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International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Several different kinds of signal are transmitted through only one carrier in microwave unified telemetry tracking & control system(MUTTCS), which has replaced separate system to accomplish all TT&C functions, and has been widely used now. This paper analyses the advantages and disadvantages of general subcarrier frequency-division MUTTCS, then the principle and performances of advanced spread spectrum MUTTCS(SS-MUTTCS) are discussed in detail. The inherent ranging ability of PN code and the speciality of spread spectrum modulation realize the complete unification including measurement of range, velocity and angle as well as telemetry, telecontrol and communication functions. At the same time, the contradiction between range and velocity measurement in precision, resolution and measuring range can be solved. With CDMA technology, the signal and equipment of multi-target or multi-station TT&C can be unified easily. SS-MUTTCS operates under low S/N, low threshold, low power spectrum density and wide spectrum range, so it meet the requirements of electronic warfare and ECM, with high performance of safety, security, anti-intercept and anti-interference. Therefore, SSMUTTCS is becoming an important trend of modern vehicle TT&C system.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During engine and airfield performance testing it is often necessary to acquire weather data at the airfield where the test is being conducted. The airborne data acquisition system (DAS) acquires data associated with flight parameters. A separate system records airport weather conditions. Many times the separate system is an Automated Terminal Information Service (ATIS) or the ground crew relaying wind speed, wind direction and temperature from a weather station. To improve this system, the weather station is designed to acquire and store the data in memory. Utilizing a second DAS that is remote to the airborne DAS poses several problems. First, it is undesirable to have many different data acquisition systems from which to process data. The problem then develops into one of integrating the ground weather DAS with the existing airborne DAS. Other problems of system integrity, compatibility and FCC licensing exist. Complete system integration while maintaining integrity and compatibility is overcome by controlling signal format, flow and timing and is discussed in detail. Further discussion of the issue of transmission is overcome by a technique called spread-spectrum and is used in accordance with FCC rules and regulations.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Location and tracking of personnel and assets is a lucrative enterprise that has seen much expansion in the last decade or two. This expansion is coupled with the rise in popularity of GPS-based technologies. It has become common practice for businesses to track and manage vehicle fleets with GPS enabled devices. We use GPS to navigate while driving our cars, to keep track of our loved ones and we even have GPS receivers in our cell phones. Unfortunately, GPS technology has a few limitations. It can only be used in areas with a clear view of the sky, as line-of-sight must be maintained with at least four satellites at all times. This precludes the use of GPS indoors or in heavily built-up areas. GPS receivers are also still quite expensive. This thesis developed and implemented a strategy for Localised Position Location. Several possible solutions were investigated. Spread Spectrum was selected as the best method to develop into a working example. The characteristics of Spread Spectrum signals and Pseudo-Noise Codes were investigated in some detail, which led to the proposal of several simulation models. These simulations suggested that a simple configuration consisting of a transmitter, sliding correlator, bandpass filter and RF power detector can effectively track a stationary target. A transmitter was designed and implemented and was then used in a simplified measurement to corroborate the predictions made by earlier simulations. With results looking positive it was decided to continue with the design and implementation of a receiver. A complete transmitter/receiver system allowed for extensive measurements to be made. The physical measurements agreed with simulated predictions, confirming that the proposed position location strategy is effective. / AFRIKAANSE OPSOMMING: Die toenemende gewildheid en toeganklikheid van GPS-gebaseerde opsporingstegnologie het gelei tot ‘n geweldige toename in die verkope van toerusting om die beweging van besigheidsbates te monitor en bestuur. Selfs op die persoonlike ontspanningsmark vind GPS-tegnologie toenemend aanklank met vervaardigers van selfone en voertuignavigasietoerusting. GPS-gebaseerde opsporingstegnologie het egter beperkinge, omdat dit te alle tye direkte oogkontak moet behou met minstens vier satelliete. Gevolglik kan GPS-gebaseerde opsporingstegnologie nie binnenshuis of in erg beboude gebiede gebruik word nie. GPS ontvangers is ook redelik duur. Hierdie thesis het `n strategie vir Gelokaliseerde Posisie Bepaling ontwikkel en geïmplementeer. Ondersoek is ingestel na `n verskeidenheid van moontlike oplossings. Strek Spektrum is gekies as die beste metode om verder in `n werkende voorbeeld te ontwikkel. Die eienskappe van Strek Spektrum seine en Pseudo-Ruis Kodes is in detail bestudeer, wat gelei het na die opstelling van `n aantal simulasie modelle. Hierdie modelle dui aan dat `n eenvoudige opstelling, bestaande uit `n sender, glykorellator, banddeurlaat filter en `n RF drywingsmeter doeltreffend aangewend kan word om `n stilstaande teiken te monitor. `n Sender, wat in `n vereenvoudigde meetopstelling gebruik kon word om van die voorspellings wat vroeër gemaak is te staaf, is hierna ontwerp en gebou. Met positiewe resultate is daar besluit om voort te gaan met die ontwerp en bou van `n ontvanger. Met `n volledige sender/onvanger stelsel was dit moontlik om uitgebreide meetings te neem. Die fisiese meetings stem ooreen met die simulasies se voorspellings, wat dien as bevestiging dat die voorgestelde strategie vir posisie bepaling doeltreffend aangewend kan word.

