Presentation on theme: "EFW Operational Modes RBSP SWG San Antonio September 2014."— Presentation transcript:
EFW Operational Modes RBSP SWG San Antonio September 2014
The principle operational modes of the EFW instrument involve 1) Biasing algorithms for different plasma conditions. The primary new algorithm is designed to improve probe performance during periods of negative spacecraft charging near dawn during super-intense electron injection events. 2) Modes involved in the collecting and playback of high time resolution burst data. a) Data rate (200 Hz to 16 ksamples/s) b) Measurement quantities (3E, 3 Bsc, Spacecraft potentia/density) c) Duration of bursts (5 seconds to 6 hours) d) Collection and Playback Criteria: Human intervention e) Targeted Science
Targeted Science and Associated Mode Present Mode: Major Storms, Injection Events, Large Amplitude Whistler Mode Waves, Non-linear parallel electric field structures. Probe A: Collection at 16 ksamples/s Quantities 3 E, 3 B, 6Vprobe Collection over +/- 2.5 hours of Apogee Decision on basis of survey plots, and information on storm from: Kyoto WDC real time Dst, ACE spaceweather forecast, and NOAA 3 day forecast, EFW survey plots. Playback intervals typically ½ hour to several hours depending on wave fields/ amplitude based on filter bank and spectral data in survey plots. One big event per several weeks– little info on plasmaspheric waves.
Probe B 1)Probe B Nominal Mode Same as A except sample at 4 ksamples/s Collect over +/-3 hours of apogee.. But during predicted storm interval collect over entire orbit ===================================================== 2) Close Conjuction Mode (3-4 days every 70 days) When the spacecraft are closely separated along orbit (several hundred to several thousand km ) we have been testing a "close conjunction mode). Probe B is placed in the exactly same Burst Mode as A described in previous slide. We target microphysics. large amplitude wave fields, kinetic Alfven waves. Ground Lightning Array (Holzworth, U. Wash) The world wide lightning network has coverage over much of the continental land masses, when the Van Allen Probes are magnetically conjugate to the.
Ground Lightning Array (Holzworth, U. Wash) The world wide lightning network has coverage over much of the global continental land mass, We recieve a prediction for intervals when the Van Allen Probes are magnetically conjugate to stations of the LDN from U. Wash.. This is typically 10-15 minutes of collection per day. Both Probes switched (if necessary) into 16 ksamples/s sampling rate. The data is collected. We then switch back into the "nominal mode' U. Wash determines which time intervals contain the most lighting strikes in near real time. We playback 5 minutes/day. (20% of burst TM allocation) Secondary priority Data is sacrificed if we need memory for a storm. EMFISIS collect ligntning data also.
BARREL Campaign Bursts Collect for several hours arround BARREL balloon conjunctions. Emphasize active periods. Sample rate 4 ksamples/s to 16 ksamples/s. Have targetted EMIC waves/ Whislter mode waves/Plasmaspheric Lower Hybrid Hiss. Great correlations between modulations in HIss over global plasmaspheric spatial regions and X-Rays seen by Balloons ( Breneman et al. in progress)
Equatorial Spread F Passes.( Pfaff) Sample Efields, Search Coil, Spacecraft potential/thermal plasma variations during Perigee pass during local dusk where Spread- F is observed. THEMIS ARRAY Conjunctions Bursting during passes over THEMIS ARRAY auroral streamer microphysics: mode is similar to nominal but conjugacy is a collection and playback criteria.