[PPT] - Assimilative Modeling of Ionospheric Dynamics for Now-casting of HF PowerPoint Presentation

SLIDE 1

1

Assimilative Modeling of Ionospheric Dynamics for Now-casting of HF Propagation Channels in the Presence of TIDs

Dr. L. J. Nickisch, Dr. Sergey Fridman, Dr.

Mark Hausman, Dr. Shawn Kraut

NorthWest Research Associates, Monterey, California

Dr. George Zunich

Zunicalc, Inc., Monterey, California Presented at the 2015 Ionospheric Effects Symposium 12 May 2015

SLIDE 2

2

Background

IARPA HFGeo program seeks improvements in

ionospheric modeling and to mitigate the effects

f traveling ionospheric disturbances on

geolocating HF emitters

Our approach is to use the GPSII ionospheric

data assimilation model, assimilating information from known reference point (KRP) emitters in the region of interest

– Delay/Doppler/Angle-of-Arrival measurements of KRPs

Theory for delay-Doppler-AoA assimilation

presented in a companion paper (Fridman, et al., IES 2015)

Here we present results from the IARPA HFGeo

WSMR collection campaign of January 2014

AoA = Angle of Arrival

SLIDE 3

3 3

The Ionospheric Reconstruction Problem: Tikhonov Method

{ }

] [ Biases )}, , ( { ) , ( ) , (

) , (

U M Y t u U e t N t N

t u

≈ = = r r r

r

Y is the set of measured absolute/relative TEC values and data points from other types of ionospheric measurements.

The nonlinear optimization problem is solved iteratively (Newton-

Kontorovich).

1 ) dim( ]) [ ( ]) [ (

1

≤ − −

−

Y U M Y S U M Y

T

min

1

→

− U

P U T

The pseudo-covariance P matrix is defined in such a way that the

stabilizing functional tends to take on larger values for unreasonably behaving solutions (“reasonable”  “smooth”).

There are infinitely many such solutions: The smoothest solution is selected by minimizing the stabilizing functional The solution must fit the data within errors of measurements.

Error covariance matrix Pseudo-covariance matrix

SLIDE 4

4

Delay-Doppler Assimilation

Good results on TID

modeling can be attained by assimilating only delay-Doppler data

f receptions from

Known Reference Point (KRP) emitters

Links used in the

following results are shown here

G10 Green KAFB NSO Roswell R

b

P 6 1 6 F r a n P

n

d Q u e e n O s c u r a N 1 G r e e n R P 1 = Tx SITE (BLUE) = Rx SITE (RED) = LINK MIDPOINT (COLOR MATCHES LINK)

50 100 150 200 km 50

107.0° W 106.0° W 105.0° W 104.0° W 33.0° N 34.0° N 35.0° N RP1 to G10 RP1 to Green RP1 to KAFB RP1 to NSO Fran to G10 Green to G10 Rob to G10 ASSIMILATED LINKS

SLIDE 5

5

Results on an assimilated link

16:00 17:00 18:00 19:00 20:00 8 10 12 14 16 18 time (on Jan 19)

deg. North of Zenith

Degrees North of Zenith (Fran to G10): train O, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS) 16:00 17:00 18:00 19:00 20:00

5
4
3
2
1

1 time (on Jan 19)

deg. East of Zenith

Degrees East of Zenith (Fran to G10): train O, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS)

4
3
2
1

1 2 3 4

4
3
2
1

1 2 3 4 in-plane horizontal error (deg) in-plane vertical error (deg) In-plane Err. w.r.t. Array Est. 1 2 3 4 5 6 7 8 9 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 circular solid angle error (mSR) empirical CDF probability Solid Angle Error Emp. CDF With bias Bias removed

SLIDE 6

6

Results on a non-assimilated link

16:00 17:00 18:00 19:00 20:00 10 12 14 16 18 20 22 time (on Jan 19)

deg. North of Zenith

Degrees North of Zenith (N1 to G10): train O, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS) 16:00 17:00 18:00 19:00 20:00

3
2
1

1 2 3 time (on Jan 19)

deg. East of Zenith

Degrees East of Zenith (N1 to G10): train O, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS)

6 -5 -4 -3 -2 -1

1 2 3 4 5 6

6
5
4
3
2
1

1 2 3 4 5 6 in-plane horizontal error (deg) in-plane vertical error (deg) In-plane Err. w.r.t. Array Est. 1 2 3 4 5 6 7 8 9 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 circular solid angle error (mSR) empirical CDF probability Solid Angle Error Emp. CDF With bias Bias removed