Fourier telescopy imaging is a recently-developed imaging method that relies on active structured-light illumination of the object. Reflected/scattered light is measured by a large “light bucket” detector; processing of the detected signal yields the magnitude and phase of spatial frequency components of the object reflectance or transmittance function. An inverse Fourier transform results in the image. In 2012 a novel method, known as time-average Fourier telescopy (TAFT), was introduced by William T. Rhodes as a means for diffraction-limited imaging through ground-level atmospheric turbulence. This method, which can be applied to long horizontal-path terrestrial imaging, addresses a need that is not solved by the adaptive optics methods being used in astronomical imaging. Field-experiment verification of the TAFT concept requires instrumentation that is not available at Florida Atlantic University. The objective of this doctoral research program is thus to demonstrate, in the absence of full-scale experimentation, the feasibility of time-average Fourier telescopy through (a) the design, construction, and testing of smallscale laboratory instrumentation capable of exploring basic Fourier telescopy datagathering operations, and (b) the development of MATLAB-based software capable of demonstrating the effect of kilometer-scale passage of laser beams through ground-level turbulence in a numerical simulation of TAFT. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

Abstract The primary mission of the Finnish Air Force is to ensure a continuous surveillance and policing of the national airspace. The wartime mission is defensive counter-air fighter operations. Implementation of the air surveillance is carried out mainly with air surveillance radars – policing and defensive actions with fighters. A foundation to a well-executed flight operation is a situation awareness. Pilots have to have a real time air picture in their use, i.e., exact information of the own and enemy’s fighters, and instructions of the mission command. The later has to have information for example about the remaining flight time of the fighters. To keep up the situation awareness the fighters participating the flight operation and the mission command on the ground are connected via real time robust communications system. In this thesis, the system development of the experimental SIHTI (Suomen ilmavoimien hajaspektritietovuo) spread spectrum data link fulfilling the national requirements is considered from the requirement specification to the performance measurements of the airproof prototype. The SIHTI system, which has to be secure, robust and having good LPD/LPI (Low Probability of Detection/Low Probability of Interception) properties has to enable bidirectional transmission between fighters and base stations as well as the fighters themselves. The SIHTI system has to operate in the case when many of similar nets are operating simultaneously in the same region and under heavy jamming. The system concept and its implementation has to be configurable so that an end user and a maintenance of the system can affect on the performance of the system only via parameters and changes in algorithms. In this thesis, it will be shown that the experimental SIHTI prototype with minor changes can fulfil the set requirements. / Tiivistelmä Suomen ilmavoimien perustehtävä on kansallisen ilmatilan jatkuva valvonta ja vartiointi sekä sodan aikana ilmatilan puolustus. Ilmatilan valvonta hoidetaan pääasiassa ilmavalvontatutkilla – vartiointi ja puolustus sotilaskoneilla. Sotilaskoneiden tehokkaan toiminnan edellytyksenä on tilannetietoisuus. Lento-operaatioon osallistuvilla tahoilla tulee olla käytettävissä ajan tasalla oleva ilmatilannekuva eli tarkat tiedot omista ja vastapuolen koneista, taistelujohdon toimintaohjeet sekä tietoa muun muassa operaatioon osallistuvien koneiden jäljellä olevasta toiminta-ajasta. Tilannetietoisuuden ylläpitäminen edellyttää, että lento-operaatioon osallistuvia lentokoneita ja maassa olevaa taistelujohtoa yhdistää reaaliaikainen varmatoiminen tiedonsiirtoyhteys. Tässä väitöskirjassa tarkastellaan kansallisen sotilasilmailun tarpeet täyttävän lentokelpoisen SIHTI (Suomen ilmavoimien hajaspektritietovuo) -hajaspektritiedonsiirtokoejärjestelmän järjestelmäkehitystä aina vaatimusmäärittelystä lentokelpoisen koelaitteiston suorituskykymittauksiin. Turvallisen, varmatoimisen