There remains a wide proliferation of second-generation frequency-modulated conical-scan seekers in the hands of irregular forces, while the understanding of what makes a jam signal effective remains unclear. It is generally known that the jam-to-signal (J/S) ratio, the jam signal frequency, and the duty cycle are the parameters that need consideration when developing an effective jam code, but the effect of using different jammer waveforms is not generally known. The general consensus in the literature seems to indicate that the effective jam signal parameters should be close to those of the target signal. It is known that the jam signal that matches the target signal will only beacon the target and not provide protection, therefore the jam signal should not perfectly match the target signal for effective jamming. However it is not clear which parameters should be close to and which should differ with the target signal. The literature also generally uses the low frequency type of jam signal and the effect of other types of waveforms is not known. Due to the sensitive nature of this topic, a simulation model and a hardware model of the conical scan seeker was not available to the author and as a result a representative simulation model was designed for conducting the experiments. The simulation model was extensively tested and validated to ensure representative behaviour. This study investigated the effect of the critical jam signal parameters against different jammer waveforms namely: the fixed carrier, low frequency, amplitude modulation (AM), frequency-modulation (FM) and the AM-FM jam codes. The study tested the effect of the critical parameters across the different jam waveforms and a comparison of the tested waveforms was conducted. The parameters used to compare the jam signals were the maximum achieved seeker error, the minimum J/S ratio required to achieve a significant effect, the range of effective frequencies or modulation indices and the lowest effective duty cycle. The AM jam signal achieved the greatest seeker error when compared to the other jam waveforms with a maximum error of 1.1°. The AM jam signal however achieves this error, with a J/S ratio of 50. The AM-FM jam signal achieved an error of 0.97° at a J/S ratio of 20 which is less than half of the required J/S ratio with the AM jam signal. The AM-FM hybrid jam signal was found to be the most robust in a wide range of modulation indices. This jam waveform was found to be the least sensitive against changes in the modulation index. The jam signal was found to be less power intensive when compared with other waveforms since significant jam effect was achieved at low J/S ratios. The best parameter combination for this jam signal was a J/S ratio of 20, a modulation index of 2.5, a modulation frequency of 100 Hz and a duty cycle of 50%. The maximum seeker error induced by this parameter combination is 0.97°. With the stated advantages, the AM-FM hybrid jam signal was found to be the most effective jam signal against the conical-scan seeker. Contrary to the general guide provided in the literature, the most effective jam signal does not contain parameters that are similar to the target induced parameters. The conclusion of this work was therefore that the most effective jam signal does not necessarily have to be similar to the target signal to be effective against the conical-scan seeker. The unique result found in this study is attributed to the wide range of jam signal waveforms that were tested. The results show that the effects of the critical parameters (J/S ratio, frequency and duty cycle) vary with the change in jam waveform. / Dissertation (MEng)--University of Pretoria, 2020. / Electrical, Electronic and Computer Engineering / MEng / Unrestricted

Optimization of electronic warfare (EW) receiver scan strategies is critical to improving the probability of surviving military missions in hostile environments. The problem is that the limited understanding of how dynamic variations in radar and EW receiver characteristics has influenced the response time to detect enemy threats. The dependent variable was the EW receiver response time and the 4 independent variables were EW receiver revisit interval, EW receiver dwell time, radar scan time, and radar illumination time. Previous researchers have not explained how dynamic variations of independent variables affected response time. The purpose of this experimental study was to develop a model to understand how dynamic variations of the independent variables influenced response time. Queuing theory provided the theoretical foundation for the study using Little's formula to determine the ideal EW receiver revisit interval as it states the mathematical relationship among the variables. Findings from a simulation that produced 17,000 data points indicated that Little's formula was valid for use in EW receivers. Findings also demonstrated that variation of the independent variables had a small but statistically significant effect on the average response time. The most significant finding was the sensitivity in the variance of response time given minor differences of the test conditions, which can lead to unexpectedly long response times. Military users and designers of EW systems benefit most from this study by optimizing system response time, thus improving survivability. Additionally, this research demonstrated a method that may improve EW product development times and reduce the cost to taxpayers through more efficient test and evaluation techniques.

