Design Team Preliminary Questions

1
Design Team Preliminary Questions

• Purpose
• To get a head start on the two week design
  process
• To get inputs from the experts that wont be able
  to make the two week period
• Structure of questions
• Organized by area of expertise
• Intent is to have the experts answer only
  questions relative to their field
• Answers should focus on how the systems would
  change depending upon the proposed architecture,
  e.g. Ground only, Space only Distributed or
  Central Observation or forecast

2
Ionospheric Questions(1)

• COSMIC
• How many COSMIC sensors needed?
• Fewer than currently planned?
• Would this number change with a GPS/OS or COSMIC
  complement?
• Direct downlink to the user or will go to a
  ground station?
• Multiplatform data required for product?
• Proposed data rates
• C/NOFS
• How many C/NOFS platforms needed?
• What is the sensor suite capability planned?
• Would we modify the sensor suite depending upon
  the architecture (space or space/ground)?
• Direct downlink to the user or will go to a
  ground station?
• Proposed data rates

• SCINDA
• How many SCINDA sites needed for a ground only
  architecture?
• How many SCINDA sites needed for mixed (space and
  ground) ?
• Best method to link to central and distributed
  user?
• proposed data rates
• GPS/OS
• How many sensors needed
• What is the best mix to complement SCINDA and or
  COSMIC for global coverage
• How Useful (relative to COSMIC)?
• Direct downlink? Best method to link to central
  and distributed user?
• proposed data rates
• Direct downlink?

3
Ionospheric Questions(2)

• UV Scintillation imagers
• How many sensors?
• Direct to users?
• Where would UA imagers best be used?
• Data rates?
• Topside sounders
• How useful?
• Direct downlink?
• Data rates?
• Bottom Side sounders
• How useful?
• Direct downlink?
• Data rates?
• JPL TEC Network
• Whats the best mix between this network and
  other ways to measure TEC?
• Are global measurements needs
• How many sites are needed?

• Ionospheric Models
• Existing - which current Ionospheric model should
  we use as a representative to show the complexity
  increase to the next generation?
• Ionospheric assimilation models?
• Will there be one model handling all aspects of
  the ionosphere, different classes?
• processed by center or user?
• Complexity of each
• Size (lines of code)
• Inputs, Outputs
• Maturity/Risk

4
Magnetosphere Questions

• Compact Particle Sensors
• What should the level of deployment (density)?
  Every satellite/DoD satellites only, some DoD
  satellites?
• Should a different level of deployment be used on
  type of architecture?
• What kind of capability should be added to CEASE?
  accelerometers, discharge imagers, etc?
• Probable size, weight , and power for each
  version?
• Complexity?
• Probable cost, including integration?
• Is there a reason to link to anyone other than
  the user?
• Proposed data rates

• Neutral Particle Imagers
• Best use?
• Number of sensors needed?
• Direct downlink to the user or will go to a
  ground station?
• Proposed data rates
• Are there any additional magnetospheric sensors
  we should include?

5
Solar Questions

• UV Imaging
• Need?
• What wavelengths are needed?
• Solar Imaging (H-alpha)
• Number of sensors needed for ground or space only
  imaging?
• Best complement for a space and ground
  architecture?
• Way to downlink to user?
• Data rates?
• SMEI
• Relative performance on a STEREO type platform
  vs. single observation platform at L1 or GEO
• Single observation performance vs. Coronographs
• Best platform sharing mix
• Which sensors should be packaged together on a
  single platform?
• Parasite on another platform?

• Coronographs
• What is the relative performance of space vs.
  ground coronographs
• Relative cost and performance of a L1 coronograph
  vs GEO vs LEO
• How many ground coronographs are needed?
• Data rates?
• Possible improvements by 2010?
• Best mix between Coronographs and a SMEI type
  sensor?
• X-Ray
• Best orbit and number of sensors to measure
  X-ray?
• Downlink? Can it go direct to user?
• Data rates?

6
Neutral Atmospheric Questions

• Beacons
• How useful?
• Accuracy related to GPS measurements or
  accelerometers

• Orbital parameters for satellite tracking
• Accuracy requirements for tracking
• On-board GPS position and attitude measurement
  accuracy needs
• Accelerometers, how many per platform
• Downlink to users?
• Data rates?
• Which is more accurate? On-board GPS or
  Accelerometers?
• What number of sensors are required to provide an
  adequate database?
• Radar tracking
• How useful?
• How does the performance of radar tracking
  compare to accelerometers or GPS on-board?

