The Performance of ERS-1/2 Tandem SAR Coherence Image to Estimate Forest Volume Density in the Northeast of China

Yong Pang(1)

(1) Chinese Academy of Forestry, Yiheyuan Hou, Beijing, 100091, China

Abstract

The Performance of ERS-1/2 Tandem SAR Coherence Image to Estimate Forest Volume Density in the Northeast of China

Yong Pang Zengyuan Li Erxue Chen Xin Tian Research Institute of Forest Resource and Information Technology, Chinese Academy of Forestry Beijing, China Christiana Schmullius Maurizio Santoro Oliver Cartus Department for Geoinformatics and Earth Observation, Friedrich Schiller University Jena, Germany T. Le Toan Centre d'Etudes Spatiales de la Biosphere, Toulouse, France

As the backscatter coefficients from C band SAR saturated soon with forest volume density increasing, a lot of researchers use the interferometic coherence information and repeat pass C band SAR SLC data and it shows good negative relationship with forest volume density increasing. Most of these research areas are high latitude regions, e.g. Sweden, Finland, Siberia of Russia. In the SIBERIA-1 project, the ERS-1/2 tandem SAR data in summer were used successfully to estimate forest volume density in the Siberia, Russia. This paper investigates the possibilities to use the ERS-1/2 tandem SAR data in winter to estimate forest volume density in the Northeast of China. Four typical test sites were selected and the forest maps were collected and digitized. Ten pairs ERS-1/2 tandem SAR data were acquired. The amplitude-driven adaptive coherence estimator was used to generate the coherence image. Then the IWCM (Interferometirc Water Cloud Model) model has been used to analyze the relationship of coherence with forest volume density. The correlation coefficients from the four test sites are all larger than 0.6. The inversion results show good consistent with the volume density from digitalized forest map, especially at the range from 20 to 100 m3/ha.

 

 

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