Retrieval of boreal forest and surface characteristics from ENVISAT multisensor data


Markus Törmä, Juho Lumme, Kirsi Karila




The objective is to develop novel methods to use space-borne remote sensing data for boreal forest ecology and forestry applications with emphasis on such ENVISAT-instruments as ASAR radar and MERIS-spectrometer. The specific applications include: forest inventory, monitoring of soil moisture/frost, determination of the length of growing season, estimation of carbon balance, and land cover classification.

In addition to ENVISAT instrumentation, the research is carried out using historical space-borne data, especially ERS-2 SAR observations. For comparison, extensive ground-based data are collected from selected test areas in Finland including ground/tower-based optical and microwave measurements. The main test site is the SMEAR II Station in Hyytiälä, Southern Finland (Station for Measuring Forest Ecosystem - Atmosphere Relations). SMEAR II station yields continuous measurements on gas exchange, water transport and growth of trees.

The role of our Institute is to take part in data processing and to study the applicability of ENVISAT data to forest classification. Different classifications under study are tree species, biomass, habitat type and soil classification. The main source of data are radar instruments onboard ERS and ENVISAT satellites. Data from MERIS instrument will used to make fuzzy classification of Hyytiälä test area.

Project team: Helsinki University of Technology / Laboratory of Space Technology, University of Helsinki / Department of Forest Ecology, Helsinki University of Technology/Institute of Photogrammetry and Remote Sensing and Tarto Observatory, Estonia.