Thesis--School of Advanced Airpower Studies, 1992. / Shipping list no.: 1998-0921-M. "June 1993." Includes bibliographical references. Also available via Internet from the Air University Press web site. Address as of 10/27/03: http://aupress.au.af.mil/SAAS%5FTheses/Hewitt/hewitt.pdf; current access is available via PURL.

Thesis (Ed. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [126]-137).

Indiana University-Purdue University Indianapolis (IUPUI) / Finding the optimal placement of receiving assets among transmitting targets in a three-dimensional (3D) space is a complex and dynamic problem that is solved in this work. The placement of assets in R^6 to optimize the best coverage of transmitting targets requires the placement in 3D-spatiality, center frequency assignment, and antenna azimuth and elevation orientation, with respect to power coverage at the receiver without overloading the feed-horn, maintaining suficient power sensitivity levels, and maintaining terrain constraints. Further complexities result from the human-user having necessary and time-constrained knowledge to real-world conditions unknown to the problem space, such as enemy positions or special targets, resulting in the requirement of the user to interact with the solution convergence in some fashion. Particle Swarm Optimization (PSO) approaches this problem with accurate and rapid approximation to the electronic warfare asset allocation problem (EWAAP) with near-real-time solution convergence using a linear combination of weighted components for tness comparison and particles representative of asset con- gurations. Finally, optimizing the weights for the tness function requires the use of unsupervised machine learning techniques to reduce the complexity of assigning a tness function using a Meta-PSO. The result of this work implements a more realistic asset allocation problem with directional antenna and complex terrain constraints that is able to converge on a solution on average in 488.7167+-15.6580 ms and has a standard deviation of 15.3901 for asset positions across solutions.

<p>This master thesis investigates different approaches to data compression on common types of signals in the context of localization by estimating time difference of arrival (TDOA). The thesis includes evaluation of the compression schemes using recorded data, collected as part of the thesis work. This evaluation shows that compression is possible while preserving localization accuracy.</p><p>The recorded data is backed up with more extensive simulations using a free space propagation model without attenuation. The signals investigated are flat spectrum signals, signals using phase-shift keying and single side band speech signals. Signals with low bandwidth are given precedence over high bandwidth signals, since they require more data in order to get an accurate localization estimate.</p><p>The compression methods used are transform based schemes. The transforms utilized are the Karhunen-Loéve transform and the discrete Fourier transform. Different approaches for quantization of the transform components are examined, one of them being zonal sampling.</p><p>Localization is performed in the Fourier domain by calculating the steered response power from the cross-spectral density matrix. The simulations are performed in Matlab using three recording nodes in a symmetrical geometry.</p><p>The performance of localization accuracy is compared with the Cramér-Rao bound for flat spectrum signals using the standard deviation of the localization error from the compressed signals.</p>

<p>Uppsatsen är skriven med utgångspunkt i att understödjande förbands bidrag i operationer i stadsmiljö sällan nämns i reglementen, samt att förståelse för hur telekrigsförband uppträder och deras unika förmågor är generellt sätt låg inom försvarsmakten. Mitt syfte är att tydligöra hur en telekrigsenhet med dess unika förmåga kan bidra till lösande av uppgifter i en MOUT-operation. I min uppsats försöker jag med hjälp av ett teoretiskt synsätt svara på vad en telekrigsenhet kan bidraga med i en operation av ett MOUT-koncept. För att besvara denna fråga använder jag mig av en kvalitativ textanalys och intervjuer. Resultatet som framkommer är att en telekrigsenhet är en unik resurs som kan bidra med unika underrättelser och verkan, främst kopplat till stegen förstå, få bättre lägesuppfattning samt att kunna engagera motståndaren i en MOUT-operation.</p> / <p>With a theoretical approach this essay aims to answer the question; What can an electronic warfare unit can contribute with to an operation in a MOUT concept? To answer this question I use a qualitative text analysis and interviews. The result obtained is that an electronic warfare unit is a unique resource which contributes with unique intelligence and effects. This is mainly linked to the steps to understand, gaining a better situational awareness and to be able to engage the opponent in a MOUT operation.</p>

