![Comparison of Mapping Techniques Exa mple: Frame 1350 – North Slope, AK F. Meyer et al. IGARSS’11, Vancouver TEC from Dispersion Analysis [TECU] [TECU] Comparison of Techniques TEC from FR](https://image.slidesharecdn.com/contrib-of-desdyni-ionospheric-research-110728143308-phpapp02/85/contrib_of_DESDYNI_ionospheric_research-ppt-7-320.jpg)
![SAR Observations: SAR Swath acquired over Alaska imaged structure of Auroral Oval A Variation of more than 7 TECU over a distance of 750km was observed Significance: Support the analysis of structure, width, location of auroral oval Fairbanks, Alaska Example: Aurora Enhancement Signals from L-band SAR ~ 750 kilometers TEC [TECU]](https://image.slidesharecdn.com/contrib-of-desdyni-ionospheric-research-110728143308-phpapp02/85/contrib_of_DESDYNI_ionospheric_research-ppt-11-320.jpg)
![Open Three Year PhD Position starting fall 2011 / spring 2012 for a radar remote sensing research project at the Geophysical Institute of the University of Alaska Fairbanks on Theoretical Investigations into the Impact and Mitigation of Ionospheric Effects on Low-Frequency SAR and InSAR Data Research Focus: Investigation of spatial and temporal properties of ionospheric effects in SAR data Development of statistical signal models Design of optimized methods for ionospheric correction More information: Dr. Franz Meyer ( [email_address] ) and at: www.insar.alaska.edu](https://image.slidesharecdn.com/contrib-of-desdyni-ionospheric-research-110728143308-phpapp02/85/contrib_of_DESDYNI_ionospheric_research-ppt-19-320.jpg)
contrib_of_DESDYNI_ionospheric_research.ppt
- 1. F.J Meyer 1) 2) , J. Kim 3) , R. Brcic 4) , X. Pi 5) , A. Freeman 5) , M. Shimada 6) 1) Earth & Planetary Remote Sensing, University of Alaska Fairbanks 2) Alaska Satellite Facility (ASF) 3) Microwaves and Radar Institute, German Aerospace Center (DLR) 4) Remote Sensing Technology Institute, German Aerospace Center (DLR) 5) Jet Propulsion Laboratory (JPL) 6) Japanese Aerospace Exploration Agency (JAXA) Potential Contributions of the DESDynI Mission to Ionospheric Research Collaborating Organizations:
- 2. Outline Introduction Methods for Ionospheric Mapping from SAR Summary of Advantages of Space Weather Analysis using SAR Examples of Application to Observing Ionospheric Phenomena Conclusions
- 3. Methods for Ionospheric Mapping from SAR Ionosphere causes range of effects that can be used for ionospheric mapping Ionosphere (TEC) Faraday Rotation Azimuth Shift Range Shift Interferometric phase (differential) Dispersion
- 4. Methods for Ionospheric Mapping from SAR Faraday Rotation (FR) The longer wave length observation, the stronger ionospheric effects. FR is essential parameter to correct polarimetric distortions FR is a key element to mapping ionospheric effects from SAR data. Ionosphere (TEC) Faraday Rotation Azimuth Shift Range Shift Interferometric phase (differential) Dispersion
- 5. Methods for Ionospheric Mapping from SAR Faraday Rotation (FR) - Example Alaska Inland ( ref = 2.27°, hilly topography) Scattering Matrix-based Bickel & Bates Freeman 1 st Chen & Quegan Qi & Jin Freeman 2 nd Covariance Matrix-based
- 6. Methods for Ionospheric Mapping from SAR Dispersion Ionospheric delay varies across the bandwidth of a SAR signal. Signal Delay defined by signal frequency and ionospheric TEC Estimation of TEC from phase shifts between sub-bands Products: Ionospheric correction & TEC maps Ionosphere (TEC) Faraday Rotation Azimuth Shift Range Shift Interferometric phase (differential) Dispersion
- 7. Comparison of Mapping Techniques Exa mple: Frame 1350 – North Slope, AK F. Meyer et al. IGARSS’11, Vancouver TEC from Dispersion Analysis [TECU] [TECU] Comparison of Techniques TEC from FR
- 8. Optimizing Mapping Performance VU > Autor Name TEC dTEC/dx TEC TEC dTEC/dx dTEC/dx Method 1 Method 2 Method 3 Method 5 Method 6 Method 7 1 2 3 TEC TEC TEC 1 2 3 TEC TEC TEC 5 6 7 ∫ ∫ ∫ TEC
