SEP/SIT software design / requirements

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SIT on-board event processing
Glenn Mason, Peter Walpole, Mihir
Desai University of Maryland Joe Dwyer Florida
Institute of Technology
SEP/SIT software design / requirements peer
review NASA-GSFC August 22, 2002
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• SIT software requirements specified separately
• very similar to SEP / HET requirements
• basic scheme similar to WIND/STEP instrument
  which used an 1802 microprocessor

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SIT ASSEMBLY
HVPS
Electronics Box
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(No Transcript)
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SIT Board Level Block Diagram
Unlatch
Cover
Board 1
UMd/GSFC
Logic/MISC/CPU IF
TELESCOPE
Board 2
UMd/GSFC
Energy Electronics
To/From CPU
Board 4
MPAe
TOF Analog Electronics
Board 3
MPAe
TOF Digital Electronics
GSFC/UMd
Motherboard
UCB
HVPS
TEST CONNECTOR
LV Interface
Low Voltages
SSD Bias
Housekeeping
SIT
8/15/02
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Event Processing Software
Fig 3.7 SIT SW requirements
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Time of Flight
Element Tracks (H - Fe)
Solid State Detector Energy
From SIT description
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From SIT description
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From SIT description
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From SIT description
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Matrix Rates
From SIT description
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Beacon Rates
From SIT description
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From SIT description
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Event Storage Algorithm For Telemetry
From SIT description
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From SIT description
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Computation of intensity from matrix rates
Ij intensity, T time (s), AW geometry
factor, e efficiency, DE energy window, MRj
matrix rate j counts
From SIT description
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Computation of intensity from pulse height data
(as before, plus N(0/1)j number of PHA events
of particular species energy of priority 0/1
N(0/1) total number of PHA events of priority
0/1 MR(1/2) matrix rate counts for priority 0/1
From SIT description
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From SIT description
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From SIT description
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MISC version of pulse height binning calculation
Solid state detector lookup table value
f_m (issd - K216 itof - Ktof216
216)(128/7) /216
Time-of-flight lookup table value
f_e ( - itof Ktof216) (5.5)216) 16
/216
constant
From SIT description
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Rate and priority matrix
From SIT description
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Matrix rate assignments
etc
etc
From SIT description
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Beacon rate assignments
From SIT description
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PHA Event contents
From SIT description
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PHA Packet format
From SIT description
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Rate Packet format
From SIT description
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Status

• Pseudo-SIT event table generated from WIND/STEP
  data (20K events)
• simple fortran routine to process data completed
  6/02 including
• lookup table
• matrix beacon rate assignments
• sample output of process events
• Kristin Wortman developing machine language
  version -- preliminary version is ready for
  testing