1. Goal : Setup and monitor “chambers” with resolution of  < 200  m Demonstrate System Redundancy Test Setup : 1 SLM Line (2 Laser Redundancy) 1 Transfer Line (Single Laser) 1 Transfer Plate Analog Sensors (Temp, Proximity) Data Analysis : 1500+ Events Reconstructed 3 Test Periods (July, Aug, Sept 2000) New Analysis Software : CMS Object oriented Code for Optical Alignment (COCOA) Prototype Reconstruction Software Used EMU Alignment ISR Prototype System Test June-Sept 2000 at CERN ISR Tunnel

2. Assumptions : Sensors et2, et3, and es10 are known (In practice, es9 is used due to potential survey errors in es10) 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

3. Final ISR 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) Final Results : System  = 133  m Typical Reconstructions within 300  m of expected survey location Sensors outside 300  m range have understood errors

4. Reconstruction Dominated By Survey Errors Estimated Survey Errors 60  m local  120  m global Errors in COCOA Reconstruction 220  m Systematic Errors  < 15  m Statistical Errors (1500 Events) General Remarks Reconstruction is roughly independent of laser choice (within error) Reconstruction is independent of laser motions 4 CCD measurements on reference Sensors will be critical (we had 3) ISR Reconstruction Results Conclusions

5. COCOA Simulation Goals Create Model CMS EMU Alignment System –DCOPS + Analog Sensors Evaluate Intrinsic System Errors –Chamber construction –System design Evaluate System Performance –Intrinsic Resolution –Correlation of System Components –Effects from component failure Provide ‘First Draft’ of EMU Alignment Reconstruction Software Integration of Results into General Physics Simulation

6. Current Status (May 2001) Substantial Software Improvements Extraction of Component Data from CMS Production Drawings (Complete) Endcap CSC and SLM Lines have been modeled COCOA Simulation ME2/3/4 COCOA ModelSimulated SLM Line