COCOA Reconstruction Results (Laser Independence)

FLAP Fitting Routines CCD Peaks in es9 from laser 302 … CCD Peaks in es9 from laser 303 taken immediately after laser 302 data…