<p>Det svenska försvarets övergång till insatsförsvar och internationella insatser har lett till omfattande förändringar av Försvarsmakten. Inom ramen för detta är ny amfibiebataljon under framställning. Denna bataljon bör agera med telekrigsförmåga och därmed undersöks vilken typ av system bör vara lämpligt för amfibiebataljon 2014. Initialt så framställs en genomgång av elektronisk krigföring för att skapa förståelse för ämnet och telekrigsförmågans utveckling i både Armén och Marinen. Amfibiebataljon 2014 presenteras för att beskriva förbandet som amfibieregementet skall ansvara för. För att förstå det sammanhang i vilket amfibiska styrkor skall använda sig av telekrigssystem, så beskrivs tre amfibiska scenarier för att möjliggöra en kommande analys. En intervju med tre nyckelpersoner inom det svenska försvaret förs fram för att säkerställa att aktuell information används i uppsatsen. Analysdel av uppsatsen kommer att baseras på de olika telekrigssystemen med en metod att utvärdera dessa från Försvarsmakten grundläggande förmågor. Därefter kommer de system som skall ha utvärderats på grunder av för- och nackdelar sättas i kontext i samband med de scenarier som har lagts fram. Målet är att ta reda på vilket system som är till nytta för amfibiebataljon, samt för- och nackdelarna med ett sådant system. Resultaten visar att ett medelstort system bör användas av amfibiebataljon på grund av sin förmåga till verkan samtidigt som den uppfyller krav på skydd och rörlighet. Dessutom bör ett lätt telekrigssystem användas av amfibiebataljonen på grund av dess kapacitet inom rörlighet och underrättelseinhämtningskapacitet.</p> / <p>The Swedish Armed Forces transition to a force specified against international missions has brought extensive transformations of the armed forces. As part of this a new amphibious battalion 2014 is in the progress of being organized. This battalion should act with electronic warfare capabilities and thus, this essay will investigate what kind of system should be appropriate for the amphibious battalion. The essay begins with a review of electronic warfare in order to create an understanding in general as well as its development in both the Army and the Marine forces. Amphibious battalion 2014 is also presented to describe the upcoming unit which the amphibious regiment shall be responsible for. To understand the context in which amphibious forces shall make use of electronic warfare systems, descriptions of three amphibious warfare scenarios are presented to allow an upcoming analysis. An interview with three key personnel within the Swedish Armed Forces is brought forward to ensure that current information is used in the essay. The analysis part of the essay is based on the various electronic warfare systems with a method of evaluating these from the Armed Forces essential abilities. Thereafter, the systems will be evaluated on the basis of the produced pros and cons in correlation with the operation scenarios that has been presented. The goal is to find out which system is of use for the amphibious battalion, and the pros and cons of such a system. The results indicates that a medium-sized system should be used by the amphibious battalion because of its ability for effect while it meets demands for protection and mobility. Also, a light electronic warfare systems should be used by the amphibious battalion because of its capacity in mobility and intelligence gathering capability.</p>