7
Model Questions(1)

• Coupled (Physics) models
• What part of the domains do they make sense for
• Are there general categories they can be
  separated into
• Particle environment
• Scintillation
• TEC/EDP
• Magnetic effects
• Neutral atmosphere
• Complexity of each
• Size (lines of code)
• Inputs, Outputs
• Maturity/Risk

8
Model Questions (2)

• Assimilation Models
• What part of the domains do they make sense for?
• Are there general categories they can be
  separated into
• Particle environment
• Scintillation
• TEC/EDP
• Magnetic effects
• Neutral atmosphere
• or
• Ionospheric/Magnetosphere/Solar wind/Neutral
  atmosphere
• Complexity of each
• Size (lines of code)
• Inputs, Outputs
• Maturity/Risk

9
Model Questions (3)

• How will these classes of models change if we had
  a
• Ground architecture only
• Space architecture only
• Which of set of these models will the user
  directly be able to run for the fully distributed
  architectures that have the data going directly
  to the user?

10
SCINDA

• Q How many SCINDA sites needed for a ground
  only architecture ?
• A Threshold number of sites needed will be 40
  in the equatorial region. The sites will be
  distributed in 20 segments equi-distributed in
  longitude. Each segment will consist of 2 sites,
  one near the magnetic equator and the other at
  about 15o magnetic latitude. When necessary,
  SCINDA needs to be deployed on ships.
• For coverage at high latitudes, 20 additional
  SCINDA sites will be needed. Fifteen sites will
  be distributed in longitude over the auroral oval
  and the remaining 5 sites needed to be
  distributed within the polar cap.
• Q How many SCINDA sites needed for mixed (space
  and ground) ?
• A In the equatorial region, with C/NOFS in
  space, threshold number of SCINDA sites will be
  20.
• In the polar region, with COSMIC in space
  performing scintillation measurements by GPSOS,
  the number of SCINDA sites will be reduced to 10.
• Q Best method to link to central and distributed
  user ?
• A In the equatorial region, two SCINDA segments
  (4 sites) to the east and the west of a user need
  to be connected to the user in that longitude
  sector. In addition, all SCINDA sites in the
  equatorial region need to be connected to a
  central site for mapping outages over the entire
  equatorial region.
• At high latitudes, each user needs to be
  connected to 4 SCINDA sites to the north and
  south and to the east and west.
• Q Proposed data rates ?
• A Very low 10 Kbytes per 15 minutes per SCINDA
  site.

11
GPSOS

• Q How many sensors needed ?
• A Two sensors to the fore and aft of the
  satellite.
• Q What is best mix of SCINDA and or COSMIC for
  global coverage ?
• A With poor equatorial coverage of COSMIC, the
  threshold number of SCINDA sites in the
  equatorial region will be 44, as in ground only
  architecture.
• With excellent high latitude coverage of COSMIC,
  the number of SCINDA sites can be reduced by a
  factor of 2 to a total of 10 at high latitudes
  SCINDA data will be used to calibrate and
  validate COSMIC GPSOS scintillation data.
• Q How Useful (relative to COSMIC) ?
• A The crucial COSMIC sensor is the GPSOS. It
  will provide electron density profiles of the
  ionosphere, ionospheric scintillation at L-band,
  pressure, temperature bending angle and
  refractivity profiles in the stratosphere and
  troposphere, and water vapor profiles in the
  troposphere
• Q Direct downlink? Best method to link to
  central and distributed user ?
• A No, not the occultation data. Except for a few
  in-track occultations, the bulk of COSMIC
  occultation data will pertain to locations
  several thousand kilometers away from the
  satellite.
• In addition to the two proposed high latitude
  Earth stations at Fairbanks and Kiruna in the
  northern hemisphere, there should be two
  additional earth stations in the southern
  hemisphere. This will allow each COSMIC satellite
  to dump data at one of four Earth stations once
  per 1/2 orbit every 50 minutes.
• A Payload Operations and Control Center (POCC)
  will receive the data from the Earth stations as
  well as GPS and beacon data from a global network
  of 20-30 ground based receiver sites on real
  time. The latter dataset will be used to compute
  precise COSMIC orbits and to eliminate errors due
  to GPS satellite and receiver biases.
• The POCC will be connected to the user and the
  MPT.
• Q Proposed data rates ?
• A Ionospheric data 7 kbytes/sec Atmospheric
  data 15 kbytes/sec

