Reviewing ALOS PALSAR Backscatter Observations for Stem Volume Retrieval in Swedish Forest
Journal article, 2015

Between 2006 and 2011, the Advanced Land Observing Satellite (ALOS) Phased Array L-type Synthetic Aperture Radar (PALSAR) instrument acquired multi-temporal datasets under several environmental conditions and multiple configurations of look angle and polarization. The extensive archive of SAR backscatter observations over the forest test sites of Krycklan (boreal) and Remningstorp (hemi-boreal), Sweden, was used to assess the retrieval of stem volume at stand level. The retrieval was based on the inversion of a simple Water Cloud Model with gaps; single estimates of stem volume are then combined to obtain the final multi-temporal estimate. The model matched the relationship between the SAR backscatter and the stem volume under all configurations. The retrieval relative Root Mean Square Error (RMSE) differed depending upon environmental conditions, polarization and look angle. Stem volume was best retrieved in Krycklan using only HV-polarized data acquired under unfrozen conditions with a look angle of 34.3° (relative RMSE: 44.0%). In Remningstorp, the smallest error was obtained using only HH-polarized data acquired under predominantly frozen conditions with a look angle of 34.3° (relative RMSE: 35.1%). The relative RMSE was below 30% for stands >20 ha, suggesting high accuracy of ALOS PALSAR estimates of stem volumes aggregated at moderate resolution.

forest

Sweden

stem volume

backscatter

ALOS PALSAR

boreal

retrieval

Author

Maurizio Santoro

Gamma Remote Sensing AG

Leif Eriksson

Chalmers, Earth and Space Sciences, Radar Remote Sensing

J. E. S. Fransson

Swedish University of Agricultural Sciences (SLU)

Remote Sensing

20724292 (eISSN)

Vol. 7 4 4290-4317

Driving Forces

Sustainable development

Subject Categories

Remote Sensing

Forest Science

Roots

Basic sciences

DOI

10.3390/rs70404290

More information

Latest update

9/6/2018 1