Wojciech Komorniczak

The data fusion approach to the priority assignment in the multifunction radar

The paper deals with the problem of the multifunction radar resources management (MFR RM). MFR RM consists of target ranking and tasks scheduling. The paper is focused on the data fusion approach to the target ranking. The data from the radar (objects velocity, range, altitude, direction etc.), IFF system (identification friend or foe) and ESM system (electronic support measures - information concerning a threats electro magnetic activities) are used to decide of the importance assignment for each defected target. The problem is also known as a threat assessment. The main problem consists of the multiplicity of various types of the input information. The information from the radar is of the probabilistic or ambiguous imperfection type and the IFF information is of evidential type. To take advantage of these information sources an advanced data fusion system is necessary. The paper describes a comparison between the fuzzy and the neural network systems which were used in order to perform the threat assessment.

The instability measurements for the unmanned aerial platform as a radar carrier

The paper presents the testbed for the UAS instability measurements. The testbed consists of the aerial vehicle of the miniUAV class. The airplane is equipped with the sensor suite built upon several sensing devices: gyroscopes, accelerometers, magnetometers, GPS receiver and pressure sensors. The data from the sensors is combined in the on-board sensor fusion processor and then transmitted to the ground control station. The aerial vehicle that was acting as a carrier platform is a regular UAV being an equipment of one of the European armies. The testing results show the flying platform instabilities that can be expected during the synthetic aperture radar mission onboard the miniUAV airplane. Several measurements have been taken and the instability characteristics are presented and discussed. The aim of such measurements is to find out the starting point for design of the stabilized platform to be built onboard the UAV. The platform requirements drawn from the presented measurements are taken into account in the review of the possible stabilization solutions. The stabilized platforms were discussed with the respect of the SAR requirements.

Evaluation of a low-cost microUAV platform for sensor suite

The paper presents the idea of a low-cost micro sized unmanned aerial vehicle. Its main purpose is being an aerial platform for a sensor suite. The sensor suite may consist of TV camera, FLIR, ESM, SAR and a set of position telemetric sensors as a GPS/INS or artificial horizon. The paper discusses the specific demands of each kind of sensor type and presents the technology demonstrator which is particularly useful for preliminary tests.

Probabilistic and fuzzy information fusion applied to radar system ranking

The decision making systems make use of heterogeneous information to identify an object class or a target, which are affected by various kinds of imperfection. First, information issued from measures (radar measures, images) of an observation is represented by X variables. Generally, on these X variables, each class can be described through a probability distribution function. These decision systems also integrate expert a prior knowledge to assist the decision. Such information is defined by Y variables and is represented by fuzzy membership function. The question is how to combine appropriately these two kinds of data in order to improve the decision process. In this paper, we present a decision model combining probabilistic and fuzzy data. The decision is defined using a fuzzy Bayesian approach, which takes into account these two imperfections. Only two classes are considered using one X variable and one Y variable. Then an extension is proposed to more complicated cases. To validate the interest of this approach, we compare it with the Bayesian classification and fuzzy classification applied separately to synthetic data. In addition, we will see how our approach can be applied to the problem of radar system ranking, on which system resources are limited and as a consequence, decisions about priorities must be taken. Using the system information sources (i.e. probabilistic: radar measurements, fuzzy: prior expert knowledge, evidential), a comparison between Bayesian classification, fuzzy classification, system decision and the proposed approach is presented.

Sensor set stabilization system for miniature UAV

In this paper we present the concept of multiple sensors data acquisition from onboard of an Unmanned Air Vehicule (UAV). Because of flight instabilities caused by atmosferic movements (winds, thermals etc..) it is necessary to apply active stabilization in order to obtain reliable readings from observation sensors. The most stabilization-demanding sensor is Synthetic Aperture Radar (SAR) and in this paper two methods of stabilization are presented: hybrid (electromechanical) and electronic.

Discretization Process Impact on Compressed LFM Signal Parameters

Digital signal processing is a backbone of a modern radar receiver. Signal discretization and its side effects have significant influence on radar performance. It makes crucial the awareness of the effects, as well as its qualitative and quantitative evaluation. The paper presents the problem of random displacement effect of pulse beginning in accordance to the closest discrete time value. This effect has strong impact on characteristics of pulse compression filter. Characteristics evaluation of the discretization process has been performed on the base of proposed discrete time generation algorithm. The testing results are shown, as well as its discussion and some practical conclusions.

Digital navigation system for miniature quadrocopter UAV

The paper presents the idea of digital navigation system for miniature quadrocopter unmmanded aerial vehilce (UAV). The navigation system is composed of two subsystems: the attitude and heading stabilization and high-level satelite navigation subsystem. Overall quadrocopter concept is presented as well as the solutions used for both navigation subsystems.

The Data Fusion Techniques for Tasks Ranking in Multifunction Radar

The paper presents the problem of tasks ranking in multifunction radar resources management. The data fusion tasks ranking approach is discussed. The neural network, fuzzy inference system, hybrid fuzzy-neural and fuzzy-probabilistic ranking algorithms are presented. The information sources for tasking process have been selected and discussed. Evaluation of the performance of the ranking process is based on defined costs of removal/delay measures. The testing results are shown and discussed.