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Conference Presentations by Piotr Ptak

Research paper thumbnail of Forward-scatter Doppler-only Distributed Passive Covert Radar

Forward-scatter geometry places the radar target in diffraction region, resulting in enhanced rad... more Forward-scatter geometry places the radar target in diffraction region, resulting in enhanced radar cross section. Passive covert radar using forward-scatter geometry with Doppler-only geolocation can provide medium to long range early warning capability with very moderate cost. In addition to direct exploitation of target data in command and control systems, the early warning capability can be used for allocation and cueing of other air surveillance resources. Pattern-recognition and inverse-problem approaches have given a computationally light track-before-detect algorithm in time-Doppler domain. Given time series of Doppler observations from two or more transmitter-receiver baselines that observe overlapping volumes of space, various methods can be used for constructing kinematic information. The transmitter-receiver baselines can utilise different or same transmitters as long as the fields of view of the baselines have enough overlap. We present a fault-tolerant network structure of low-cost passive radar stations. Detection and classification results from a proof-of-concept version of such network are presented. The ideas are extensible to correlation receivers and other deployment geometries.

Papers by Piotr Ptak

Research paper thumbnail of Instantaneous doppler signature extraction from within a spectrogram image of a VHF band

IEEE Transactions on Aerospace and Electronic Systems, 2016

Research paper thumbnail of A Dual Data Set of Traversing On-Line Scans and High Resolution Atpa Analysis for Studying CD/MD Separation on Paper Machines

This presentation describes a technique to align a dual data set of paper basis weight data. One ... more This presentation describes a technique to align a dual data set of paper basis weight data. One component of the data set is measured on-line at a paper mill and the other one off-line, using the Advanced Total Paper Analyzer. With this unique dual data the sampling characteristics of on-line scanning can be studied in detail. However, before using the dual data set, both sets of on-line and off-line data should be aligned with respect to each other. Moreover, the data received from the Advanced Total Paper Analyzer requires an alignment as well, to avoid the loss of information due to incorrect order of the data. The alignment, presented here, is based on the crosscorrelation comparison of both sets of data in cross and machine directions. The results indicate that the on-line and off-line data can be aligned with an accuracy close to .

Research paper thumbnail of Aircraft classification based on radar cross section of long-range trajectories

IEEE Transactions on Aerospace and Electronic Systems, 2015

Research paper thumbnail of Web education - remote access laboratories and distributed audience

Research paper thumbnail of CD/MD Separation in Some Data Assimilation Methods for Estimating Paper Web Variation

New separation methods are introduced to separate the measurement data of a paper or paperboard m... more New separation methods are introduced to separate the measurement data of a paper or paperboard machine into its CD and MD profile components: A Kalman-Fourier and an ARMA method. The Kalman-Fourier utilizes the Fourier frequency components to represent variation in both directions, and the ARMA method applies the autoregressive equations to calculate the profile estimations. A simulator is created to test these estimation methods. According to the simulated results, these new estimation methods improve the CD/MD separation accuracy and the control performance.

Research paper thumbnail of Aircraft classification based on instantaneous Doppler curve extraction of VHF band

The paper demonstrates performance of a mathematical model of instantaneous Doppler signature ext... more The paper demonstrates performance of a mathematical model of instantaneous Doppler signature extraction from within VHF band spectrogram image (Ptak et al, IEEE TAES, 2015) when the type of an observed aircraft is addressed. The method proposed in (Ptak et al, IEEE TAES, 2015 October) calculates Radar Cross Section (RCS) profiles and the correlation between them for seven types of aircraft. The analysis is based on data represented by Automatic Dependent Surveillance - Broadcast (ADS-B) trajectory collection and Passive Bistatic Radar with TV station as an illuminator of opportunity, broadly demonstrated in (Ptak et al, IEEE TAES, 2014 50(3)). Throughout the analysis ADS-B data on location of an aircraft is adjusted with the use of extracted Doppler shift information. This ground truth information on location is then used for proper evaluation of RCS profiles and finally validating the extraction method. The method was able to classify common inter-continental aircraft by size clas...

Research paper thumbnail of Reliability of ARMA and GARCH models of electricity spot market prices

Electricity spot market price is notoriously difficult to predict because of the high variability... more Electricity spot market price is notoriously difficult to predict because of the high variability of its volatility that results in prominent price spikes, interlaced with more Gaussian behavior. Such varying volatility has prompted researchers to use GARCH modeling to forecast spot prices. In this article, we study the reliability of an optimally chosen GARCH and its accompanying ARMA model of two electricity spot market price time series using a Markov Chain Monte Carlo (MCMC) method. The MCMC method is used to estimate the parameters of the ARMA-GARCH model. It appears based on this analysis that even an optimally chosen ARMA-GARCH model is not sufficient to explain the behavior of electricity spot market price.

Research paper thumbnail of Long-distance multistatic aircraft tracking with VHF frequency doppler effect

IEEE Transactions on Aerospace and Electronic Systems, 2014

ABSTRACT A multi-static Doppler radar concept based on long-distance VHF frequency recordings is ... more ABSTRACT A multi-static Doppler radar concept based on long-distance VHF frequency recordings is presented and tested in a two receivers, one transmitter configuration. The core of the method is a mathematical model of Doppler shift generation in a passive configuration of many simultaneous transmitting radio stations and receivers that share the Doppler shift information they have recorded. The tracking capabilities of such a multi-static configuration are tested in an off-line experiment over a distance of 400km. Aircraft position was recovered to an apparent precision of 500m. The method also corrects for errors in time synchronization between receivers.

