ISOC Update Outline

1
ISOC Update - Outline

• Top Level Requirements
• ISOC Organization
• Data Products and Flow
• Payload Operations
• Science Ops
• Energy/Spin Sweeps
• Acquisition
• Faux telemetry
• Interstellar O sensing
• On-orbit Calibration Trending
• Pressure measurement
• Gain testing
• Trending
• Archiving Distribution
• Top Level Schedule
• ISOC Labspace

2
Nomenclature
ACRONYMS

• Flight Software (FSW) SCB Software
• Payload Firmware (PLFW) CEU Software
• High Altitude Science Ops (HASO) (gt 10 Re)
• Low Altitude Housekeeping Ops (LAHO) (lt10 Re)
• State of Health (SOH) (SCB P/L) SOH
• Channel D IBEX-Hi background monitor
• Star Tracker SCB Star Tracker
• Star Sensor IBEX-Lo star sensor

SUBSYSTEMS
3
Top-Level ISOC Requirement

• To receive S/C data from the MOC and perform the
  following tasks
• Sequence data
• Identify data gaps and remove redundant data
• Process to higher level data products
• Archive and make data products available to the
  IBEX Science Team and the greater scientific
  community
• Also responsible for IBEX payload commanding
  (special ops), performance trending and parameter
  modifications over the course of the IBEX mission

4
ISOC Organization
Ops Lead Chelle Reno
ISOC Lead Nathan Schwadron BU (0.4 FTE)
Katie Goodrich, Sadia Hoq, Brian Stuart, Brent
Randol, Jamison Passuite BU (.33 FTE)
FTE Yearly Average
5
IBEX Data Flow
6
Orbit in the Life of the ISOC

• Command Loads
• Approve or Deny Command Load
• Provide STF to Orbital MOC (for special science
  maintenance operations)
• Receive copy of as-delivered upload
• Monitor near real-time SOH during pass using VNC
• Download raw back-orbit real-time data from the
  MOC SFTP site ingest into ISOC database
• Remove CCSDS headers (Level 0)
• Sequence data, identify data gaps remove
  redundant data (Level 0.5)
• Generate Level 0.5 data
• Includes derived fields such as spin phase, look
  direction, background as a function of look
  direction
• Accumulate Level 1 data into Level 2 maps
• perform magnetospheric/heliospheric segregation,
  separate species, find velocity direction,
  identify and cull any backgrounds
• Perform model-dependent corrections for Level 3
  data and accumulate into maps

7
Payload OperationsCommand Load Generation

• ISOC receives Orbit Events file from MOC
• For orbits where special science maintenance
  operations are desired, the ISOC generates an STF
• Pressure Measurement
• Gain Testing
• If no special operations are needed, integrated
  command load is generated by the MPS software in
  the MOC
• ISOC approves or declines the MOC-compiled ATS
  (Absolute Time Sequence) file
• ISOC receives copy of theas-delivered'' uplink
• 2 - 8 P/L commands per orbit
• P/L commanding is macro driven
• Variable parameters are set in Look Up Tables and
  called by macros
• Simplifies command load generation and validation

8
Payload Operations All Payload Commands
Used Every Orbit
9
PIGMI and Synthetic IBEX Data
10
PIGMI Software and Sky Coverage
11
Synthetic Data Flow

• Synthetic data will be routed through the CEU
  software to generate CCSDS telemetry stream
• Allows testing of scheme for data acquisition,
  harvesting, and packetizing
• S/W is being written now and will be extensively
  tested by BU students

12
Science AcquisitionHigh-Level Timeline
13
Science AcquisitionSpin-Level Detail (IBEX-Hi
Example)
14
Interstellar O-sensing Mode

• Does not happen in the first 6 months of science
  acquisition
• Restricted to - 30 deg from ecliptic
• Spring
• Use both high (3.5º FWHM) and low (7º FWHM)
  resolution sectors of the collimator for
  interstellar neutral observing
• For every 10-th spin, look at Energy bin 1 to
  identify any possible He counts
• For the other 9 spins use a single energy channel
  near 500 eV for O sensing
• Fall
• Reject particles from low resolution sectors
• Focus on Energy bins 2-3 (around 40 eV)

Ops Need Specification
15
Oxygen Sensing Mode
16
On-orbit Calibration Pressure Measurements (1
of 2)

