Artur Gromek

An Advanced SAR Simulator of Three-Dimensional Structures Combining Geometrical Optics and Full-Wave Electromagnetic Methods

Modern research in the field of synthetic aperture radar (SAR) technology requires intensive simulations. The most accurate solution would be achieved by applying full-wave electromagnetic (EM) simulations. However, such an approach requires extremely huge computational efforts, mainly due to the large dimensions of the considered objects with respect to a wavelength. For that reason, most of currently used radar simulators are based on an optical approach, such as geometrical optics (GO). Full-wave EM methods require much more computational resources and are usually applicable to the analysis of geometries no larger than several wavelengths. Nowadays, standard desktop computer platforms are still equipped with too small computational resources to carry out full-wave EM simulations of large scenes considered in radar applications. This paper presents a new concept of hybrid analysis, based on GO enhanced with full-wave EM simulations of larger facets-of the size of a few radar resolution cells. The SAR raw radar simulator described in this paper allows a complex and realistic simulation of any scene under radar observation to be performed. The scene can be defined using any computer-aided-design software generating digital terrain model (DTM). It also allows using real DTMs gathered with, e.g., light detection and ranging systems.

Effective SAR image creation using low cost INS/GPS

In this paper the recent results of Synthetic Aperture Radar (SAR) experiments conducted at the Warsaw University of Technology are presented. In the experiments an SAR radar was mounted on a lightweight airborne platform. The main goal of this experiment was to verify the possibility of obtaining high quality SAR image using navigation data from a low-cost Inertial Navigation System (INS) and classical commercial Global Positioning System (GPS).

Analysis of range migration and Doppler history for an airborne passive bistatic SAR radar

This paper presents an analysis of range migration and Doppler frequency rate-of-change for an airborne passive bistatic radar (PBR) utilizing the synthetic aperture radar (SAR) technique in the imaging of ground objects. The study was carried out for PBR using the Digital Video Broadcasting - Terrestrial (DVB-T) transmitter as an illuminator of opportunity. The results obtained have been verified using both simulated and real data gathered by a PBR mounted on an airborne platform.

Results of high-resolution ISAR imaging of ground moving targets

ISAR (Inverse Synthetic Aperture Radar) is a technique commonly used to produce imagery of moving objects. With advancement in both computational power and high-frequency circuit design, high resolution imaging is now becoming easily available. This paper presents results of high-resolution ISAR imaging of ground targets. The simulations, as well as measurement results are presented.

SAR/InSAR Raw Data Simulator using DTM scene definitions

This paper presents simulation results obtained using new features of an extended version of the SAR/InSAR Raw Data Simulator developed by the Warsaw University of Technology, Poland. The new version of the SAR/InSAR Raw Data Simulator allows for the complex and realistic simulation of any scene under radar observation. The scene can be defined using any CAD software to create a model of the Digital Terrain Model (DTM). It also allows the use of real DTM models gathered using systems such as LIDAR. The main goal of developing the extended version of the SAR/InSAR Raw Data Simulator was to make a useful tool for conducting SAR/InSAR algorithms tests, including most of the phenomena accrued during real SAR acquisition (non-ideal radar platform path, shadowing effect, double and multi-bounds effect, etc.).

SAR-based augmented integrity navigation architecture

This paper presents selected results obtain under SARINA project. SARINA is a SAR-based Augmented Integrity Navigation Architecture proposed by authors of this paper. The main goal of the SARINA project was designing and assessing a novel aircraft Inertial Navigation System (INS) for missile and UAV that will make use of features extracted from SAR/InSAR imagery and on-board terrain landmark database in order to ensure robustness against uncompensated IMU errors due to possible GPS lack of.

Simple X-band polarimetric micro-Doppler analyses of ground moving targets

This paper presents the results of polarimetric micro-Doppler analyses using X-band Frequency Modulated Continuous Wave (FMCW) Radar. In July 2014 the measurement campaign was jointly carried out by Metasensing BV and Warsaw University of Technology. It took place nearby Metasensing premises in Noordwijk, Holland. The radar sensor used in the experiments has a two-channel receiver. Radar data was gathered in two modes: co-polarized (HH) and cross-polarized (HV). During the measurements two cooperating targets were used - a cyclist and a running pedestrian. This paper presents results of the analyses of the observed targets. The obtained results indicate the possibility of distinguishing between different types of objects.

Ground Moving Target Indication in high resolution Synthetic Aperture Radar imaging— a comparison of selected algorithms

In this article three GMTI (Ground Moving Target Indication) algorithms are presented. The algorithms are based on ATI (Along Track Interferometry) signal and show different approaches to moving target indication. The details of each algorithm and results of real radar data processing are presented. Computational complexity of each algorithm is discussed. Plans for future research are outlined.

Comparison of non-coherent change detection methods in SAR imagery

Change detection is the process of identifying differences that have occurred in the terrain surface (EO) at different times (e.g. short time or long time changes, depending on the application). Change detection techniques vary depending on the data source — optical or radar (SAR) imagery. Since both sensors work with different geometry and frequency bands, different distortions and noises are present. Hence different kinds of change detection methods need to be introduced. In this article author will focus on SAR imagery non-coherent change detection.

Airborne targets detection using weather radar

This paper describes airborne targets detection possibilities using weather radar signals. During last two decades air traffics increased significantly. The airborne target like airplane or helicopter is a fast moving object on the radar horizon which gives strong Doppler echoes in received signal. In this paper we would like to show the results of simple processing echo from weather radar on Legionowo and show detected targets, which in our opinion are airborne. Airborne target can be a problem for the radar since it is a source of additional interference especially in wind farm regions. From the other side the weather radar systems after detecting airborne target like small airplane or large bird may share that information with Air Traffic Control systems extending Air Traffic Control knowledge about the airspace situation. Even if the weather radar from its capabilities gives poor resolution of detecting airborne targets it is better to have any poor quality information about the target than no information at all. Airborne target detection possibility using weather radar will be discussed in this paper.