Forest 3-D characterization using SAR tomography: techniques and applications

Updated: 4 months ago
Deadline: 06 Apr 2017

Forest 3-D characterization using SAR tomography:  techniques and applications


https://www.ietr.fr/IMG/pdf/sujet_these/PhD_CNES_Forest_SAR_tomography_en.pdf


SAR tomography is a coherent imaging technique from which may be derived 3-D maps of the electromagnetic (EM) reflectivity of complex environments, and which revealed particularly well adapted to forest characterization (to estimate height, density, underlying ground topography, biomass). It will be implemented for the first time in a spaceborne radar context, in the frame of ESA's   Earth Explorer mission BIOMASS, to be launched in 2020. In particular, studies conducted  at CESBIO showed that robust biomass  estimators could be derived using P band data, over tropical forests in French Guyana. An analysis jointly led by IETR and CNES further refined this approach and established an analytical relationship using a simplified structural model.


The work to be carried out during this Ph.D.  study concerns three major axes of investigation : 

- Evaluation of the generalization of results obtained  in French Guyana to acquisition performed in Gabon during the  AFRISAR campaign in 2015 : pre-processing and 3-D focusing of airborne SAR data with precise topographic compensation, space-polarization decomposition, estimation,  simulation of spaceborne BIOMASS data 

- Estimation of realistic structural features of a forest cover : development of advanced tomographic SAR techniques (adaptive parametric approaches, using simple EM models of a vertically structures medium), adaptive sparse parametric estimation adapted to data acquired with polarization diversity.

- Preparation of the future BIOMASS mission through the study of the temporal evolution of tropical forest scattering patterns: influence of meteorological conditions during the data acquisition cycle (rain, wind) as well as evaluation of the potential of synergy with other types of data, such as LiDAR acquisitions or L band data that may become available through a tandem spaceborne mission.

This work will be performed in cooperation with different research institutes involved in the preparation of the BIOMASS mission : CESBIO, IRSTEA, Politecnico di Milano, EDB, ONERA.

REFERENCES

- D. Ho Tong Minh, T. L. Toan, F. Rocca, S. Tebaldini, M. M. d'Alessandro, L. Villard, "Relating P-Band Synthetic Aperture Radar Tomography to Tropical Forest Biomass," in IEEE TGRS, 52(2), Feb. 2014.

- B. El Hajj Chehade, L. Ferro-Famil, H. T. M. Dinh, T. Le Toan and S. Tebaldini, "Tropical forest biomass retrieval using P-band PolTomSAR data," EUSAR 2016,   Hamburg, Germany, 2016

- M. Neumann, L. Ferro-Famil, A. Reigber, "Estimation of Forest Structure, Ground, and Canopy Layer Characteristics From Multibaseline Polarimetric Interferometric SAR Data," in IEEE TGRS, 48(3), March 2010.

- D. Ho Tong Minh, S. Tebaldini, F. Rocca and T. Le Toan, "The Impact of Temporal Decorrelation on BIOMASS Tomography of Tropical Forests," in IEEE GRSL, 12(6), June 2015.

- S. Tebaldini, F. Rocca, M. Mariotti d'Alessandro and L. Ferro-Famil, "Phase Calibration of Airborne Tomographic SAR Data via Phase Center Double Localization," in IEEE TGRS 54(3), March 2016.


Organization (start Sept./Oct. 2017, duration  3 years)

 - Host institution : IETR (University of Rennes 1, France) 

 - Supervision:  Laurent FERRO-FAMIL (IETR) (Dir), Dinh HO TONG MINH (IRSTEA), Thierry KOLECK (CNES)


Candidate profile :

 - M.Sc. in Elec. Eng., Remote Sensing, Signal and Information Processing, Telecommunications... 

 - Basic knowledge in at least 2 of the following fields : radar, remote sensing, signal and information processing, wave propagation.


How to apply : APPLICATION DEADLINE March 29th 2017

Send  a CV, official M.Sc. grade transcripts and at least one letter of recommendation to  laurent.ferro-famil@univ-rennes1.fr, dinh.ho-tong-minh@irstea.fr, thierry.koleck@cnes.fr 


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