• Pressure in ion gun region of sensors is a
  proxy for expected background
• Rest gas between collimator and conversion
  sub-system produces secondary ions via photo- and
  e-- impact ionization
• Pressure can be indirectly measured
• Negative e- rejection voltage is lowered in steps
  allowing a small e- current into the system, and
  enhanced e- impact ionization
• Pressure in the critical region behind the
  collimator can be deduced with reasonable
  accuracy for pressures above 10-8 Torr

17
On-orbit Calibration Pressure Measurements (2
of 2)

• Expected secondary ion rate and electron currents
  into the collimator as a function of rejection
  voltage for moderate and hot solar wind electron
  distributions with a pressure of 10-8 Torr in the
  region behind the collimator for a 1.5 keV ESA
  step

18
Gain Testing

• Track the MCP gain by the ratios of Triple to
  Double Coincidence Rates
• Ground Software will provide the ratios for
  trending
• Test Procedure that contains an automated series
  of internal stimulation settings, which
  completely tests the analog electronics
• Run once per month.
• David Hertzler is working on an automated check
  of this sequence

19
Trending

• Remainder of telemetry is housekeeping (H/K)
• Formatted to allow quick lookups base and stored
  in the telemetry database for easy
  cross-referencing
• Interpolation strategy TBD
• Heuristics to eliminate isolated noisy or
  unphysical values
• Trended quantities a topic for the April IBEX SWT

20
Archiving and Databases

• Two primary Databases
• Engineering SOH
• Trending
• SOH
• Searchable Database
• Science Database
• Telemetry to Maps
• C programs for data harvesting
• DEs and Histograms quality tagged
• Visualization toolbox (coordinate systems,
  overlays)

21
Archiving and Distribution

• ISOC (SwRI)
• Telemetry Archive
• Engineering SOH Archive
• Science Archive with web distribution of data
  products to science team
• BU
• Mirrored Science Archive
• SPDF and NSSDC
• Level 1,2,3 to SPDF for active archive (CDF
  format). The SPDF puts these on active archiving
  public sites such as CDAWeb, SSCWeb, and OMNIWeb
• IBEX will be a part of the Virtual Heliospheric
  Observatory (VHO), a new concept that allows
  users to interact with data that is stored at
  locations other than the SPDF CDAWeb. VHO is
  basically a search tool that will not house any
  actual data. To enable IBEX in the VHO, the ISOC
  plans to submit metadata to the SPDF identifying
  where various data products are retrievable.
• Validated Level 0, 1, 2, 3 data sent to NSSDC for
  permanent archive

22
ISOC Engineering SOH Archive

• Searchable Database
• Each APID has its own database table
• IBEX Database Backups
• 2 Linux Boxes in ISOC
• Backed up weekly
• Transcribed to tape and stored
• Backup database at Boston University

23
Science Processing Repository

• Telemetry is also processed using a series of C
  routines
• Sequence
• Remove redundant data
• Use ephemeris tables and pointing information
  (ancillary data) to derive position and attitude
• Perform binning, data harvesting
• Correlate DEs and Histograms
• Routines to plot in GSE, RA DEC, HSE coordinate
  systems
• Overlay magnetospheric projections
• Data is manipulated and harvested with a series
  of option flags for filtering
• data never removed
• Overlays include star maps, planets, the moon,
  magnetosphere, possibly bright comets
• Data storage not an issue
• data volume small Estimate of total data volume
  including data products and stored data
  reports, less than 50 GB

24
Top Level Schedule

• Faux Telemetry Scheme - 4/20/07
• S/W Build 1 - June/07
• Toolbox functions defined
• Level 0.5 Science S/W
• Level 0.5 P/L Firmware
• Command Load Defnt
• Flight Rules Constraints
• Mag and TS ENA Model
• Thermal test at SwRI - 7/15/07
• MOC I/F ISOC - 9/19-10/9/07
• Ground system I/F tests
• Mission PER - 10/24/07
• Grnd Network Data Flow Test - 12/20/07
• Test MOC I/F ISOC - 12/20/07 - 1/4/08
• ISOC/MOC Command Processing - 1/7-8/08
• S/W Build 2 (post-cal) - 1/7/08
• SCB Attitude Determination
• Cal Bkg Tables
• UV Star Table

