Workshops

Tutor: Dr. Delphine Cerutti, Dr. Jens Klare, Stephan Palm, Dr. Diego Cristallini (all Fraunhofer FHR)
Research Interests: Array-based radar imaging, SAR, MTI

In this workshop you will learn how to simulate SAR raw data and how to process these data to obtain a focused SAR image. For this purpose, a range-Doppler algorithm will be implemented. From the focused SAR image of a single point target, the resolution in range and azimuth will be estimated and compared with the theoretical radar resolution. The influence of windowing functions on SAR imagery will be also investigated. In a second part of the workshop you will focus real SAR data, which were acquired with the radar system AER II of Fraunhofer FHR, using the implemented SAR processor. Finally, in the third part of the workshop, the impact of target motion on SAR focusing will be analyzed.

The workshop is done using Matlab. Basic functions will be used to ensure that all the students can follow the workshop and actively participate regardless of their programming skills.

Tutor: Dr. Diego Cristallini, Dr. Delphine Cerutti-Maori, Dr. Jens Klare, Stephan Palm (all Fraunhofer FHR)
Research Interests: Array-based radar imaging, SAR, MTI, DPCA, ATI

This workshop deals with the advanced processing of SAR data. Differently from the ‘SAR for beginners’, some preliminary experience in SAR signal processing are foreseen. The workshop is organized in a modular way. In the first part, SAR data from stationary point-like scatterers will be simulated and then focused. This first part is analogue to the ‘SAR for beginners’ workshop. In the second part, the effects of moving targets on SAR images will be addressed. Specifically, target motions in along- and in across-track will be simulated and their effects on the resulting SAR image will be investigated. In the third part, the SAR simulator will be extended to a multi-channel scenario. Here, SAR-GMTI techniques will be implemented, to get in depth understanding on how multi-channel processing can be useful to discriminate between stationary and moving targets.

Tutor: Dr.-Ing. Thomas Dallmann, Fraunhofer FHR

Research Interests: Radar polarimetry

If an electromagnetic wave with a defined polarization hits a surface, the polarization changes depending on the physical properties of the surface. A radar which is able to radiate and/or receive differently polarized waves can thus be used to analyze the physical properties of objects. Such polarimetric radar systems make it possible to exploit information not available from conventional radars. The obtained information can be used for signature analysis, target classification, bio- and geophysical parameter inversion, biomass estimation and more. Today's applications range from remote sensing to automotive radar and beyond.

The Workshop is split into two main parts. The first part covers the fundamental principles of polarimetry and gives an overview of different decomposition techniques. Based on simple examples, we will try out and discuss polarimetric concepts and present them within the workshop.

In the second part we will make use of polarimetric SAR data and learn how to visualize polarimetric quantities and to find meaningful representations of polarimetric information. An educational tool called POLSAR Pro will support the workshop to gain a deeper understanding of the underlying theory and analysis techniques of Polarimetric SAR data.

Tutor: Dr. Diego Real, IREA / Italy
Research Interests: Interferometric SAR

The workshop will focus on crucial aspects of Interferometric SAR systems. Exercises on real dataset samples will be addressed in order to investigate the aspects related to interferometric and differential interferometric processing. This involves practical works on the generation of interferograms and coherence maps. Furthermore, common band filtering for mitigation of effects of spatial decorrelation will be addressed, still in the framework of a real data experiment, to assimilate the concepts and characteristic parameter of SAR interferometric processing. Finally, a focus on the differential interferometry aspects will conclude the workshop.

Tutor: Dr. Stefano Turso (Fraunhofer FHR)
Research Interests: Radar system design, RF circuit design, Phased-Array, Antenna design, FPGA

By means of a hands-on exercise, the workshop is designed to let participants experiment with several crucial aspects to be considered when designing a pulsed radar with both mechanically or electronically steered array antenna. On the basis of genuine specifications for commercial maritime radars, topics like system architecture, power budget, background noise, pulse design, antenna arrays, feeding networks will be addressed. Dependencies in between different design areas will be highlighted to learn which parameters play a major role in setting up the overall performance. Tutoring will be provided to reach the workshop goals and achieve a system level overview of the many aspects involved in a radar design.

Tutor: Prof. Dr. Daniel O’Hagan, Dr. Philipp Wojaczek, Fraunhofer FHR
Research Interests: Bistatic and Passive Bistatic Radar (PBR) systems, VHF radars, LO target design, noise radar

This workshop sets the scene for a fictional scenario that requires use of a radar for the surveillance of a site of strategic significance and value. The tasks that the radar must perform to ensure the survivability of the important site can be deduced by reading through the Mission Description; however, the precise radar operating requirements are formulated more concretely towards the end of the Mission Description. For reasons that will become apparent in the Mission Description, a Passive Bistatic Radar (PBR) using illuminators of opportunity is the air surveillance solution most favoured for the protection of the important site in this particular example.

This workshop provides a detailed description of the surveillance problem and states the reasons why a bistatic radar is considered for deployment. All the relevant theory necessary to complete this workshop is presented in the accompanying lecture slides.
The working group will be tasked with evaluating the potential performance of a bistatic radar to address the stated requirements. Tasks will include a theoretical analysis of the signals of opportunity and the advantages and disadvantages of each. The theoretical detection range will be calculated for the different transmitters for given probabilities of detection and false-alarm. Furthermore, as a result of heavy industry operating close to the radar site, the interference floor of the system increases, thereby decreasing the radar sensitivity. Detection ranges will have to be re-evaluated in this context.

The tasks in this workshop will exercise most to the practical considerations that must be undertaken with a passive radar design. The level of Direct Signal Interference (DSI) will have to be estimated as well as methods for its suppression. Transmit antenna beam-tilt may limit the detection of high-altitude targets and this too will have to be analysed.

The tasks in this workshop are tailored to be completed by those who have no particular prior knowledge of bistatic radar systems. However, by the end of the workshop the participants should have a solid comprehension of the principles and practice of bistatic radar.

Tutor: Rajat Awadhiya, Manjunath Thindlu Rudrappa, Dr. Marcus Albrecht (all Fraunhofer FHR)
Research Interests: Signal Processing, Space, Detection

Satellites in low earth orbits are crucial for scientific earth observation and telecommunication. However, these satellites are at increasing risk of collision with space debris objects – for example spent rocket stages.

Placing satellites on safe orbits requires the observation of debris objects by radar systems.
In this workshop you will experience crucial elements of developing the signal processing algorithm for a space debris observation radar system. You will implement signal simulation and signal processing algorithms – from satellite orbits up to processed radar data.
Content:
1. Compute satellite orbits and derive radar observation parameters (range, Doppler, etc.)
2. Apply the radar equation to space debris observation
3. Simulate the received signal based on satellite orbits
4. Implement a range compression algorithm
5. Detect the simulated satellite in the data

In the workshop you will apply in practice what you learned in the lectures:
• Radar equation [Radar fundamentals]
• Range compression / Matched filtering [Radar fundamentals]
• Resolution [Radar fundamentals]
• Ambiguity function [Radar fundamentals]
• Range cell migration [SAR fundamentals]
• Coherent processing [Radar fundamentals]
• Antenna gain computation [Antennas]