1. SPP FIELDS DFB Sensitivity Performance Requirement Re-evaluation CU/LASP DFB Team 2015-04-07

2. Summary: Issue 1: SCM LF (< 60 kHz) noise floor just meets sensitivity requirement A) Leave design as-is B) Lower SCM top end by 2x Issue 2: E AC (200 Hz - 60 kHz) noise floor does not meet sensitivity requirement A) Raise sensitivity requirement by ~2x - ~6x B) Lower EAC top end by ~2x - ~6x C) Lower EAC top end by and raise sensitivity requirement Issue 3: Need to define signal coherence time for requirements - Allows spectral averaging + noise subtraction to meet req. - Suggest 1 NYs

3. Issue 1: SCM LF (< 60 kHz) noise floor DFB/SCM combined system just meets the sensitivity requirement at 3.5 kHz (after spectral averaging and noise subtraction) Need to: 1) Define a signal coherence time for this requirement - Suggest 1 NYs Possible Actions: A) Leave design as-is (saturation less likely) B) Lower SCM top end by 2x (improve signal-to-noise at low end)

4. Req. 3.5 kHz Current Performance w/ 3.8 nT/V (should be 2.6 nT/V)

5. Spectral averaging + noise subtraction (SCM)

7. Issue 2: E AC (200 Hz - 60 kHz) noise floor DFB/AEB/Preamp combined system does not meet sensitivity requirement at 30 kHz (after spectral averaging and noise subtraction) Need to: 1) Define a signal coherence time for this requirement - Suggest 1 NYs Possible Actions: A) Raise sensitivity requirement (saturation less likely) B) Lower EAC top end (improve signal-to-noise at low end) C) Lower EAC top end and raise sensitivity requirement Note: E AC 30 kHz sensitivity requirement is an extrapolation of 100 kHz L3 requirement into the DFB frequency range.

8. Req. 30 kHz Current Performance

9. Spectral averaging + noise subtraction (E-field)