• SWT - May/2008
• IBEX Ground Seg End-to-End - 5/23/08
• Rehearsals/tests - April-June/08
• S/W Build 4 (flight build) - 6/2/08
• Global Mapping S/W
• Aliveness test, CEU H9 Lo functional test,
  Initial rampup
• Web I/F, SOH Database
• S/W Build 5 (in flight) - 10/15/08
• Model dependent corrections
• Flux calculations
• Partial Results - 12/8/08
• Survey 6 Months - 1/15/09
• First mapping publication - 1/22/09
• Survey 12 months - 7/15/09
• ISOC S/W Build 6 - 7/15/09
• Survey 18 months - 1/15/10
• Survey 24 months - 7/15/10
• Survey 36 months - 7/15/11
• Survey 48 months - 7/15/12

25
Opportunities for Testing

• Thermal Vac Test
• TDRSS RF Compat. Testing
• MOC - ISOC I/F Test
• USN-MOC-ISOC I/F Test
• S/C Ops Procedures Test
• Suite of Regression Tests

26
End Here
27
ISOC Lab Space

• Computers with monitors keyboards
• MAESTRO workstation
• GSEOS Laptop - 2
• Data Processing Computer - 2
• Computers for other uses - 3
• STK license

• Additional Office equipment
• Conference Table to seat at least 8
• Desks/chairs for computers
• Filing Cabinets - 3
• Bookshelf Cabinet - 4
• Phone
• Conference Phone
• Projection Screen
• Projector
• Routers

• CPU only
• Primary Archive computer
• Secondary Archive computer

• Other
• Outlets on 3 walls
• Outlets under conference table
• Ethernet jacks on at least 2 walls
• One must be outside firewall

• Hardware
• Spacecraft Bus Sim (3'x2'x4')
• CEU Sim

• Need floorplan, diagram lab space, magnetic key
  lock, pics and floorplans

28
Backup
29
PIGMI Forward Modeling Results
Kappa Dist. Opher Model
Kappa Dist. Pogorelov Model
Maxwellian, Opher Model

• All-sky ENA flux maps for several models using a
  Hammer-Aitoff projection.

0.45 keV
1.1 keV
2.6 keV
30
PIGMI Forward Modeling Results

• ENA flux for 2.645 keV with ? 1.63 using Opher
  model.

31
PIGMI Forward Modeling Results

• S/N at the nose of the termination shock for IBEX
  Hi (green) and IBEX Lo (Black) using the Opher
  model for a 2 year mission.
• Dashed lines, maxwellian distribution
• solid lines, kappa1.6

32
Data Levels
33
Data Processing Flow
34
IBEX-Hi DE Acquisition

• A complete IBEX-Hi sweep (6 energy steps x 2
  spins/energy step x 60 spin-bins/spin) 720
  spin-bins
• Each cell in the above represents DE
  pre-harvesting storage for holding 0 or more DEs
  for each of the Energy-Spin-Bins.
• Payload Firmware (PLFW) will store as many DE
  into this DE acquisition pool as they are being
  acquired.
• The above takes three minutes to acquire at 4 rpm
  spin rate
• Current DE telemetry packing scheme can achieve
  approximately 720 DEs per IBEX-Hi sweep, so use
  720 as telemetry cap in this example

35
IBEX-Hi DE Harvesting
Examples of harvested events in first sweep

• Regions with low count rates are likely to be
  from the heliosphere (our key science)
• Principle Start with the valleys and work up to
  the mountains
• Starting from (Energy,Spin,Bin)(0,0,0), if a DE
  is available for that Energy-Spin-Bin, select one
  DE at random (or by using Priority Table and
  Random combination) in that Spin-Bin for
  downlink. That DE is removed from the DE
  acquisition pool.
• Traverse entire DE acquisition pool, select at
  most one DE per Energy-Spin-Bin cell for downlink
  using same choice scheme as above
• Traversal is performed by incrementing Spin-Bin
  the fastest, then Spin, then Energy
• The DE acquisition pool is traversed repeatedly
  until the cap of 720 telemetered DE events is
  achieved

36
A History of IBEX-Hi DE Culling Schemes(for
reference)

• Favors bins with least number of DE
• Send all the DE where there is only 1 DE per
  Energy-Spin-Bin
• If telemetry available, send all the DE where
  there are 2 DE per Energy-Spin-Bin
• If telemetry available, send all the DE where
  there are 3 DE per Energy-Spin-Bin
• Etc.
• (IBEX-Hi DE type, CEM D reading) priority table
• Present scheme Gives every bin a vote, but
  favors bins with less DE

