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A Refined Polarization Response, and Object Detection with Radar Polarimetry Using Dual-Frequency and Dual Aspect Angle Observations Teemu Tares and Martti Hallikainen Laboratory of Space Technology, Helsinki University of Technology Espoo, FINLAND. Electric Field Equation.
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A Refined Polarization Response, andObject Detection with Radar Polarimetry UsingDual-Frequency and Dual Aspect Angle ObservationsTeemu Tares and Martti HallikainenLaboratory of Space Technology, Helsinki University of TechnologyEspoo, FINLAND
Electric Field Equation Backscattered field as a function of incident field Jones vectors of incident and backscattered waves Sinclair matrix S describing the scatterer
Electric Field Ratio R = Polarization
Polarization Equation Scattered polarization as a function of transmit polarization
Power Equation Scattered power as a function of transmit polarization
Polarization Match Similarity of polarization states R1 and R2 1 = same polarizations 0 = orthogonal polarizations
Vertical cylinder Max. Power Min. Power V LCP RCP H
Horizontal cylinder Max. Power Min. Power V LCP RCP H
R-Helix Max. Power Min. Power V LCP RCP H
L-Helix Max. Power Min. Power V LCP RCP H
V Max. Power H LCP RCP Min. Power Power responses appear similarly • Vertical/horizontal • cylinder • Right-/left-handed • helix
Random Random type of scatterer Max. Power Min. Power V LCP RCP
Polarization Response • Power depends on: • Cos (R, Rmax) • Max. backscatter Pmax • Min. backscatter Pmin
Polarization Response • Power depends on: • Min. backscatter Pmin • Max. backscatter Pmax • Pol. match to Rmax • Power Eq. optimization: • Max. pol. (Pmax, Rmax) • Min. pol. (Pmin, Rmin) • Rmin orthogonal to Rmax
Maxxpower, minpower, maxpol match to H, HIS PCA MaxPower (4th root) MinPower (4th root) IHS = PC2(max,min) PC1(max,min) PC2(max,etah) MaxPol. H-Match
Building Detection Airphoto
+-45 Two linear polarizations: +45 (red) and –45 (green)
R/LCP Circular polarizations: RCP (red) and LCP (green)
HHVV Two linear polarizations: HH (red) and VV (green)
H vs. V Two linear polarizations: H (red) and V (green)
Maxpol Maximum power and polarization Intensity=Power Red = H Cyan = V E-SAR (L) Kirkkonummi 31.8.2000
Best Single-Channel Detection Result (H pol.) Green = detected Red = non-detected Blue = false alarm
Building detection False detection (%) Total Power H Transmit V Transmit HH VV HV Max. Power Buildings detected (%)
Conclusion • According to our studies … • Polarization response can be simplified. • Detecting buildings, H is best and HV not a good channel. • Polarimetric channels are more correlated than • frequency channels and aspect channels, especially.