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- Sandberg, Gustaf, 1982, et al.
(författare)
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Comparison of L- and P-band biomass retrievals based on backscatter from the BioSAR campaign
- 2009
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Ingår i: Proceedings of IGARSS 2009 Symposium, Earth Observation – Origins to Applications, Cape Town, South Africa, 13-17 July, 2009. - 9781424433957 ; IV, s. 169-172
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- With the continued threat of global warming, the need to obtain consistent and accurate measurements of the carbon stored in forests is strong. L- and P-band SAR backscatter data have shown to be sensitive to forest biomass, which in turn is coupled to the stored carbon. In this paper a biomass retrieval method is developed for L- and P-band using data from the BioSAR campaign conducted in Sweden during thespring 2007 over hemi-boreal forest. The results show that the use of L-band data gives an underestimation of biomass for stands with high biomass; while for P-band no such underestimation is seen. RMSEs are found to be 30-40% of the mean biomass for L-band and about 25% for P-band for stands with biomass ranging from 10 to 290 tons/ha.
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- Wyholt, Annelie, 1978, et al.
(författare)
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Evaluating VHF-Band SAR Autofocus Algorithms using a Forest Backscatter Model
- 2009
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Ingår i: 2009 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2009; Cape Town; South Africa; 12 July 2009 through 17 July 2009. - 9781424433957 ; 4, s. 9-12
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Konferensbidrag (refereegranskat)abstract
- The objective of this paper is to assess the accuracy of an autofocus method developed for the Fast Factorized Back-Projection (FFBP) algorithm in simulated scenarios. We specifically address the question whether correlation measurements between subimages will suffice in the focusing process in one arbitrary merging step. A forest clutter model is used together with a model of the impulse responses to simulate two SAR sub-images of a forest. Correlation is used for sub-image matching and residual displacement errors are compiled using simulation. We conclude that the matching error increases with increased number of trees per resolution cell but can be restored with a larger image size in the correlation measurements. We also conclude that the autofocus method will be successful.
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