12
COSMIC

• Q How many COSMIC satellites needed ? Fewer
  than currently planned ?
• A No. With currently planned 8 satellites, 1163
  ionospheric occultations are obtained during a 6
  hour period globally. This corresponds to an
  average of 3-4 occultations over 30o lat x 30o
  long grid.
• Q Would this number change with GPS/OS or COSMIC
  complement ?
• A No. Other satellites would improve coverage.
  Number of satellites proposed for COSMIC is
  minimal.
• Q Direct downlink to the user or will go to a
  ground station ?
• A Will go to a central processing center.
• Q Multiplatform data required for product ?
• A COSMIC will have high vertical and low
  horizontal resolution for the product Data from
  other platforms, such as NPOESS, GOES, POES, with
  high horizontal resolution will be complimentary
  to COSMIC.
• Q Proposed data rates ?
• A 7 kbytes/sec for ionospheric data 15
  kbytes/sec for atmospheric data.

13
C/NOFS

• Q How many C/NOFS platforms needed ?
• A One satellite, at this point, at the correct
  orbit - 12 degree inclination, 650 km altitude.
• One C/NOFS platform in the equatorial region
  provides 90 minute refresh time of data from one
  longitude sector. The sensor suite will provide
  specification of scintillation structures and
  their zonal convection as well as will forecast
  scintillations with a lead time of 4 hours. As
  such, one C/NOFS platform in theequatorial region
  should be sufficient.
• Q What is the sensor suite planned ?
• A The sensor suite is
• Plasma Probe - ion and electron density and
  density fluctuations
• Ion Drift Meter - 3 components of plasma velocity
• UV Limb Scanner - Electron density profile or as
  much info about profile as possible
• Multi-frequency Beacon - TEC and scintillation
• Neutral Wind Sensor - 3 Components of Neutral
  winds
• Electric Field Probe - 3 components of electric
  field, complements ion drift meter with more
  sensitivity
• GPS receiver - line of sight TEC, electron
  density profile and scintillation
• Q Would we modify the sensor suite depending
  upon the the architecture (space or space/ground)
  ?
• A The sensor suite on C/NOFS remains unchanged.
  This is a minimum suite of instruments to meaure
  critical parameters controlling equatorial
  ionospheric structure and dynamics, especially
  equatorial spread F. However, for space/ground
  architecture, the number of SCINDA sites in the
  equatorial region can be reduced by a factor of
  two.
• Q Direct downlink to the user or will go to a
  ground station ?
• A Initial CONOPS is downlink to AFSCN then to
  55SWXS. Outage maps to warfighters via normal
  55SWXS comm or via Global Broadcast System.
  However, the radio beacon may be received at user
  terminals on command to obtain real time
  scintillation specification.

14
UV Scintillation Imagers

• Q How many sensors ?
• A 3 sensors on 3 geostationary satellites will
  be able to monitor electron density structures
  globally, especially in the equatorial region.
• Currently UV sensors are able to measure
  electron density structures at macroscales. For
  measuring electron density structures causing
  scintillations, the image pixels should be small
  enough for the detection of irregularity scales
  in the range of 1km -100 m. RD needed for direct
  scintillation measurements by UV sensors.
• However, the detection of macroscales, such as
  the feature of the equatorial anomaly, in the
  post-sunset period can be used to predict the
  presence of equatorial scintillations. This is
  because the zonal electric field in the
  post-sunset period destabilizes the ionosphere
  as well as develop the equatorial anomaly.
• Q Direct to users ?
• A No, to the Central Processing Centers and then
  to the users.
• Q Where would UV imagers best be used ?
• A In the equatorial region, where macroscale and
  mesoscale electron density structures co-exist at
  the time of nightime scintillations.
• Q Data rates ?
• A TBD.