37
Direct Event Types (IBEX-Hi)

• Pr - priority based on sims
• abc (ABC) pulses latched after short (long)
  window
• TtofC (abc ! ABC)
• ZtofC (c0)

38
IBEX-Hi DE List (compact scheme)

• DE list generated every energy sweep (12 spins)
• 800 direct events stored as list of timestamps
• There are 16 unique event types (combination of
  CEM short long pulses)
• Bit list for the 12 spins x 16 event types (192
  bits).
• When an event occurs a bit is flipped (1)
• List of 12 bit direct event time stamps in the
  following representative order
• spin 0, type ABC
• timestamp 0 (position 1)
• timestamp 1 (position 2)
• ...
• spin 0, type AB,
• timestamp 0 (position ..)
• timestamp 1
• ...
• ... (event types for spin 0)
• spin 2, type ABC
• timestamp 1
• ... (event types for spin 1)
• ... (event types for spin 2)

39
IBEX-Hi DE List (compact scheme)

• Hi DE List provides lack of redundant data
  (similar to gzip)
• Progression exceptions and spin/event-type table
  needed for unique decompression

40
Top Level Schedule

• Faux Telemetry Scheme - 4/20/07
• S/W Build 1 - June/07
• Toolbox functions defined
• Level 0.5 Science S/W
• Level 0.5 P/L Firmware
• Command Load Verification Defnt
• Command Load S/W Build
• Flight Rules Constraints
• Mag Model
• TS ENA Model
• Thermal test at SwRI - 7/15/07
• MOC I/F ISOC - 9/19-10/9/07
• Ground system I/F tests
• Mission PER - 10/24/07
• Grnd Netwrk Data Flow Test - 12/20/07
• Test MOC I/F ISOC - 12/20/07 - 1/4/08
• ISOC/MOC Command Prcess - 1/7-8/08
• S/W Build 2 (post-cal) - 1/7/08
• SCB Attitude Determination

• SWT - May/2008
• IBEX Ground Seg End-to-End - 5/23/08
• Rehearsals/tests - April-June/08
• S/W Build 4 (flight build) - 6/2/08
• Global Mapping S/W
• Aliveness test, CEU functional test, HiLo
  Functional test, Initial rampup
• Web I/F, SOH Database
• S/W Build 5 (in flight) - 10/15/08
• Model dependent corrections
• Flux calculations
• Partial Results - 12/8/08
• Survey 6 Months - 1/15/09
• First mapping publication - 1/22/09
• Survey 12 months - 7/15/09
• ISOC S/W Build 6 - 7/15/09
• Survey 18 months - 1/15/10
• Survey 24 months - 7/15/10
• Survey 36 months - 7/15/11
• Survey 48 months - 7/15/12

41
Payload OperationsCommand Load Validation

• Software constraint checks for
• Potentially hazardous commands
• HV turn-on
• Large commanded voltage jumps
• Operational constraints
• Sensors in standby below 10 RE
• Sensors off during HPS maneuvers
• Order of operations
• Garbled commands
• Human checks
• In addition to software checks, MOC and ISOC
  personnel will manually check command loads
  before uplink

42
ABS File

• An optional input file for Cyclic Redudancy
  Checks (CRC), containing manually created
  commands with absolute timestamps for spacecraft
  or payload maintenance
• Contains absolutely-timed spacecraft commands
  and/or general timeline elements
• Two formats available
• COMMANDS_ONLY is a format containing only
  spacecraft or payload commands
• Header lines
• Header lines
• FORMATCOMMANDS_ONLY
• BEGIN
• 2008/10/16T030000.000Zacstart_rts 51 some
  comment
• 2008/10/16T040000.000Zacnoop some comment
• END
• MIXED is a format containing both
  spacecraft/payload commands and other arbitrary
  event names that can trigger a rote expansion
• Header lines
• Header lines
• FORMATMIXED
• BEGIN

