evaluation of space-based observation capabilities in oscar in support of gap analysis 12th european...

Evaluation of space-based observation capabilities in OSCAR

in support of Gap Analysis

12th European Space Weather Week,Ostend, 23-27 November 2015

Jérôme Lafeuille (WMO)

WMO; Name of Department (ND)

ESWW-12, Ostend, November 2015 2

Acknowledgements

Biz. Bizzarri analysed 900 instruments and developed 1800 rules !

Nils Hettich, Edward Akerboom, Timo Proescholdt developed the OSCAR software

Alain Hilgers and several of his ESTEC colleagues provided guidance on rules and properties for space weather sensors


Outline

1. Motivation2. OSCAR operational version3. New features (Version currently in test)4. Application of the expert system to space weather

sensors5. Perspectives


Motivation WMO Congress agreed to support space weather operational activities

(May 2015). This requires a comprehensive, global observing system, with global data sharing and cooperation

There are hundreds of space-based sensors but who knows which sensors are actually available or planned ? Which ones are relevant for “my” applications ?

A synoptic view of current and future capabilities is needed toperform a Gap Analysis and tosupport global planning and evolveto a true global observing “system”

WMO thus developed OSCAR“Observing System CapabilityAnalysis and Review” database


OSCAR/Space operational version (www.wmo.int/oscar)

• >900 instrument models• ~ 1000 visits/day• Worldwide users : space agencies, main operational centres,

application development centres, consultants, researchers, students…• Used for reports, application planning, gap analysis, socio-economic

benefit studies, frequency management, etc. in Earth Observation. • The Space weather part is not validated.

http://www.wmo.int/oscar

Factual information content Name, purpose Mass, power Orbit (type, alt, ECT, lon) Launch date, end date, status Data access, telecom frequencies


Satellite

Programme

Agency

Instrument • Name, purpose• Mass, power• Type, description, scan mode• Resolution FOV, coverage• Status• Spectral & other characteristics

Satellite payload• Detailed status, dates• Link to calibration• Link to event log

ESWW-12, Ostend, November 20157


Mapping instruments to variables

Basis of the gap analysis

Which instruments can measure a given variable?

Which variables can be measured with a given instrument?

Two sides of the same question


Measurement Timeline for Solar EUV flux

10

Outline





Instruments searchable by properties New !


Instruments searchable by properties


Instruments searchable by properties New !


New instrument-variable mapping

Two independent approaches will be available in OSCAR:

A simplified (trivial) approach :- for each sensor we record the «Mission objectives» stated by the instrument provider (measurements that the sensor has been specified to measure): primary, secondary, and opportunity objectives

An expert system based on physics-based objective rules- concept presented initially at ESWW-11 - implemented in the new version of OSCAR (currently in test)- validated for Earth Observation instruments only

New instrument-variable mapping principle

Instrument design requirements e.g: Energy bands Spectral

channels Aperture Resolution Dynamics No of channels Polarization Etc..


XXX

X

X

XXXX

X

X

XX

XXX

Variable 3

Variable x

17

Variable 2

Variable 4

Variable y

Variable 1

XXX

X

X

XXXX

X

X

XX

XXX

Science-based rules

Objective assessment

Algorithm summary


Type 1Type 2

Each instrument type has a set of properties which define a particular metrics

Instrument has a profile P in this metrics __________

Variable U

Variable V

Variable W

For a given variable we look at all rules applying to this variable and test the applicable instruments against these rules

For an instrument, the rule providing the best score defines the relevance of this instrument for the considered variable.

RuleRule

RuleRule

Enables objective comparison of potential performance of different classes of sensors Performance drivers are defined objectively on the basis of

physical measuring principles Each instrument is characterized by fully objective features

«Rules» are purely declarative – can be updated independently of the software itself - facilitating scientific maintenance

Transparent: the rules can be submitted to external reviews

Proved very efficient for the 600+ Earth Observation instruments (~ 1800 Rules for 120 variables)


Benefit of this expert system approach

Outline




Applying this approach to space weather sensors

• Step 1: Define an instrument typology • Step 2: For each type of sensor, identify the «properties», i.e.

the key specifications driving the performance • Step 3: For each variable, develop rules quantifying the

potential relevance of a sensor to measure a variable, as a function of the properties

• Step 4: Enter the applicable properties of each actual sensor


Work in progress !

