A multiaspect synthetic aperture radar (SAR) is a novel imaging mode, which supports high spatial resolution, 3-D imaging, and automatic target recognition. However, traditional SAR imaging algorithms will not only degrade SAR images, but also lose significant angular information. Adaptive subaperture imaging algorithms can solve these problems. Distinguishing between anisotropic targets and isotropic targets and extracting the persistence angle are two main steps in these algorithms, both of which will be improved in this letter. First, a better characteristic coefficient, namely, amplitude statistical coefficient (ASC), is proposed to accurately distinguish between anisotropic targets and isotropic targets. Also, change-point detection is introduced to exactly extract the persistence angle. Besides, this letter attempts for the first time to quantitatively assess the characteristic coefficient indicating the anisotropy. For this purpose, two indicators are proposed: anisotropy discrimination index (ADI) and noise resistance range (NRR). The validity of this letter has been verified through the point target simulation data, the microwave anechoic chamber data, and the Gotcha public release data.

As a typical next-generation radar system, multistatic radar operates with distinct transmit and receive antennas, which can obtain three or more simultaneous echo datasets [1] . Such radar system has great potential in increasing the capability, reliability and flexibility of future SAR missions [2] . Recent years, various spaceborne multistatic SAR configurations have been introduced [3] , [4] , and the datasets are relatively scant due to the difficulty in constellation configurations. A multistatic radar system was developed in the anechoic chamber of Laboratory of Target Microwave Properties in 2021, which supposed to provide large amounts of radar cross section (RCS) and imaging data in the future. The amplitude of the RCS was calibrated using a metallic sphere, and the accuracy of the multistatic radar system was validated, which demonstrated the capability of the system.

Height is an important indicator of rice growth condition and phenological period. The Polarimetric SAR Interferometry (PolInSAR) has proven a valuable technique for providing structural metrics of vegetation. Anechoic chamber experiments, allowing a high flexibility in the configuration of operating parameters, such as frequency and baseline, is the most convenient and feasible way to study the potential of PolInSAR in rice height retrieval. In this study, the first PolInSAR measurements of a recently built anechoic chamber, The Laboratory of Target Microwave Properties (LAMP), were presented and analyzed versus frequency and baseline, and rice height was retrieved using the measurement data. The results confirm that LAMP has the ability of PolInSAR, and the height of rice in milk stage is retrieved more precisely in the frequency range of 2.5 to 4.7GHz, when the baseline is 0.5°. The results are expected to contribute to studying and to defining the operation modes for future SAR missions.

Bistatic radar system has attracted lots of studies on earth observation while lacking of data. An indoor bistatic system built in Laboratory of Target Microwave Properties (LAMP) was introduced, and the preliminary bistatic imaging experiments of a metallic cuboid by Inverse SAR (ISAR) was implemented. The characteristics of edge diffraction and specular reflection of electromagnetic wave could be observed clearly on the bistatic images, that highly consistent with the theory of electromagnetic wave. The results demonstrated the capability of this indoor bistatic system, promising to provide more bistatic data for further researches.

This paper mainly analyzes the change of InSAR phase with deformation and displacement by using multifunctional microwave indoor measurement. The experimental target adopts the high-voltage line tower component with strong scattering - metal tripod, which causes “deformation” by padding the bottom of the tripod by 5mm. According to the experimental principle of equal height interference fringes of electromagnetic waves, the measured data before and after deformation of the metal tripod are processed to obtain the phase data at different incident angles, The consistency between the InSAR phase change after phase unwrapping and the actual vertical deformation of the tripod is verified, which provides a basis for the accurate evaluation of InSAR crustal deformation monitoring, and has a good reference for the influence of different working parameters, especially the incident angle on InSAR results.