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Robert Ergun University of Colorado. MMS Burst System SWT Report Revised (9/12/2011). Burst Memory Management. Basic Plan: Obtain ~20 minutes of burst per day . Phase 1 orbit: ~1 day -> 20 min. burst data. Phase 2 orbit: ~3 days -> 1 hour of burst data. Burst Memory Management.
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Robert Ergun University of Colorado MMS Burst System SWT Report Revised (9/12/2011)
Burst Memory Management • Basic Plan: Obtain ~20 minutes of burst per day. • Phase 1 orbit: ~1 day -> 20 min. burst data. • Phase 2 orbit: ~3 days -> 1 hour of burst data.
Burst Memory Management • The four main elements of burst system are: • Instruments must produce four types of data: • Slow Survey • Fast Survey • Burst Data • Trigger Data • The CIDP must have the capability to store (on-board) the high-time resolution data in the regions of scientific interest on each of the SC for an entire orbit. • The science team must implement a method to select the allocated volume of high-time resolution data (resulting in an average of ~2.7 Gbit/day) for transmission to the ground. • The MOC/SOC must manage the burst memory to transmit the selected data and free unwanted data.
Burst Memory Management The four main elements of burst system are: • Instruments must produce four types of data: • Slow Survey • Fast Survey • Burst Data • Trigger Data • The CIDP must have the capability to store (on-board) the high-time resolution data in the regions of scientific interest on each of the SC for an entire orbit. • The science team must implement a method to select the allocated volume of high-time resolution data (resulting in an average of ~2.7 Gbit/day) for transmission to the ground. • The MOC/SOC must manage the burst memory to transmit the selected data and free unwanted data. Complete Complete In Progress In Progress
Burst Data Selection • Trigger Data: • About 32 quantities per SC generated by instruments every 10 seconds. • Trigger data are indicators of a reconnection event. Trigger Data CDQ • CDQ (Cycle Data Quality): • The CDQ is derived from the trigger data. It represents the burst data quality for each SC. • The CDQ is generated by CIDP every 10 seconds. MDQ FOM • MDQ (Mission Data Quality): • A quantity representing the data quality from all four SC. • The MDQ generated on ground every 10 s by combining the four CDQ quantities. Held Data
Burst Data Selection • FOM (Figure of Merit): • A quantity representing the data quality of a Burst Segment. • A burst segment consists of N 10 s burst buffers. • The FOM and length of Burst Segments are calculated from the MDQs. • The FOM are used to select the burst data for transmission. Trigger Data CDQ MDQ • Held Data: • The Burst Segments with the highest FOMs will be saved on board. • The Burst Segments are transmitted in order of the highest FOM to lower FOM. Priority will be given to completely transmit Burst Segments from all SC. FOM Held Data
Burst Data Selection Automatic Selection (SOC) Buffer Selection Command Generation Weight Tables Burst Metadata (CDQs) Calculate MDQ Calculate FOM Trigger Data Slow Survey Data SITL Selection View Data Select Intervals Calculate FOM SITL Auto SITL Tables Process Survey And Trigger Data Calculate FOM
Burst Data Selection Path 1: Automatic Automatic Selection (SOC) Buffer Selection Command Generation Weight Tables Burst Metadata (CDQs) Calculate MDQ Calculate FOM Trigger Data Slow Survey Data SITL Selection View Data Select Intervals Calculate FOM SITL Auto SITL Tables Process Survey And Trigger Data Calculate FOM
Automatic Routine Status SDC has incorporated and tested IDL code for MDQ calculation. Default MDQ tables NOT defined. SDC has incorporated and tested IDL code for FOM calculation. Default FOM tables are defined. Further testing is planned.
Burst Data Selection Path 2: SITL Automatic Selection (SOC) Buffer Selection Command Generation Weight Tables Burst Metadata (CDQs) Calculate MDQ Calculate FOM Trigger Data Slow Survey Data SITL Selection View Data Select Intervals Calculate FOM SITL Auto SITL Tables Process Survey And Trigger Data Calculate FOM
Burst Data Selection Path 2: SITL Auto Automatic Selection (SOC) Buffer Selection Command Generation Weight Tables Burst Metadata (CDQs) Calculate MDQ Calculate FOM Trigger Data Slow Survey Data SITL Selection View Data Select Intervals Calculate FOM SITL Auto SITL Tables Process Survey And Trigger Data Calculate FOM
Automatic Routine Status SITL code displayed in January, 2012. SITL interface to SOC being defined. A “FOM structure” will be passed between SOC and SITL scientists. Details to be worked out by summer 2013. SITL software to be available to UCB (TPLOT developer) by March, 2013.
Burst Data Selection Scientists may “tune” tables. Automatic Selection (SOC) Buffer Selection Command Generation Weight Tables Burst Metadata (CDQs) Calculate MDQ Calculate FOM Trigger Data Slow Survey Data SITL Selection View Data Select Intervals Calculate FOM SITL Auto SITL Tables Process Survey And Trigger Data Calculate FOM
Science Management • “Operating” or “Burst” Scientist • The PI will delegate the data selection task to a “Burst” Scientist who is responsible for the day-to-day operation of the MMS mission. This position should be a rotating position. • The Burst Scientist will have several deputies. The basic idea is to have a mixture of young scientists and “experienced” scientists. • I recommend that one of the deputies becomes the next Burst Scientist. • The Burst Scientist will be the single point of contact to the SOC/MOC for burst system management. • The Burst Scientist may employ the aid of instrument leads and the MMS theory group in making burst data decisions.
Science Management • Automatic Selection Algorithm: • I recommend that the Burst Scientist also have the authority to alter the burst tables and automatic selection algorithm to “train” the automatic algorithm to make better selections. • The ultimate goal is to have the burst selection to be automatic.
Burst Data Selection Science Criteria for selecting burst events.
Trigger Data FIELDS produces 16 quantities including magnetic field levels and fluctuations, density and density fluctuations, and electric field and wave activity monitors. FPI produces 11 quantities including electron fluxes, ion fluxes, and variability. HPCA produces 2 quantities including H+ and O+ fluxes. EPD produces 5 quantities including high-energy electron and ion anisotropy and variability.
Trigger Data CDQ (Cycle Data Quality) Calculation (made on-board and by the SOC). For each 10 s “page” (and for each SC), the TDNs (trigger data) are combined with a table-driven formula:
Trigger Data (Defaults) T/S T/S Primary Tail Secondary S T/S T/S T/S T/S T/S T/S T/S S Primary Subsolar T - Tail S - Subsolar
Trigger Data (Defaults) Primary Subsolar T T/S T/S Primary Subsolar T
Trigger Data (Defaults) T/S T/S T/S