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ECEG287 Optical Detection Course Notes Part 14: SNR Analysis. Profs. Charles A. DiMarzio and Stephen W. McKnight Northeastern University, Spring 2004. SNR Layout for Direct Detection. Filter. Amp. Preamp. P s. BPF. P BKG. Johnson. Johnson. Direct-Detection SNR Summary.
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ECEG287 Optical Detection Course NotesPart 14: SNR Analysis Profs. Charles A. DiMarzio and Stephen W. McKnight Northeastern University, Spring 2004 Charles A. DiMarzio, Northeastern University
SNR Layout for Direct Detection Filter Amp Preamp Ps BPF PBKG Charles A. DiMarzio, Northeastern University
Johnson Johnson Direct-Detection SNR Summary Direct 1MHz Direct 1GHz 0 Sig Sig -10 -20 -30 -40 -50 -60 Quantum -70 D* -80 300K Bkg -90 Quantum Sunlit Bkg -100 D* -110 300K Bkg -120 Charles A. DiMarzio, Northeastern University Sunlit Bkg
SNR Layout for Coherent Detection PLO Filter? Amp Preamp Ps BPF PBKG Charles A. DiMarzio, Northeastern University
Johnson Johnson Johnson SNR Summary Direct 1MHz Coherent 1GHz Coherent 100kHz Direct 1GHz 0 Sig Sig -10 Sig Sig -20 -30 -40 -50 Quantum -60 Johnson Quantum -70 D* D* -80 300K Bkg 300K Bkg -90 Quantum Sunlit Bkg Sunlit Bkg -100 Quantum D* 300K Bkg -110 300K Bkg Sunlit Bkg -120 Charles A. DiMarzio, Northeastern University Sunlit Bkg
Detection Statistics • Determine Probability Density Distributions • Noise • Signal with Noise • Assume a Threshold, t • Calculate Probability of False Alarm, Pfa • Calculate Probabiliity of Detection, Pd • Plot Pdvs.Pfa, Varying t Charles A. DiMarzio, Northeastern University
Incoherent Noise Statistics Charles A. DiMarzio, Northeastern University
Incoherent Signal Statistics SNR=4 SNR=9 Charles A. DiMarzio, Northeastern University
Incoherent Detection Statistics Charles A. DiMarzio, Northeastern University
Coherent Detection • Field Statistics • Complex Gaussian • Zero Mean • Real and Imaginary Parts Uncorrelated • Magnitude of the Field • Rayleigh • Power • Negative Exponential Charles A. DiMarzio, Northeastern University
Coherent PDF’s Charles A. DiMarzio, Northeastern University
Coherent Signal Statistics SNR=4 coh Noise SNR=9 inc SNR=9 coh SNR=4 inc SNR=4 coh Charles A. DiMarzio, Northeastern University