- 9. The Appeal of Ionospheric Mapping from SAR L-band SARs sensitive to ionospheric signals Faraday rotation-based Mapping: About 1 TECU in auroral and polar zones Low accuracy near equator Phase-based mapping: About 0.015 TECU (@: B=80MHz; =0.7; 1km×1km spatial averaging) Selling point “ Spatial Resolution and Coverage ”: Kilometer-scale resolution mapping of 2-D spatial variations in ionospheric TEC Selling point “ Temporal Resolution ”: Global mapping every ~6-8 days ~ 1 day repeat intervals in the auroral and polar zones Selling point “ Achievable accuracies ”:
- 10. Mapping Auroral Scintillation Signals with L-band SAR Scintillation Statistics Auroral Zone (Fairbanks, AK) Scintillation statistics obtained by processing GPS data acquired in 2000 Dawn Dusk DESDynI Dawn Dusk DESDynI
- 11. SAR Observations: SAR Swath acquired over Alaska imaged structure of Auroral Oval A Variation of more than 7 TECU over a distance of 750km was observed Significance: Support the analysis of structure, width, location of auroral oval Fairbanks, Alaska Example: Aurora Enhancement Signals from L-band SAR ~ 750 kilometers TEC [TECU]
- 12. Mapping Aurora Enhancements using SAR Pi, X., A. Freeman, B. Chapman, P. Rosen, and Z. Li (2011), Imaging ionospheric inhomogeneities using spaceborne synthetic aperture radar, Journal of Geophysical Research , 116 (A4), A04303. Aurora arcs approximately aligned with local magnetic inclination angle Turbulence Measurements from GPS
- 13. Dawn Dusk DESDynI Mapping Equatorial Scintillation Signals with L-band SAR Scintillation Statistics Equatorial Area Scintillation statistics obtained by processing GPS data acquired in 2000 Dawn Dusk DESDynI
- 14. Mapping Equatorial Scintillation Patterns Rainforest, Brazil Equatorial scintillation patterns in SAR data acquired at local evening (10pm) South-East Asia Source: M. Shimada, JAXA
- 15. Spatio-temporal Distribution of Observed Scintillation Patterns Total number of appearance : 1490: June 2006 ~ Dec. 2009 June, 2006~Dec.2006: 217 Jan. 2007~Dec.2007: 528 Jan. 2008~Dec. 2008: 469 Jan. 2009~Dec. 2009: 276 June.2006~Dec.2009: 1490
- 16. Spatio-temporal Distribution of Observed Scintillation Patterns Number of Scintillation signals in PALSAR data Sun Spot Number SAR data may support the study of frequency and extent of scintillation signals as a function of several driving forces F. Meyer et al. IGARSS’11, Vancouver Source: M. Shimada, JAXA
- 17. Plasma Depletions observed by SAR GPS shows depletion and turbulence at SAR acquisition time Analyzing Ionospheric Plasma Depletions Pi, X., et al. (2011), Journal of Geophysical Research , 116 (A4), A04303.
- 18. DESDynI is sensitive to ionospheric parameters Methods for high-resolution ionospheric mapping from DESDynI-like data are available Ionospheric maps from SAR show unprecedented spatial resolution The benefit of SAR for ionospheric research has been proven in various pilot studies In addition to maps, SAR can produce a wide range of statistical ionospheric parameters Combination with TandDEM-L opens additional opportunities Conclusions:
- 19. Open Three Year PhD Position starting fall 2011 / spring 2012 for a radar remote sensing research project at the Geophysical Institute of the University of Alaska Fairbanks on Theoretical Investigations into the Impact and Mitigation of Ionospheric Effects on Low-Frequency SAR and InSAR Data Research Focus: Investigation of spatial and temporal properties of ionospheric effects in SAR data Development of statistical signal models Design of optimized methods for ionospheric correction More information: Dr. Franz Meyer ( [email_address] ) and at: www.insar.alaska.edu
- 20. DESDynI and TanDEM-L – A System for Mapping Scintillation Drift? Several seconds of time separation between acquisitions -> interferometric phase sensitive to drift of scintillation patterns Example: Pursuit-mode TanDEM-X data; Time separation of acquisitions: 3 sec. – Signatures likely due to scintillation pattern drift