Step1: space weather sensor typology


Solar activity monitors• Solar or space imager (incl. heliospheric imagers and coronograph)• Solar magnetograph (imaging spectrometer) and velocity sensor• Solar photometer or spectrometer • Solar microwave radiometer or radio receiver• Other solar monitorsSolar wind and interplanetary monitors• Solar wind radiometer/spectrometer • Solar wind particle spectrometer• Interplanetary magnetometer • Electric field/radio/other sensors(Charge det., dosimeter, plasma density probe)Geospace monitors • Geospace radiometer/spectrometer • Magnetospheric particle spectrometer• Magnetometer • Geospace electric field/radio/other sensors (Charge det., dosimeter, plasma drift) • Aurora or special imager (including plasmasphere UV)

Step 2: Properties for several sensor types (examples)


Solar imagers Particle spectrometers Magnetometers/Electric field sensor

Includes 17.3 nm Energy min for electron flux (keV) 3-axis magnetometer

Includes 19.3-19.5 nm Energy max for electron flux (keV) Uncertainty (nT)

Includes 28.4 nm Energy min for proton flux (keV) Resolution (nT)

Includes He-II Ly-α (30.4 nm) Energy max for proton flux (keV) Response frequency (Hz)

Includes Far UV (117-170 nm) Angular range (solid angle) in sr Measures electric field

Includes H Ly-α (121.65 nm) Angular resolution (% of 2π sr) Uncertainty (mV/m)

Includes CaII K (393.4 nm) Time resolution (s) (sampling rate) Dynamic range

Acquires White light Dynamics Is a charge detector

Has polarimetric capability Sensitivity Is a dosimeter

Has Doppler capability Is Pointing to the Sun Is a plasma drift meter

Is a Spectrometer Energy spectral resolution Is a plasma density probeIs a coronagraph Detects Electrons, protons

FoV inner/outer limit (SolarRadii) Detects alfa, heavy ions

Spatial resolution (km or arcsec) Detects neutrons

Step 3: Examples of rulesFor this Variable

With this type of instrument

If the following conditions are true Then the relevance is

Solar wind density

Particle spectrometer

Detects protons, 0-10 keVSun pointing ; Solid angle >= 2πEnergy spectral resol < 10% (resp. 20 %)Time resol < 10sDynamics 1:100,000; Sensitivity (TBD)

Excellent(resp. Very high)

Solar wind density

Particle spectrometer

Detects electrons, 0-100 eVSolid angle >= 2πEnergy spectral resol < 10% (resp. 20 %)Time resol < 10sDynamics 1:100,000; Sensitivity (TBD)

Excellent(resp. Very high)

Solar X-ray flux

Solar photometer/ spectrometer

X-Ray detector; include [0.05-0.8 nm] rangeFoV includes whole Sun; Time resol < 1 min

Excellent


Step 4: Populating the Instrument properties

• Information gathered for OSCAR -1 needs to be converted into the «Properties» framework

• Much of the required information is missing for space weather sensors

• Input from space agencies /instrument developers is dramatically needed



Example of Gap Analysis (on incomplete test data set)

Variable selected: Proton differential

directional flux

Method selected« Simplified » Gap Analysis

Outline




Discussion

• Experience with OSCAR for Earth Observation sensors suggests that OSCAR can be very useful for the SW community– Promote awareness /informed use of space-based sensors – Supports overall planning and gap analysis

• The expert system approach can become a collaborative tool– The «Rules» and properties can be reviewed by expert groups– Thus improving the evaluation, building confidence, shared ownership– Can contribute to capacity building

• Dependent on support from instrument providing agencies– Support dramatically needed to share detailed sensor characteristics

• Collaboration is welcome to the development of rules and for betatesting


Thank you for your attention!Please visit: www.wmo.int/oscar

Your feedback is welcome

www.wmo.int

evaluation of space-based observation capabilities in oscar in support of gap analysis 12th european...

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