Janusz S. Kulpa

Experimental results of the PaRaDe passive radar field trials

In this paper the results obtained during the trials of the PaRaDe (Passive Radar Demonstrator) are presented. The PaRaDe is a passive radar based on FM radio transmitters developed at Warsaw University of Technology. The targets observed during the trials involved highly maneuvering military targets and commercial airliners. The detection results were compared with data acquired with a Mode-S/ADS-B receiver and an active radar.

Multistatic passive radar based on WIFI - Results of the experiment

In this paper results of an experiment using a multistatic passive radar system based on packet wireless network illuminators are presented. The network consists of several transmitters/receivers that operate on the same channel and exchange data with each other. The passive radar listens to the communication and performs decoding of captured frames, and determines the WiFi network node which was the source of the transmitted frame. The received data stream is divided, based upon the decoded source address, into data streams sent by each network node, after which the separated data streams are processed using classical Passive Coherent Localization methods in order to detect target presence and to localize detected targets. The paper presents details of the experiments performed and their results.

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.

Filter-Based Design of Noise Radar Waveform With Reduced Sidelobes

Noise radars possess several advantageous properties, including low probability of detection and identification, especially when working in continuous-wave mode. One of the main drawbacks of such radars is the occurrence of the masking effect, when a weak target echo is masked by the sidelobes of a strong target echo. The sidelobes of the ambiguity function emerge on the level of the time–bandwidth product below the main peak and are spread in the entire range–Doppler plane. While most approaches to mitigate the masking effect focus on the processing of the received signal, it is possible to move the computation burden to the waveform design phase. This paper describes a filter-based method of creating noise-like waveforms that have very low sidelobes in the area of certain range and Doppler shifts. Both theoretical analysis and measurement results are presented and compared with the lattice filter method of masking effect cancellation.

Precision of target shifts detection using Ka-band ground based noise waveform SAR

There is a growing interest to using of Ground Based SAR for detection of small shifts of various objects. Such equipment can be used for detection of changes in buildings, towers, bridges and natural objects. This can help to predict and prevent possible catastrophes. We have elaborated SAR system capable of detecting such changes using noise radar technology. It uses Ka-band CW noise signals for sounding. The paper is devoted to investigation of differential SAR interferometry technique applied to surface shift detection and estimation using this system. In previous works we gave theoretical consideration of precision dependency on mechanical errors in antenna positioning system and experimentally estimated shift measurement precision for the case of stationary scene using statistical processing of data collected in multiple interferograms. Here we continue investigation of the shifts estimation precision using data collected from the sphere target being shifted. Besides, we investigate influence of the variation of the signal time-bandwidth product onto the shift measurement accuracy. The results agree very well with the previously obtained estimations.

The NATO SET-184 noise radar trials

In the frame of the research activities of the NATO SET-184 group, and thanks to the NATO SET Panel support, experimental tests of the Noise Radar Technology have been carried out in (and near to) Warsaw, in the Autumn of 2013. The paper describes why the particular experiments were made, placing them within the context of previous noise radar trials and with those which will be carried out in summer, 2016 in the frame of the ensuing SET 225 research group. The experimental data set and some representative results are critically described.

Mismatched filter for range sidelobes suppression of pseudo-noise signals

In Continuous Wave (CW) Radars, especially ones transmitting noise signals, the masking effect may cause weak echoes to be completely masked in the sidelobes of strong echo targets. In radars where the transmit and receive antennas are close to each other, the strongest signals are direct crosstalk and close reflections. In this paper a novel mismatched filter is considered for suppressing the range sidelobes of the correlation function. Both simulations and measurement results are presented.

Noise radar concept and design for critical infrastructure surveillance in the SCOUT project

In the paper the system concept of critical infrastructure protection is presented. The described system is developed within the framework of FP7 European Union project on Multitech SeCurity system for intercOnnected space control groUnd staTions (SCOUT). The goal of the SCOUT project is to study, design and analyze a risk-based approach of a security system relying on multiple technologies. The noise radar is one of key sensor in the system, which is able to detect and track a wide spectrum of threats. The signal processing in the noise radar is described along with its applicability in the system.

Power efficiency of high dynamic range noise waveform

Noise radars - radars that use random waveforms as sounding waveforms - are prone to what is known as a masking effect. This occurs when the correlation sidelobes of a strong target echo masks weaker echoes. In order to overcome this limitation, the sounding signals which have correlation functions with suppressed sidelobes may be used. When designing such signals, the power efficiency should be considered, which is increased by decreasing the peak to average power ratio of the waveform. In this paper filter-based waveform design methods are presented and discussed. Three different approaches are analyzed that modify filter-based sidelobe suppression algorithms in order to achieve good power efficiency of the output waveform. Both simulation and measurement results are shown presenting, the benefits of the proposed methods.

Exploitation of noise radar waveforms dynamic range improvement

Noise radars, due to advancements in radio frequency circuits and computational power, have become available in recent years. The main advantages of a noise waveform are the lack of range and Doppler ambiguities, low probability of interception and good electromagnetic compatibility. When several transmitters use different noise waveforms in the vicinity, the receiver noise floor rises according to the power of other waveforms, but no additional interferences are generated. For such reasons the noise waveform is a good candidate for Multiple Input Multiple Output systems. Moreover, noise waveforms may be further prepared to lower its auto- and cross-correlation sidelobes. This paper presents the idea and benefits of noise radar technology. An algorithm for suppressing auto- and cross-correlation sidelobes is discussed and both simulation and real data results are presented.