Temporal Characteristics of P-band Tomographic Radar Backscatter of a Boreal Forest
Journal article, 2021

Temporal variations in synthetic aperture radar (SAR) backscatter over forests are of concern for any SAR mission with the goal of estimating forest parameters from SAR data. In this article, a densely sampled, two-year long time series of P-band (420 to 450 MHz) boreal forest backscatter, acquired by a tower-based radar, is analyzed. The experimental setup provides time series data at multiple polarizations. Tomographic capabilities allow the separation of backscatter at different heights within the forest. Temporal variations of these multi-polarimetric, tomographic radar observations are characterized and quantified. The mechanisms studied are seasonal variations, effects of freezing conditions, diurnal variations, effects of wind and the effects of rainfall on backscatter. An emphasis is placed on upper-canopy backscatter, which has been shown to be a robust proxy for forest biomass. The canopy backscatter was most sensitive to freezing conditions but was more stable than ground-level backscatter and full-forest backscatter during non-frozen conditions. The analysis connects tree water transport mechanisms and P-band radar backscatter for the first time. The presented results are useful for designing boreal forest parameter estimation algorithms, using data from P-band SARs, that are robust to temporal variations in backscatter. The results also present new forest remote sensing opportunities using P-band radars.

backscatter

p-band

boreal forest

time series

Author

Albert Monteith

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

Lars Ulander

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

Electric, Computer, IT and Industrial Engineering

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

1939-1404 (ISSN)

Vol. 14 1967-1984

Tower-based radar and geophysical measurements during the BorealScat experiment

European Space Research and Technology Centre (ESA ESTEC), 2016-11-01 -- 2018-04-30.

European Space Agency (ESA), 2016-11-01 -- 2018-04-30.

Mark- och trädfuktighet och deras inverkan på radarsignalen från skog

Hildur och Sven Wingquists stiftelse, 2019-02-01 -- 2020-11-30.

Driving Forces

Sustainable development

Subject Categories

Ecology

Other Earth and Related Environmental Sciences

Forest Science

Other Electrical Engineering, Electronic Engineering, Information Engineering

Areas of Advance

Life Science Engineering (2010-2018)

DOI

10.1109/JSTARS.2021.3050611

More information

Latest update

3/9/2021 1