modelling the ionosphere over europe: investigation of nequick formulation

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odelling the Ionosphere over Europe nvestigation of NeQuick Formulatio Benoît Bidaine 1 - F.R.S.-FNRS - [email protected] Prof. René Warnant 1,2 - [email protected] 1 University of Liège (Unit of Geomatics), Belgium - www.geo.ulg.ac.be 2 Royal Meteorological Institute, Belgium - www.meteo.be November 18th, 2008 5th European Space Weather Week (Brussels, Belgium)

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Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation. Benoît Bidaine 1 - F.R.S.-FNRS - [email protected] Prof. René Warnant 1,2 - [email protected] 1 University of Liège (Unit of Geomatics), Belgium - www.geo.ulg.ac.be - PowerPoint PPT Presentation

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Page 1: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

Modelling the Ionosphere over Europe:Investigation of NeQuick Formulation

Benoît Bidaine1 - F.R.S.-FNRS - [email protected]. René Warnant1,2 - [email protected]

1University of Liège (Unit of Geomatics), Belgium - www.geo.ulg.ac.be2Royal Meteorological Institute, Belgium - www.meteo.be

November 18th, 20085th European Space Weather Week (Brussels, Belgium)

Page 2: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

TEC

Ionosphere

Total Electron Content CET

Page 3: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

algorithm NeQuick 1 2

TEC has to be modelled for single frequency receivers.

• GALILEO algorithm usingNeQuick model

First step: let’s investigate NeQuick profile formulation.

• Validate and improve

Page 4: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

1. Tools and MethodModelling and measuring the ionosphere

NeQuick 2 improvesTEC estimation over Europe.

Page 5: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

NeQuick 2 improvesTEC estimation over Europe.

1. Tools and Method

2. Yearly StatisticsGlobal scheme

Modelling and measuring the ionosphere

Page 6: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

NeQuick 2 improvesTEC estimation over Europe.

3. Influence of k UnificationMain modification in NeQuick 2

1. Tools and Method

2. Yearly StatisticsGlobal scheme

Modelling and measuring the ionosphere

Page 7: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

NeQuick 2 improvesTEC estimation over Europe.

3. Influence of k UnificationMain modification in NeQuick 2

1. Tools and Method

2. Yearly StatisticsGlobal scheme

Modelling and measuring the ionosphere

4. TEC SplittingDistinguishing bottomside and topside

Page 8: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

3. Influence of k Unification

1. Tools and Method

2. Yearly Statistics

4. TEC Splitting

Page 9: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

NeQuick is an empirical « profiler ».

• Output = Ne

TEC with integration

• Layer peaks= anchor points

monthly median maps

• NeQuick 2 (Nava et al., 2008)

topside modification

h [km]

Ne [e- m-3]

1. Tools and Method

Bottomside

Topside

ICTP / U Graz / COST 296 and before

Page 10: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

We investigate NeQuick formulationusing collocated data.

• Actual measurements instead of monthly median maps constrain by means of ionosonde data manually validated digisonde data

• Modelled vertical TEC vs GPS TEC collocated ionosonde and GPS receiver GIM levelling (Orus et al., 2007)

1TECu 16 cm error for L1

1. Tools and Method

Page 11: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

We focus on mid-latitudesand high solar activity.

• Year 2002 (HSA)

• Three European locations with (nearly) collocated digisonde and IGS/EUREF station

1. Tools and Method

Page 12: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

3. Influence of k Unification

1. Tools and Method

2. Yearly Statistics

4. TEC Splitting

Page 13: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

TEC modelling improveson a yearly basis.

2. Yearly Statistics

0

5

10

15

20

25

30

35

40

El Arenosillo/San Fernando Roquetes Dourbes

TEC

[TEC

u]

Measured NeQuick 1 NeQuick 2

• TEC underestimated on average(! potential bias in GPS TEC data !)

• Bigger (around 20%) underestimation with NeQuick 2

Yearly TEC mean

Page 14: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

TEC modelling improveson a yearly basis.

2. Yearly Statistics

Yearly relative TEC standard deviation

0%

5%

10%

15%

20%

25%

30%

El Arenosillo/San Fernando Roquetes Dourbes

TEC

[%]

NeQuick 1 NeQuick 2

• Lower (around 20%) standard deviation with NeQuick 2

Page 15: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

3. Influence of k Unification

1. Tools and Method

2. Yearly Statistics

4. TEC Splitting

Page 16: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The topside shape parameter k was unified in NeQuick 2.