Research paper thumbnail of Forward-scatter Doppler-only Distributed Passive Covert Radar

Forward-scatter geometry places the radar target in diffraction region, resulting in enhanced rad... more Forward-scatter geometry places the radar target in diffraction region, resulting in enhanced radar cross section. Passive covert radar using forward-scatter geometry with Doppler-only geolocation can provide medium to long range early warning capability with very moderate cost. In addition to direct exploitation of target data in command and control systems, the early warning capability can be used for allocation and cueing of other air surveillance resources. Pattern-recognition and inverse-problem approaches have given a computationally light track-before-detect algorithm in time-Doppler domain. Given time series of Doppler observations from two or more transmitter-receiver baselines that observe overlapping volumes of space, various methods can be used for constructing kinematic information. The transmitter-receiver baselines can utilise different or same transmitters as long as the fields of view of the baselines have enough overlap. We present a fault-tolerant network structure of low-cost passive radar stations. Detection and classification results from a proof-of-concept version of such network are presented. The ideas are extensible to correlation receivers and other deployment geometries.

Research paper thumbnail of Instantaneous doppler signature extraction from within a spectrogram image of a VHF band

IEEE Transactions on Aerospace and Electronic Systems, 2016

Research paper thumbnail of A Dual Data Set of Traversing On-Line Scans and High Resolution Atpa Analysis for Studying CD/MD Separation on Paper Machines

This presentation describes a technique to align a dual data set of paper basis weight data. One ... more This presentation describes a technique to align a dual data set of paper basis weight data. One component of the data set is measured on-line at a paper mill and the other one off-line, using the Advanced Total Paper Analyzer. With this unique dual data the sampling characteristics of on-line scanning can be studied in detail. However, before using the dual data set, both sets of on-line and off-line data should be aligned with respect to each other. Moreover, the data received from the Advanced Total Paper Analyzer requires an alignment as well, to avoid the loss of information due to incorrect order of the data. The alignment, presented here, is based on the crosscorrelation comparison of both sets of data in cross and machine directions. The results indicate that the on-line and off-line data can be aligned with an accuracy close to .

Research paper thumbnail of Aircraft classification based on radar cross section of long-range trajectories

IEEE Transactions on Aerospace and Electronic Systems, 2015

Research paper thumbnail of Web education - remote access laboratories and distributed audience

Research paper thumbnail of CD/MD Separation in Some Data Assimilation Methods for Estimating Paper Web Variation

New separation methods are introduced to separate the measurement data of a paper or paperboard m... more New separation methods are introduced to separate the measurement data of a paper or paperboard machine into its CD and MD profile components: A Kalman-Fourier and an ARMA method. The Kalman-Fourier utilizes the Fourier frequency components to represent variation in both directions, and the ARMA method applies the autoregressive equations to calculate the profile estimations. A simulator is created to test these estimation methods. According to the simulated results, these new estimation methods improve the CD/MD separation accuracy and the control performance.

Research paper thumbnail of Aircraft classification based on instantaneous Doppler curve extraction of VHF band

The paper demonstrates performance of a mathematical model of instantaneous Doppler signature ext... more The paper demonstrates performance of a mathematical model of instantaneous Doppler signature extraction from within VHF band spectrogram image (Ptak et al, IEEE TAES, 2015) when the type of an observed aircraft is addressed. The method proposed in (Ptak et al, IEEE TAES, 2015 October) calculates Radar Cross Section (RCS) profiles and the correlation between them for seven types of aircraft. The analysis is based on data represented by Automatic Dependent Surveillance - Broadcast (ADS-B) trajectory collection and Passive Bistatic Radar with TV station as an illuminator of opportunity, broadly demonstrated in (Ptak et al, IEEE TAES, 2014 50(3)). Throughout the analysis ADS-B data on location of an aircraft is adjusted with the use of extracted Doppler shift information. This ground truth information on location is then used for proper evaluation of RCS profiles and finally validating the extraction method. The method was able to classify common inter-continental aircraft by size clas...

Research paper thumbnail of Reliability of ARMA and GARCH models of electricity spot market prices

Electricity spot market price is notoriously difficult to predict because of the high variability... more Electricity spot market price is notoriously difficult to predict because of the high variability of its volatility that results in prominent price spikes, interlaced with more Gaussian behavior. Such varying volatility has prompted researchers to use GARCH modeling to forecast spot prices. In this article, we study the reliability of an optimally chosen GARCH and its accompanying ARMA model of two electricity spot market price time series using a Markov Chain Monte Carlo (MCMC) method. The MCMC method is used to estimate the parameters of the ARMA-GARCH model. It appears based on this analysis that even an optimally chosen ARMA-GARCH model is not sufficient to explain the behavior of electricity spot market price.

Research paper thumbnail of Long-distance multistatic aircraft tracking with VHF frequency doppler effect

IEEE Transactions on Aerospace and Electronic Systems, 2014

ABSTRACT A multi-static Doppler radar concept based on long-distance VHF frequency recordings is ... more ABSTRACT A multi-static Doppler radar concept based on long-distance VHF frequency recordings is presented and tested in a two receivers, one transmitter configuration. The core of the method is a mathematical model of Doppler shift generation in a passive configuration of many simultaneous transmitting radio stations and receivers that share the Doppler shift information they have recorded. The tracking capabilities of such a multi-static configuration are tested in an off-line experiment over a distance of 400km. Aircraft position was recovered to an apparent precision of 500m. The method also corrects for errors in time synchronization between receivers.