Citation:
Keith Morrison and Mark L. Williams. High Resolution PolInSAR with the Ground-Based SAR (GB-SAR) System: Measurement and Modelling. Geoscience and Remote Sensing Symposium, 2005. (IGARSS '05). Proceedings 2005 IEEE International. Volume 2, 25-29 July 2005 Pages 1105 – 1108.
Abstract:
Ground-based work is necessary for a
comprehensive assessment of the operational potential and
limitations of PolInSAR in airborne and satellite SAR
applications. A study is made of the performance and usefulness
of the UK’s Ground-Based SAR (GB-SAR) Outdoor System in
high-resolution PolInSAR studies of vegetation using modeling
results. The facility provides fully-polarimetric L- through X-band
imagery down to a resolution of several wavelengths.
However, the measurement process is slow in relation to pulsed
systems as it requires the antenna head to be mechanically
scanned across an aperture. The PolInSAR technique requires
high coherence between interferometric image pairs, and the
long data acquisition times raise the question of temporal
decorrelation. We developed two models incorporating motion, a
physics-based model and a signal processing model. The former
incorporates a PolInSAR crop simulator employing the distorted
Born approximation, applied to a simulated canopy of wheat
plants based on field-collected physiological measurements. GB-SAR
simulations of mature wheat canopies suffering a range of
wind-blown disturbances are examined for coherence stability.
These calculations permit the analysis of the behaviour of
coherence with system and canopy descriptive parameters, such
to quantify the suitability and performance of measurement
environments for PolInSAR analysis. The models indicate that
clutter motion will degrade interferometric performance both
during aperture formation, and between repeat-pass observation.
However, we conclude that the GB-SAR system will be robust to
small amounts of clutter motion and will serve as a suitable tool for PolInSAR experimental studies.