SLIDE 7

7

Delay-Doppler-AoA Assimilation

Better results on

TID modeling can be attained by also assmilating Angle-

f-Arrival (AoA)

data in addition to delay-Doppler data

f receptions from

Known Reference Point (KRP) emitters

Links used in the

following results are shown here

Cherry G10 Green KAFB NSO Roswell Rob P616 Fran Pond Queen Oscura N1 Green RP1 = Tx SITE (BLUE) = Rx SITE (RED) = VERTICAL SOUNDER (MAGENTA) = LINK MIDPOINT (COLOR MATCHES LINK)

50 100 150 200 km 50

1 7 . 0° W 106.0° W 105.0° W 1 4 . 0° W 3 3 . 0° N 3 4 . 0° N 3 5 . 0° N RP1 to G10 Fran to G10 Green to G10 Cherry ASSIMILATED LINKS

SLIDE 8

8

Results on an assimilated link

16:00 17:00 18:00 19:00 20:00 10 12 14 16 18 20 22 time (on Jan 19)

deg. North of Zenith

Degrees North of Zenith (Green to G10): train O+VI, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS) 16:00 17:00 18:00 19:00 20:00

5
4
3
2
1

time (on Jan 19)

deg. East of Zenith

Degrees East of Zenith (Green to G10): train O+VI, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS)

3
2
1

1 2 3

3
2
1

1 2 3 in-plane horizontal error (deg) in-plane vertical error (deg) In-plane Err. w.r.t. Array Est. 1 2 3 4 5 6 7 8 9 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 circular solid angle error (mSR) empirical CDF probability Solid Angle Error Emp. CDF With bias Bias removed

SLIDE 9

9

Results on a non-assimilated link

16:00 17:00 18:00 19:00 20:00 8 10 12 14 16 18 20 time (on Jan 19)

deg. North of Zenith

Degrees North of Zenith (Pond to G10): train O+VI, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS) 16:00 17:00 18:00 19:00 20:00

4
3
2
1

1 time (on Jan 19)

deg. East of Zenith

Degrees East of Zenith (Pond to G10): train O+VI, trace O

Govt. (Clean,culled)

J-S Ray Trace (IS)

3
2
1

1 2 3

3
2
1

1 2 3 in-plane horizontal error (deg) in-plane vertical error (deg) In-plane Err. w.r.t. Array Est. 1 2 3 4 5 6 7 8 9 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 circular solid angle error (mSR) empirical CDF probability Solid Angle Error Emp. CDF With bias Bias removed

SLIDE 10

10

Ionogram comparison

3 4 5 6 7 8 9 MHz

SLIDE 11

11

Lessons

Notably, delay-Doppler assimilation of KRP data

is sufficient to define TIDs in the ionosphere model and track AoA deviations

Delay-Doppler-AoA assimilation of KRPs works a

1

Assimilative Modeling of Ionospheric Dynamics for Now-casting of HF Propagation Channels in the Presence of TIDs

Mark Hausman, Dr. Shawn Kraut

NorthWest Research Associates, Monterey, California

Zunicalc, Inc., Monterey, California Presented at the 2015 Ionospheric Effects Symposium 12 May 2015

2

Background

ionospheric modeling and to mitigate the effects

geolocating HF emitters

data assimilation model, assimilating information from known reference point (KRP) emitters in the region of interest

– Delay/Doppler/Angle-of-Arrival measurements of KRPs

presented in a companion paper (Fridman, et al., IES 2015)

WSMR collection campaign of January 2014

AoA = Angle of Arrival

3 3

The Ionospheric Reconstruction Problem: Tikhonov Method

{ }

] [ Biases )}, , ( { ) , ( ) , (

U M Y t u U e t N t N

≈ = = r r r

Y is the set of measured absolute/relative TEC values and data points from other types of ionospheric measurements.

Kontorovich).

1 ) dim( ]) [ ( ]) [ (

≤ − −

Y U M Y S U M Y

min

→

P U T

stabilizing functional tends to take on larger values for unreasonably behaving solutions (“reasonable”  “smooth”).

4

Delay-Doppler Assimilation

modeling can be attained by assimilating only delay-Doppler data

Known Reference Point (KRP) emitters

following results are shown here

5

Results on an assimilated link

6

Results on a non-assimilated link

7

Delay-Doppler-AoA Assimilation

TID modeling can be attained by also assmilating Angle-

data in addition to delay-Doppler data

Known Reference Point (KRP) emitters

following results are shown here

8

Results on an assimilated link

9

Results on a non-assimilated link

10

Ionogram comparison

11

Lessons

is sufficient to define TIDs in the ionosphere model and track AoA deviations

bit better (not surprisingly)