3. Influence of k Unification

• k involved in height-dependent scale height

• NeQuick 1: 2 formulas for k (April to September and October to March)

different statistics for each period

• NeQuick 2: 1 formula based on topside soundings

Page 17: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The improvement comes mainly from the topside modification.

• October to March: lower (15%) standard deviation with NeQuick 2

More homogenous with other period

3. Influence of k Unification

-30%

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

El Arenosillo/San Fernando Roquetes Dourbes

Evol

ution

April to September October to March

Evolution of TEC standard deviation from NeQuick 1 to 2

Page 18: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

3. Influence of k Unification

1. Tools and Method

2. Yearly Statistics

4. TEC Splitting

Page 19: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The topside plays a major role.

• Integrate bottomside Ne profile from digisonde

bottomside TEC

• Subtract to GPS TEC topside TEC

4. TEC Splitting

0

5

10

15

20

25

30

35

40

El Arenosillo/San Fernando Dourbes

TEC

[TEC

u]

Bottomside Topside

• Big proportion of TEC within topside (3/4, 1/4)

Page 20: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The improvement comes mainly from the topside modification.

• Bias/standard deviation evolution for topside between NeQuick versions corresponding to global statistics

4. TEC Splitting

Yearly topside TEC standard deviation

0

1

2

3

4

5

6

7

8

9

El Arenosillo/San Fernando Dourbes

TEC

[TEC

u]

NeQuick 1 NeQuick 2

Page 21: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

NeQuick 2 improves TEC estimation over Europe.

• Benefit from collocated data

• TEC statistics: standard deviation decrease by 20% to reach less than 20% with NeQuick 2 (mid-latitudes stations, high SA)

• Homogenisation thanks to topside modification

• Major role of topside

Page 22: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

TEC has to be modelled for single frequency receivers.

• Comparison of different GPS TEC data sets

• Ingestion: use of effective parameters to adapt NeQuick TEC to GPS TEC

• GALILEO Single Frequency Ionospheric Correction Algorithm

Page 23: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

Ionosphere

Page 24: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

Modelling the Ionosphere over Europe:Investigation of NeQuick Formulation

Benoît Bidaine1 - F.R.S.-FNRS - [email protected]. René Warnant1,2 - [email protected]

1University of Liège (Unit of Geomatics), Belgium - www.geo.ulg.ac.be2Royal Meteorological Institute, Belgium - www.meteo.be

November 18th, 20085th European Space Weather Week (Brussels, Belgium)

Page 25: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

We investigate NeQuick formulationusing collocated data.

foF2 yearly difference after validation

0

0,5

1

1,5

2

2,5

El Arenosillo Roquetes Dourbes

Station

foF

2 95

% le

vel [

MH

z]

a

1. Tools and Method

Page 26: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

We investigate NeQuick formulationusing collocated data.

1. Tools and Method

sTEC differences averaged by arc (Brussels – 2002)

Page 27: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

We investigate NeQuick formulationusing collocated data.

1. Tools and Method

Elevation filter (Brussels – March 28th, 2002)

Page 28: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

We investigate NeQuick formulationusing collocated data.

1. Tools and Method

Impact of elevation filter thanks to NeQuick simulations (Brussels – March 28th, 2002)

Page 29: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The topside shape parameter k was unified in NeQuick 2.

3. Influence of k Unification

Monthly TEC mean (Roquetes - 2002)

Page 30: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The topside shape parameter k was unified in NeQuick 2.

3. Influence of k Unification

Monthly TEC standard deviation (Roquetes - 2002)

Page 31: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The improvement comes mainly from the topside modification.

3. Influence of k Unification

Daily TEC profile (El Arenosillo - February 12th, 2002)

Page 32: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

The improvement comes mainly from the topside modification.

3. Influence of k Unification

Ne profile (El Arenosillo - February 12th, 2002 – 10 UT)

Page 33: Modelling the Ionosphere over Europe: Investigation of NeQuick Formulation

TEC has to be modelledfor single frequency receivers.

• PhD thesis at ULg – Unit of Geomatics sponsored by FNRS

• Collaborations- RMI (Brussels)- ESA/ESTEC (Noordwijk)- ICTP (Trieste, Italy)- Others to come…

After coffee break

+ posters