The Prospect of Radar Remote Sensing in Assessment of Forest above Ground Biomass
International Journal of Agricultural Science and Research
The assessment of forest Above Ground Biomass (AGB) is a major requirement in the current scenario where world faces a serious threat of climate change. The assessments of AGB or carbon stock are carried out in various ways. The allometric equations were developed which were used for the estimation of plot level stand volume. The Land Use Land Cover (LULC) observations and signal measurements by satellite have now-a-days become an important tool in estimation of AGB in forests. The remote
... g techniques were widely used in the assessment of biomass across globe, by establishing relationship between field level biomass and spectral responses/vegetation indices derived from multispectral images. However, frequent cloud coverage hinders the acquisition of all weather data in the optical sensors. The Radar Remote Sensing has an advantage of its own illumination (signal) hand hence independent of sun illumination. The active nature of radar remote sensing makes it applicable to work during day and night, penetrate clouds, canopy, snow, rain, etc. The Synthetic Aperture Radar (SAR) sensors are transmitting microwave energy from 3cm (X-band) to 100cm (P-band). The space borne SAR seems to be very useful for measuring biomass and forest carbon tracking over a large area. The longer wavelength and shorter featuring SAR data is capable to penetrate deep inside the forest and its weak backscatter coefficient from rough surface makes it crucial for the estimation of forest AGB. This review tells about the capabilities of radar remote sensing in the assessment of biomass along with the most adopted methodologies. It deals primarily the application of polarimetric SAR in forest above ground biomass mapping.