15
Topside Bottomside Sounders

• TOPSIDE SOUNDERS
• Q How useful ?
• A Very useful. It provides the electron density
  profile of the topside ionosphere which is not
  given by any other ground or space based sensor.
  The scale height of the topside ionosphere is
  crucial for extending ionospheric models of
  electron density to the plasmasphere. This is
  needed for the calibration of ionospheric and
  plasmaspheric TEC obtained from GPS observations.
  The topside sounders along with the bottomside
  sounders will be able to calibrate altimeters.
• Q Direct downlink ?
• A No. The data needs to be acquired at Earth
  Terminals and processed at the Processing Center
  and disseminated to the users.
• Q Data rates ?
• A 1 kbyte per 15 minutes.
• BOTTOM-SIDE SOUNDERS
• Q How useful ?
• A Very useful It provides crucial data input to
  electron density models, HF propagation circuits
  and GPS TEC validation. The current digisonde
  network of 15 sites needs to be enlarged to 50
  sites in order to encompass the sparse coverage
  between 15 degrees north magnetic latitude and
  the southern pole.
• Q Direct downlink ?
• A Direct downlink to a few users all data
  should be sent to the Processing Center which
  will disseminate the processed data to the users.
• Q Data rates ?
• A 1 kbyte /15 minutes

16
JPL TEC Network

• Q Whats the best mix between this network and
  other ways to measure TEC ?
• A The TEC measurments by GPSOS on NPOESS, C/NOFS
  and COSMIC can be best mixed with JPL TEC network
  data. By combining groundbased and space based
  TEC measurements, it is possible to produce 2-d
  electron density maps by the tomographic
  technique. The dual frequency altimeter data may
  also be combined with the JPL TEC network data
  for calibration and validation.
• Q Are global measurements needed ?
• A Yes In view of gradients of TEC, it is
  necessary to expand the global JPL TEC network.
  These receivers may also upgraded to record
  scintillation data in addition to TEC. With the
  infrastructure of a global network already in
  place, such upgrades will be a very
  cost-effective way for obtaining global
  specification of of L-band scintillation.
• Q How many sites are needed ?
• A 50 additional JPL sites will provide adequate
  global coverage.

17
Ionospheric Models

• Q Existing - which current Ionospheric model
  should we use as a representative to show the
  complexity increase to the next generation ?
• A Any of the physics based models, such as, Time
  Dependent Ionospheric Model (TDIM), Fully
  Analytical Ionospheric Model (FAIM) or
  Thermosphere-Ionosphere Electrodynamics General
  Circulation Model (TIEGCM) can be used. The
  complexity increase to the next generation will
  be demonstrated by developing a physics based
  Coupled Ionospheric Scintillation Model (CISM)
  from any of the above electron density models.
  CISM may be developed by coupling a physics based
  electron density model with models of plasma
  turbulence and radio wave scattering theory. This
  will require the development of nested-grid, and
  adaptive grid approaches in order that density
  structures of various scales can be
  self-consistently included in global models.
  NOTE the current scintillation model is the Wide
  Band Scintillation Model (WBMOD) which is only a
  climate model and not a weather model of
  scintillation. CISM will be a weather model of
  scintillation and will remove the current
  shortfall.
• Ionospheric assimilation models ?
• Q Will there be one model handling all aspects
  of the ionosphere, different classes ?
• A There should be two models, namely, the
  Parameterized Real Time Ionospheric Specification
  Model, PRISM, and the fully physics-based model,
  TDIM. PRISM is an operational model and is
  currently assimilating a wide range of data,
  that include bottom-side sounder data, TEC data
  from JPL TEC network, in-situ plasma data and
  precipitating ion and electron fluxes from DMSP
  satellite. TDIM may be adapted to a nested-grid
  and adaptive grid model to be able to assimilate
  ionospheric data at different horizontal
  veritcal scales. It may also be coupled to
  magnetospheric models made to assimilate
  magnetospheric outputs.
• Q Processed by center or user ? A Need to be
  processed by center.
• Q Complexity of each ? A Complex but is done by
  the weather people.
• Q Size (lines of code) A TBD.
• Q Inputs, Outputs A All types of ionospheric
  data, TBD.
• Q Maturity/Risk A Conceptually mature/Low Risk