Daniele Staglianò

3D interferometric ISAR imaging of noncooperative targets

Inverse synthetic aperture radar (ISAR) images are frequently used in target classification and recognition applications. Nevertheless, the interpretation of ISAR images remains problematic for several reasons. One of these is the fact that the image plane cannot be defined by the user but instead depends on the targets own motions and on its relative position with respect to the radar. In order to overcome the problem of interpreting two-dimensional (2D) ISAR images, a method for three-dimensional (3D) reconstruction of moving targets is presented. This method is based on the use of a dual interferometric ISAR system. The interferometric phases measured from two orthogonal baselines are used to jointly estimate the targets effective rotation vector and the heights of the scattering centers with respect to the image plane. The scattering center extraction from the ISAR image is performed by applying a multichannel CLEAN technique. Finally, a 3D image of the moving target is reconstructed from the 3D spatial coordinates of the scattering centers. The effectiveness and robustness of the proposed algorithm is first proven theoretically and then tested against several radar-target scenarios as well as in the presence of noise.

3D target reconstruction by means of 2D-ISAR imaging and interferometry

A method for 3D reconstruction of moving targets based on dual interferometric Inverse Synthetic Aperture Radar (ISAR) is presented in this paper. The interferometric phases measured from two orthogonal baselines are used to jointly estimate the effective rotation vector and the scattering centre heights. The scattering centre extraction from the ISAR image is performed by applying a multichannel CLEAN technique. Theoretical and simulation results are used to prove the effectiveness of the proposed method.

Bistatic three-dimensional interferometric ISAR image reconstruction

A three-dimensional (3D) bistatic inverse synthetic aperture radar (ISAR) imaging method is proposed in this paper. The proposed method makes use of interferometry and technically speaking, produces a 3D target reconstruction by estimating a scattering center position in 3D Cartesian space. The proposed method makes use of a combined ISAR/interferometry technique that also allows the ISAR image plane to orientation to be estimated. Cross- or L-shaped antenna configurations are discussed, and the effects of the baseline length along the horizontal and vertical direction on the scatterers position estimation are analyzed in detail. Finally, numerical simulations are used to evaluate the proposed methods performance.

3D InISAR-based target reconstruction algorithm by using a Multi-Channel ground-based radar demonstrator

A 3D reconstruction algorithm for non cooperative moving targets is proposed in this paper. This method exploits interferometric ISAR imaging (InISAR) to estimate the heights of the dominant scatterers with respect t o the Image Projection Plane. In particular, the interferometric phases measured from two orthogonal baselines are used to reconstruct t he third dimension from 2D-ISAR images. Some aspects that make such approach effective in a real scenario have been faced and their problems solved. In order to verify the effectiveness and the reliability of this technique, data from a suitably designed Multi-Channel ground-based radar has been used.

Ship detection from SAR images based on CFAR and wavelet transform

In this paper the authors propose an innovative two-stage technique for ship detection which is applied to sea synthetic aperture radar (SAR) images. This technique is based on the joint use of Wavelet theory, in particular of the two-dimensional Discrete Wavelet Transform (2D-DWT), and the Constant False Alarm Rate (CFAR) processor. Real data acquired from COSMO-SkyMed (CSK) system have been processed to verify the effectiveness of this proposed new technique.

Fast Detection of Oil Spills and Ships Using SAR Images

In this paper, we show the capabilities of a new maritime control system based on the processing of COSMO-SkyMed Synthetic Aperture Radar (SAR) images. This system aims at fast detection of ships that may be responsible for illegal oil dumping. In particular, a novel detection algorithm based on the joint use of the significance parameter, wavelet correlator and a two-dimensional Constant False Alarm Rate (2D-CFAR) is designed. Results show the effectiveness of such algorithms, which can be used by the maritime authorities to have a faster although still reliable response. The proposed algorithm, together with the short revisit time of the COSMO-SkyMed constellation, can help with tracking the scenario evolution from one acquisition to the next.

Multistatic 3D ISAR image reconstruction

InISAR imaging has proven an effective tool to produce 3D target reconstruction. 3D target reconstruction solves the problems related to the ISAR image interpretation, due to the unknown targets projection onto the image projection plane. Nevertheless, problems related to shadowing are not solved as scatterers that are not visible cannot be detected and located in a 3D coordinate system. To overcome this problem, a multistatic InISAR system is introduced. A method for multistatic 3D target reconstruction that is based on an incoherent technique is proposed and analysed.

Fast detection of maritime targets in high resolution SAR images

In his paper he authors propose an innovative two-sage approach for ship detection which is applied to synthetic aperture radar (SAR) images. This technique is based on he join use of a fast coarse wavelet based detector and a Consant False Alarm Rae (CFAR) detector. Real SAR data acquired by the COSMO-SkyMed (CSK) system have been processed o verify he effectiveness of his proposed technique.

3D ISAR/SAR imaging using multichannel real data

Three-dimensional (3D) target reconstruction provides a more specific description of target features, which would be beneficial for the classification process. In this paper a 3D imaging technique of non-cooperative target acquired by airborne radar system is presented. Traditional two-dimensional (2D) single channel inverse SAR (ISAR) imaging locates each target scattering center in range and Doppler. The third point scatterer coordinate that allows to reconstruct the target in a 3D space is estimated using interferometric phases of two non-parallel baselines and Doppler point scatterer location. The accuracy of the 3D reconstruction depends on the length of the baselines and on the focusing achieved by the 2D imaging process for each channel. The relative movement between the target and the airborne system increases the difficulty to form a well-focused 2D image. The radial component of both radar and target motion affects the image focusing. Moreover traditional image formation method as range/Doppler algorithm introduces further blurring due to the wideband situation. To improve the image quality resulting from standard radial motion compensation techniques and range/Doppler image formation, a method for 2D image processing based on range/velocity data formatting is additionally applied.

Incoherent fusion of 3D InISAR images using multi-temporal and multi-static data

It has recently been demonstrated that Interferometric ISAR is able to reconstruct 3D point-like target images. However, such 3D reconstructions are generally composed of a small amount of points as the number of scatterers that can be accurately extracted from the received signal and placed in a 3D space is limited by the SNR associated to each of them. This lack of information may cause difficulties for targets identification and classification. To overcome this issue, a 3D reconstruction method based on the use of multi-temporal and multistatic data that makes use of an incoherent 3D image fusion technique is presented in this paper.