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Dec 1, 2012 1 FIELDS Top Level Requirements Review S. Harris (UCB)
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Dec 1, 2012 Level 1 Requirements for SPP (for FIELDS) FIELDS Investigation description This investigation will make direct measurements of electric and magnetic fields and waves, Poynting flux, absolute plasma density and electron temperature, spacecraft floating potential and density fluctuations, and radio emissions. For Baseline Science, SPP will: –Measure magnetic and electric fields, their fluctuations and variations with sufficient cadence and sensitivity to identify and characterize solar wind structures (shocks, current sheets, discontinuities, and CMEs) –Analyze fluctuations and turbulence down to the dissipation range –Identify and quantify energy flux in the waves thought responsible for coronal and solar wind heating –Measure interplanetary radio emission with sufficient sensitivity and time resolution to resolve signatures of microflare coronal heating –Baseline measurements, shall be made at least between 9.5 Rs and 55 Rs: 2
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Dec 1, 2012 Level 1 Requirements, continued For Threshold Science (minimum design requirements) –Threshold shall be met by making reduced capability measurements during first solar pass reaching 9.5 Rs and at least 500 hours within 20 Rs –Required threshold measurements: 3
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Dec 1, 2012 Level 2 Requirements for SPP FIELDS-Centric L2 Requirements… Make measurements as described in L1 Baseline Complete at least three orbits with Perihelion < 10 Rs S/C must Accommodate: –4 electric field antennas –2 fluxgate magnetometers –One 3-axis search coil magnetometer S/C is required to provide thruster indicator to instruments Absolute time knowledge accuracy for FIELDS is ±1 sec (3 ) –After post processing on the ground S/C is required to reorient S/C to support calibration and provide real time telemetry during commissioning S/C pointing control, alignment, knowledge (for FIELDS) is 3° – Other instruments are tighter, WISPR requires 1° pointing – Mission req’t is pointing knowledge wrt Sun center: better than 1° (3 ) S/C required to dowlink avg of 85 Gbits science data / orbit – FIELDS allocation is currently 20Gbits/orbit, avg rate of 26kbps 4
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Dec 1, 2012 Level 3 Payload Requirements - MAG MAG Requirements… –Bandwidth required is lower than planned MAG performance –Two ranges specified: 65536nT and 4096nT –Sensitivity is consistent with GSFC MAG performance –Accuracy specified to 5nT –3D vectors specified –Solar distances 9.5 Rs to 0.25AU (shows up on all requirements) 5 Requirement Rationale
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Dec 1, 2012 Level 3 Payload Requirements - SCM SCM requirements… –Performance based on a FIELDS presentation of 8/10/2012 “FIELDS_EMC_summary_120810.pdf” Stuart Bale –Accuracy specified to 1dB –3D vectors specified 6 Requirement Rationale
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Dec 1, 2012 Level 3 Payload Requirements – DFB Survey Measurement requirements for DFB Survey… –SCM not included –32 samples/s –Two orthogonal directions 7 The Plasma Wave Investigation shall provide electric fields measurements for MHD Scale Physics (DFB Survey Mode) for solar orbital distances of 9.5 Rs to 0.25 AU, as follows: -- cadence of 32 samples/s (Nyquist frequency of 16 Hz) [TBR]; -- magnitude range: 0 to 500 mV/m [TBR]; -- sensitivity of 1 mV/m [TBR]; -- in two orthogonal directions Requirement
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Dec 1, 2012 Level 3 Payload Req. – DFB Burst Mode 1 Measurement requirements for DFB Burst Mode 1… –SCM not included –256 samples/s –Dynamic range: 140dB (7 decades) –Sensitivity: 100 µV/m / √Hz at 75Hz –Two orthogonal directions 8 The Plasma Wave Investigation shall provide electric fields measurements for Ion Scale Physics (DFB Burst Mode 1) for solar orbital distances of 9.5 Rs to 0.25 AU, as follows: -- cadence of 256 samples/s (Nyquist frequency of 128 Hz)[TBR]; -- dynamic range of 140 dB [TBR]; -- sensitivity of 1 x 10^(-4) V/m/√Hz at 75 Hz [TBR] -- in two orthogonal directions Requirement