43
Science Tasking File (STF)

• An optional input file for CRC, generated by the
  ISOC, containing actual spacecraft commands (bus
  or payload) that the ISOC wishes to execute
  during the planning period
• Format is the same as the Absolute Command File
  (ABS)
• If STF contains only commands, it can be in the
  COMMANDS_ONLY ABS format
• If the ISOC wishes to coordinate with Orbital the
  placement of a meta-event onto the timeline in
  the STF with a command set, the MIXED ABS format
  can be used
• See samples in the ABS file description

44
IBEX-Hi DE Harvesting Comments (1/2)

• If this simple traversal scheme is used, i.e.,
• Starting at Energy,Spin,Bin (0,0,0)
• Traversing by Bin the fastest, then Spin, then
  Energy
• Then the beginning areas (near (0,0,0)) are
  favored for downlink
• Possible solution (which favors telemetering
  cells with the least DE)
• If, after one complete traversal there is
  telemetry available, select and telemeter those
  cells that have only one DE available until all
  those are exhausted or the telemetry cap is
  reached.
• If the telemetry cap is not reached, choose cells
  with only two DE available and select one of the
  DE for downlink. If downlink still available,
  telemeter the cells with one DE left.
• If the telemetry cap is not reached, choose cells
  with only three DE available and select one of
  the DE for downlink. Etc, etc.

45
IBEX-Hi DE Harvesting Comments (2/2)

• Another solution (which favors random selection)
• If, after one complete traversal there is
  telemetry available, then choose
  (Energy,Spin-Bin) cells at random and apply same
  selection scheme on chosen cell. Repeat until
  downlink cap is reached.
• Note that energy and spin pool dimensions could
  be collapsed together so that we essentially have
  6 Energy x 60 Spin-bins for 360 cells rather than
  720 cells. We could completely traverse the pool
  twice for this example telemetry cap value of
  720.
• Must come up with random algorithm. It could
  be seeded with the time or perhaps low-order
  bits of A/D readings.

46
Using the poles to do stuff

• One of the interesting things that came out of
  today's meeting was an idea Geoff hadto use the
  poles for special payload maintenance operations
  (see below). Since thepoles are so oversampled,
  if we can do these special operations for a
  portion ofeach spin (or every Nth spin) while
  looking at the poles rather than take a chunk
  oftime out of all look directions, it would be
  excellent. We could get the extrameasurements to
  characterize the data sensor performance as
  well as not takingviewtime away from the low
  sampling areas around the equatorial plane.We
  should brainstorm what we could use this for. The
  PLFW design is very flexible(thanks John!) and is
  currently possible to do each of the following
• Gain testing
• 1) Noise measurement (I think I'm using 'noise'
  correctly here, but I'm not sure)Turn ESA off
  when looking at poles (between bin X Y) for one
  energy step out ofeach energy sweep. The energy
  step replaced with this noise count can be
  cycledthrough for each energy sweep (0 ESA
  setting would replace step 1 for sweep 1, step2
  for sweep 2, etc...). Initially we had ruled this
  test out because it would cutinto statistics and
  the count rates would be so low that it would not
  give enoughmeaningful info to take the statistics
  hit. We should rethink this application withthis
  new 'pole viewing' approach. (The width of the
  sector for these operationswould also need to
  take into account voltage settling times... we
  are beingover-conservative in our nominal ops
  data processing - throwing out a bin at eachESA
  change.)
• 2) Pressure measurement Same concept as above,
  but instead of setting the ESA value to 0,
  stepping theelectron rejection voltage in front
  of the collimator down for that sector of thesky.
  This pressure measurement is stepping the e-
  rejection voltage down in a seriesof steps. We
  need to verify that stepping down
  non-sequentially (see V flow below)will give you
  the same results as stepping the e- rejection
  voltage sequentially. ie. (Vnominal (most of
  spin) -gt Vnominal - X (at pole) -gt Vnominal (most
  of spin) -gtVnominal -2X (at pole) -gt
  Vnominal(most of spin) -gt Vnominal -3X(at pole)
  ... ) Anyway, just wanted to make sure this
  discussion doesn't get lost in the fray.
• Chelle
  
• 1. That sounds similar to what we were going to
  do for IBEX-Lo anyway during theiroxygen mode,
  correct?
• 2. Shouldn't be too hard to DO. I think the
  ramifications on the data productswould need to
  be thought through though -that's really the hard
  part.

47
S/W Maintenance

• IDL needed
• GSEOS needed
• Maestro needed
• C-programs maintenance