The full-polarimetric (FP) imaging mode has enriched the information of Synthetic Aperture Radar (SAR) data

and has been widely used in remote sensing applications

e.g. for land cover classification

environmental monitoring

or target detection. However

the application of FP SAR has been constrained by the design and maintenance complexity

power consumption

image swath

and data-downloading rate. Compact Polarimetric (CP) SAR systems not only overcome the drawbacks of FP SAR system

but also keep the FP information to a certain extent. Preliminary results are available in several fields

such as forest parameters estimation

feature classification and target detection. This paper provides an overview of compact polarimetric SAR system fundamentals

describes the methods of FP information reconstruction and decomposition

and summarizes its main research achievements of the last decade. At the end

we give its development trends.