<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The view angle range of Sentinel-1 SAR in the Interferometric Wide swath (IW) measurement mode is 29.1° – 46.0°. The dependence of backscatter on the arbitrary local incidence angle is usually corrected using a linear regression model where the incidence angle is a predictor variable. We analysed the whole time series of Sentinel-1 SAR VV-polarised backscatter over the flat 15×15 km test site in Laeva, Estonia (26° 26′ 43″ E; 58° 31′ 56″ N). Time series containing measurements from three different orbits were constructed for 3,159 stands from nighttime data and for 1,105 stands from daytime data. We can confirm that daytime backscatter is systematically greater than nighttime backscatter. We found a significant deviation from linearity in the backscatter dependence on local incidence angle. The empirical finding may be caused by the microwave scattering dependence on local incidence angle or by the influence of Sentinel-1 SAR sub-swath configuration in the Terrain Observation with Progressive Scans SAR (TOPSAR) method that is used for the measurements.</p>
</abstract>

The view angle range of Sentinel-1 SAR in the Interferometric Wide swath (IW) measurement mode is 29.1° – 46.0°. The dependence of backscatter on the arbitrary local incidence angle is usually corrected using a linear regression model where the incidence angle is a predictor variable. We analysed the whole time series of Sentinel-1 SAR VV-polarised backscatter over the flat 15×15 km test site in Laeva, Estonia (26° 26′ 43″ E; 58° 31′ 56″ N). Time series containing measurements from three different orbits were constructed for 3,159 stands from nighttime data and for 1,105 stands from daytime data. We can confirm that daytime backscatter is systematically greater than nighttime backscatter. We found a significant deviation from linearity in the backscatter dependence on local incidence angle. The empirical finding may be caused by the microwave scattering dependence on local incidence angle or by the influence of Sentinel-1 SAR sub-swath configuration in the Terrain Observation with Progressive Scans SAR (TOPSAR) method that is used for the measurements.

The influence of Sentinel-1 SAR sub-swath on the recorded backscatter time-series over managed hemiboreal forests

Forestry Studies

This work is licensed under the Creative Commons Attribution 4.0 International License.

Pildi alamvälja mõju Sentinel-1 SAR mõõtmiste aegridades

The view angle range of Sentinel-1 SAR in the Interferometric Wide swath (IW) measurement mode is 29.1° – 46.0°. The dependence of backscatter on the arbitrary...

The influence of Sentinel-1 SAR sub-swath on the recorded backscatter time-series over managed hemiboreal forests

Article Category: Short communication

Published Online: May 04, 2023

Page range: 90 - 96

Received: Sep 19, 2022

Accepted: Oct 03, 2022

DOI: https://doi.org/10.2478/fsmu-2022-0015

Keywords
Sentinel-1 SAR, incidence angle, hemiboreal forest, time series, normalization

© 2022 Mait Lang et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

The influence of Sentinel-1 SAR sub-swath on the recorded backscatter time-series over managed hemiboreal forests

Article Category: Short communication

Published Online: May 04, 2023

Page range: 90 - 96

Received: Sep 19, 2022

Accepted: Oct 03, 2022

DOI: https://doi.org/10.2478/fsmu-2022-0015

KeywordsSentinel-1 SAR, incidence angle, hemiboreal forest, time series, normalization

© 2022 Mait Lang et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
Sentinel-1 SAR, incidence angle, hemiboreal forest, time series, normalization