Ambiência (Oct 2006)

Estimating 3-Dimensional Structure of Tropical Forests from Radar Interferometry / Estimativa da Estrutura 3-Dimensional das Florestas Tropicais Através de Interferometria de Radar

  • Robert Treuhaft,
  • Bruce Chapman,
  • Luciano Dutra,
  • João Roberto dos Santos,
  • Fábio Gonçalves,
  • José Claudio Mura,
  • Paulo Maurício de Alencastro Graca,
  • Jason Drake

Journal volume & issue
Vol. 2, no. Especial 1
pp. 111 – 119


Read online

This paper describes the retrieval of 3-dimensional vegetation density profiles from interferometric synthetic aperture radar (InSAR) using physical models. InSAR’s sensitivity to vertical structure is generally regarded as less direct and more difficult to understand than that of lidar. But InSAR’s coverage is superior to that of lidar, suggesting InSAR is more promising as an important component of a global 3-dimensional forest monitoring technique. The goal of this paper is to introduce, simplify and demystify the use of simple physical models to understand InSAR. A general equation expressing the InSAR observation in terms of density is described heuristically, along with the approximations in its development. The information content of the equation leads to the estimation of density parameters. Preliminary results are shown from a multibaseline C-band (wavelength=0.056 m) vertical-polarization interferometer, realized with AirSAR flown at multiple altitudes over primary, secondary, and selectively logged tropical forests, as well as abandoned pastures at La Selva Biological Station in Costa Rica.