Microwave Radiometric Features of Mediterranean Forests: Seasonal Variations

摘要

Airborne microwave radiometric measurements were carried out in June 1999 and January 2002 on three forest stands in Tuscany (Italy), in order to investigate the the potential contribution of microwave radiometry in analysing the differences between summer and winter features of trees. The analysis of the collected data pointed out that the use of microwave emission at the highest frequencies makes it possible to separate between several forest types, whereas L-band emission is more related to tree biomass. At low biomass and low frequency, emission is more affected by the seasonal differences, since contributions from soil and from soil-trunk interaction are important. For higher values of biomass and/or frequency emission is mostly dominated by branches and less sensitive to season.