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Dec 1, 2012 Level 3 Payload Req. – DFB Burst Mode 2 Measurement requirements for DFB Burst Mode 2… –SCM not included –128k samples/s –Dynamic range: 140dB (7 decades) –Sensitivity: 1 µV/m / √Hz at 3.5kHz –Two orthogonal directions 9 The Plasma Wave Investigation shall provide electric fields measurements for Electron Scale Physics (DFB Burst Mode 2), for solar orbital distance of 9.5 Rs to 0.25 AU, as follows: -- cadence of 128k samples/s (Nyquist frequency of 64 KHz) [TBR]; -- dynamic range of 140 dB [TBR]; -- sensitivity of 1 x 10^(-6) V/m/√Hz at 3.5 kHz [TBR] -- in two orthogonal directions Requirement
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Dec 1, 2012 Level 3 Payload Req. – TDS Burst Mode Measurement requirements for TDS Burst Mode… –SCM not included –2M samples/s –Dynamic range: 140dB (7 decades) –Sensitivity: 0.1 µV/m / √Hz at 100kHz –Two orthogonal directions 10 The Plasma Wave Investigation shall provide electric fields measurements for Microphysics (TDS Burst Mode) for solar orbital distances of 9.5 Rs to 0.25 AU, as follows: -- cadence of 2 M samples/sec (Nyquist frequency of 1 M Hz) [TBR]; -- dynamic range of 140 dB [TBR]; -- sensitivity of 1 x 10^(-7) V/m/√Hz at 100 kHz [TBR] -- in two orthogonal directions Requirement
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Dec 1, 2012 Level 3 Payload Req. – DFB Spectral Mode Measurement requirements for DFB Spectra… –1 spectra/s, 1Hz to 64kHz (in variance with DFB expectation?) –Dynamic range: 140dB –Two orthogonal directions –No specification for resolution 11 The Plasma Wave Investigation shall provide electric fields measurements for Turbulence/Wave Spectra (DFB Spectral Mode) for solar orbital distances of 9.5 Rs to 0.25 AU, as follows: -- cadence of 1 spectrum/sec [TBR]; -- frequency range of 1Hz to 64 kHz; -- dynamic range of 140 dB [TBR]; -- sensitivity of (1) 1 x10^(-4) V/m/√Hz at 75 Hz [TBR]; (2) 1 x10^(-6) V/m/√Hz at 3.5 KHz [TBR]; -- in two orthogonal directions Requirement
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Dec 1, 2012 Level 3 Payload Req. – QTN Spectroscopy Measurement requirements for QTN Spectra… –1 spectra/4s, 10Hz to 2.5MHz –Dynamic range: 100dB –Two orthogonal directions –No specification for resolution 12 The Plasma Wave Investigation shall provide electric fields measurements for QTN Spectroscopy (TNR/HFR Survey Mode) for solar orbital distances of 9.5 Rs to 0.25 AU, as follows: -- cadence of 1 spectrum / 4 sec [TBR]; -- frequency range of 10 kHz to 2.50 MHz; -- dynamic range of 100 dB [TBR]; -- sensitivity of 2 x 10^(-7) V/m/√Hz at 1 MHz [TBR]; -- in two orthogonal directions Requirement
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Dec 1, 2012 Level 3 Payload Req. – Radio Emissions Measurement requirements for Radio Frequency Spectra… –1 spectra/16s, 1MHz to 16MHz (in variance with DFB expectation?) –Dynamic range: 80dB –Two orthogonal directions –No specification for resolution 13 The Plasma Wave Investigation shall provide electric fields measurements for Radio Emissions (TNR/HFR Survey Mode) for solar orbital distances of 9.5 Rs to 0.25 AU, as follows: -- cadence of 1 spectrum / 16 sec [TBR]; -- frequency range of 1 MHz to 16 MHz; -- dynamic range of 80 dB [TBR]; -- sensitivity of 1 x 10^(-7) V/m/√Hz at 10 MHz [TBR]; -- in two orthogonal directions Requirement
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Dec 1, 2012 Other Level 3 Payload Req. – Some highlights Provide at least 3 orbits of science measurements reaching perihelion distance of 9.5 Rs Provide at least 950 hours of measurements below 20 Rs Operational lifetime of 7 years after launch Accommodate in-flight calibration FIELDS shall participate in system-wide burst mode –Share limited amount on instrument messaging for coordinating burst –Share status packets at 1Hz that includes status and burst data Receive/react to S/C time/status packet –Includes burst flags, shared burst data, MET, S/C status indicators –e.g. thruster status, SSR status, distance from sun, power down req. FIELDS shall provide for exchange of data with SWEAP Limit internal timing uncertainty to ±1ms Limit total internal alignment error < 1 ° (dynamic + static) FIELDS shall implement time-tagged command functionality, if req’d. Antennas shall provide features to compensate for TPS shifts Survive and/or meet L3 performance during Solar Storm events 14
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