Det svenska försvarets övergång till insatsförsvar och internationella insatser har lett till omfattande förändringar av Försvarsmakten. Inom ramen för detta är ny amfibiebataljon under framställning. Denna bataljon bör agera med telekrigsförmåga och därmed undersöks vilken typ av system bör vara lämpligt för amfibiebataljon 2014. Initialt så framställs en genomgång av elektronisk krigföring för att skapa förståelse för ämnet och telekrigsförmågans utveckling i både Armén och Marinen. Amfibiebataljon 2014 presenteras för att beskriva förbandet som amfibieregementet skall ansvara för. För att förstå det sammanhang i vilket amfibiska styrkor skall använda sig av telekrigssystem, så beskrivs tre amfibiska scenarier för att möjliggöra en kommande analys. En intervju med tre nyckelpersoner inom det svenska försvaret förs fram för att säkerställa att aktuell information används i uppsatsen. Analysdel av uppsatsen kommer att baseras på de olika telekrigssystemen med en metod att utvärdera dessa från Försvarsmakten grundläggande förmågor. Därefter kommer de system som skall ha utvärderats på grunder av för- och nackdelar sättas i kontext i samband med de scenarier som har lagts fram. Målet är att ta reda på vilket system som är till nytta för amfibiebataljon, samt för- och nackdelarna med ett sådant system. Resultaten visar att ett medelstort system bör användas av amfibiebataljon på grund av sin förmåga till verkan samtidigt som den uppfyller krav på skydd och rörlighet. Dessutom bör ett lätt telekrigssystem användas av amfibiebataljonen på grund av dess kapacitet inom rörlighet och underrättelseinhämtningskapacitet. / The Swedish Armed Forces transition to a force specified against international missions has brought extensive transformations of the armed forces. As part of this a new amphibious battalion 2014 is in the progress of being organized. This battalion should act with electronic warfare capabilities and thus, this essay will investigate what kind of system should be appropriate for the amphibious battalion. The essay begins with a review of electronic warfare in order to create an understanding in general as well as its development in both the Army and the Marine forces. Amphibious battalion 2014 is also presented to describe the upcoming unit which the amphibious regiment shall be responsible for. To understand the context in which amphibious forces shall make use of electronic warfare systems, descriptions of three amphibious warfare scenarios are presented to allow an upcoming analysis. An interview with three key personnel within the Swedish Armed Forces is brought forward to ensure that current information is used in the essay. The analysis part of the essay is based on the various electronic warfare systems with a method of evaluating these from the Armed Forces essential abilities. Thereafter, the systems will be evaluated on the basis of the produced pros and cons in correlation with the operation scenarios that has been presented. The goal is to find out which system is of use for the amphibious battalion, and the pros and cons of such a system. The results indicates that a medium-sized system should be used by the amphibious battalion because of its ability for effect while it meets demands for protection and mobility. Also, a light electronic warfare systems should be used by the amphibious battalion because of its capacity in mobility and intelligence gathering capability.

Uppsatsen är skriven med utgångspunkt i att understödjande förbands bidrag i operationer i stadsmiljö sällan nämns i reglementen, samt att förståelse för hur telekrigsförband uppträder och deras unika förmågor är generellt sätt låg inom försvarsmakten. Mitt syfte är att tydligöra hur en telekrigsenhet med dess unika förmåga kan bidra till lösande av uppgifter i en MOUT-operation. I min uppsats försöker jag med hjälp av ett teoretiskt synsätt svara på vad en telekrigsenhet kan bidraga med i en operation av ett MOUT-koncept. För att besvara denna fråga använder jag mig av en kvalitativ textanalys och intervjuer. Resultatet som framkommer är att en telekrigsenhet är en unik resurs som kan bidra med unika underrättelser och verkan, främst kopplat till stegen förstå, få bättre lägesuppfattning samt att kunna engagera motståndaren i en MOUT-operation. / With a theoretical approach this essay aims to answer the question; What can an electronic warfare unit can contribute with to an operation in a MOUT concept? To answer this question I use a qualitative text analysis and interviews. The result obtained is that an electronic warfare unit is a unique resource which contributes with unique intelligence and effects. This is mainly linked to the steps to understand, gaining a better situational awareness and to be able to engage the opponent in a MOUT operation.