Alessio Di SimoneTutor: Daniele Riccio

XXIX Cycle - I year presentation

Information extraction from a single SAR image

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My personal background• MSc in Telecommunications Engineering – Università di Napoli Federico II • Fellowship – MIUR – FSG research program "Sistemi di telecomunicazione innovativi a

larga banda anche con impiego di satelliti per utenze differenziate in materia di sicurezza, prevenzione e intervento in caso di catastrofi naturali”

Alessio Di Simone

DIETI

Electromagnetics Research Group

Remote Sensing Research Group

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Rationale: SAR images dependencies

Alessio Di Simone

SAR Image dependencies

Electromagnetic parameters Geometric parameters

Surface parameters • Dielectric constant (complex)

• Roughness• Topography (slopes)

Sensor parameters • Polarization• Operating frequency

• Look angle• Resolution

Known parameters

Unknown parameters

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Problem Statement: Well-posed?

𝐼=𝐼 (ε 𝑟 , σ ,𝐻 ,𝑇 , ϑ )

Alessio Di Simone

Ill-posedness

Cannot be removed (intrinsic property of the problem) Could be circumvented but…

Need for an adequate direct model

One equation, many unknowns

Objective Retrieving information from a single SAR image through mathematical and physical (electromagnetic) models

Interest Limited availability of resources, e.g., space missions, developing countries

: Relative permittivity: Electrical conductivity: Hurst coefficient: Topothesy: Local incidence angle

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(Fractal) Direct Model

Alessio Di Simone

Natural Surface Model (fBm)

Scattering Model (SPM)𝜎𝑚𝑛0 =2𝜋 8𝑘4𝑐𝑜𝑠4 𝜃|𝛽𝑚𝑛|

2 𝑆0

(2𝑘sin 𝜃 )2+2𝐻

Pr {𝑧 (𝑥 , 𝑦 )−𝑧 (𝑥 ′ , 𝑦 ′ )<𝜁 }= 1

√2𝜋 𝑇 (1−𝐻 )𝜏𝐻 ∫−∞

𝜁

exp(− 𝜁2

2𝑇 2 (1−𝐻)𝜏2𝐻 )𝑑𝜁

SAR Image Model

T: TopothesyH: Hurst coefficient

Backscattering coefficient: Propagation constant: Local incidence angle: Reflection coefficient: Spectral amplitude

: Calibration constant: Azimuth SAR resolution: Slant range resolution

𝐼=𝐺𝜎𝑚𝑛0

sin 𝜃𝛥𝑥 𝛥𝑟

𝐼=𝐺𝛥𝑥𝛥𝑟 2𝜋 8𝑘4𝑆0|𝛽𝑚𝑛|2 𝑐𝑜𝑠4 𝜃

(2𝑘 )2+2𝐻 (sin 𝜃 )3+ 2𝐻

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Sensitivity Analysis

Alessio Di Simone

SAR image greatest dependency is on the local incidence angle

Nor

mal

ized

SAR

Imag

e In

tens

ity

Dielectric constant Electrical conductivity [S/m]

Hurst coefficient Topothesy [m]

Incidence angle [degree]

Nor

mal

ized

SAR

Imag

e In

tens

ityN

orm

alize

d SA

R Im

age

Inte

nsity

Nor

mal

ized

SAR

Imag

e In

tens

ity

Incidence angle [degree]Incidence angle [degree]

Incidence angle [degree]

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Inversion Procedure

• Electromagnetic homogeneity of the surface, i.e., constant relative permettivity and electrical conductivity.

• Scale-invariant roughness, i.e., constant Hurst exponent and topothesy at any scale.

Alessio Di Simone

•Small slope regime, i.e., gentle topography.Only for simplifying the inversion procedure

Direct model linearization against local slopes• No dependency on azimuth slopes

Local slopes can be estimated

Hypotheses

Sub-hypothesis

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High-Level Products – I

• SAR Despeckling (Non Local Means Approach)

Alessio Di Simone

Original SAR image Despeckled image

No resolution degradation

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High-Level Products – II

• Local Incidence Angle Map • Digital Elevation Model

Alessio Di Simone

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Next years…• Research activities:

– Complete Model, rather than the linearized one.– Incidence angle estimation, rather than local slopes.– Further information retrieving.

• Training activities:

Alessio Di Simone

Credits year 1 Credits year 2 Credits year 3

1 2 3 4 5 6

Estimated

bimonth

bimonth

bimonth

bimonth

bimonth

bimonth

Summary Check

Estimated Check

Estimated Check Total

Modules 30 3 3 6 3 10 25 20-40 18 10-20 6 0-10 49

Seminars 8 1,2 0,9 0 1 1 0,9 5 5-10 8 5-10 5 0-10 18

Research 22 7 5 7 3 6 2 30 10-35 34 30-45 49 40-60 113

60 8,2 8,9 10 10 10 12,9 60 60 60 180

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List of publicationsJournals

1. Di Martino, G., Di Simone, A., Iodice, A., Riccio, D., “Shape from Shading and SAR Images,” IEEE Trans. Geosci. and Remote Sens.,

(resubmitted).

Conferences

2. Di Simone, A., Riccio, D., “A New Perspective in Shape from Shading from SAR Images”, IEEE Graduate of the Last Decade (GOLD)

Conference, Berlin, June, 5-6, 2014.

3. Di Martino, G., Di Simone, A., Iodice, A., Riccio, D., and Ruello, G., “On shape from Shading and SAR Images: an Overview and a New

Perspective,” International Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, July, 13-18, 2014.

4. Di Martino, G., Di Simone, A., Iodice, A., Riccio, D., and Ruello, G., “Polarimetry and Shape from Shading,” POLinSAR Conference,

Frascati, January, 26-30, 2015. (accepted)

5. Di Martino, G., Di Simone, A., Iodice, A., Riccio, D., and Ruello, G., “SAR Shape from Shading in Suburban Areas,” Joint Urban

Remote Sensing Event (JURSE), Lausanne, March, 30 – April 1, 2015. (accepted)

6. Di Martino, G., Di Simone, A., Iodice, A., Riccio, D., and Ruello, G., “Electromagnetic Model for SAR Shape from Shading,” RiNEm, pp.

277-280, Padova, September, 15-18, 2014.

Alessio Di Simone