ja vaikeasti tiedusteltavan tiedonsiirtojärjestelmän tulee mahdollistaa niin lentokoneiden kuin lentokoneiden ja maa-asemien välinen kaksisuuntainen sanomansiirto useiden lähekkäin toimivien verkkojen tapauksessa hyvinkin voimakkaassa tahallisessa häirinnässä. Tiedonsiirtojärjestelmässä ja sen toteutuksessa tulee olla myös riittävä määrä muunneltavuutta, jotta järjestelmän loppukäyttäjä ja järjestelmän ylläpitäjä pystyvät parametri- ja algoritmimuutoksin vaikuttamaan järjestelmän suorituskykyyn. Väitöskirjassa osoitetaan, että FH/DS-CDMA (Frequency Hopping / Direct Sequence Code Division Multiple Access)- ja TDMA (Time Division Multiple Access) -monikäyttömenetelmiin pohjautuva SIHTI-koejärjestelmä pystyy pienin muutoksin täyttämään sille asetetut vaatimukset.

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This dissertation exammes two of the rlsing technologies in the world of wireless, cellular communications - CDMA and the software radio. This thesis covers many of the issues related to these two emerging field s of wireless communications, establish ing a theoretical framework for the broader issues of implementation. To this end, the thesis covers many of the basic issues of spread spectrum communications, in addition to establishing the need for, and defining the role of, the software radio. Amalgamation of these two key areas of interest is embellished in a presentation of many of the concerns of implementing a specific CDMA system on a particular type of software radio - the Alcatel Altech Telecomms Flexible Radio Platform. Of primary concern in the research methodology embraced in this thesis is the mastering of a variety of analysis and implementation tools. Once the theoretical background has been substantiated by current expositions, the thesis launches along a highly deterministic route. First, the research issues are tested in a mathematical environment for suitability to the given task. Second, an analysis of the appropriateness of the technique for the software radio environment is undertaken, culminating in the attempted deployment within the hardware environmenl. Rigorous testing of the input/output mapping characteristics of the hardware instantiations created in this manner complements the research methodology with a viability study. This procedure is repeated with many elements of the CDMA system design as they are examined, simu lated, deployed and tested. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2000.

I denna uppsats betraktas två olika bandspridningstekniker och vilken påverkan de har på telekrigsförmågan. Uppsatsen svarar på frågan: Vilka möjligheter finns att bedriva signalspaning och störning mot radiokommunikation som använder bandspridningsteknikerna frekvenshopp eller direktsekvens? Inledningsvis beskrivs en modell för telekrig mot radiokommunikation, ”telekrigcykeln”. Därefter beskrivs principer för ett radiosystem samt de två bandspridningsteknikerna frekvenshopp och direktsekvens. Slutligen analyseras bandspridningsteknikernas påverkan med hjälp av telekrigcykeln och resultaten diskuteras. Uppsatsen kommer fram till att båda signalerna går att spana mot, direktsekvens innebär större svårigheter för signalspaningen än frekvenshopp. Störning av båda signalerna görs bäst med störsändare som befinner sig nära radiomottagaren, dock är det svårt att placera störsändare nära motståndarens mottagare. / This essay examines two spread-spectrum technologies and what their effects are on the electronic warfare ability. The essay seeks to answer this question: What are the possibilities for signals intelligence and communications jamming against radio communications using one of the two spread-spectrum technologies frequency-hopping and direct sequence? The essay initially describes a model for how electronic warfare against radio communication is conducted, “telekrigcykeln”. It then describes the principles of a radio system as well as the two spread-spectrum technologies frequency-hopping and direct sequence. Using the model “telekrigcykeln” the essay finally analyses and discusses the impact of the spread-spectrum technologies. The essay finds that it is possible to conduct signals intelligence towards both signals, however direct sequence pose bigger problems than frequency-hopping. Both signals are easiest to jam using a jammer in close proximity to the radio receiver. However, close-proximity jammers are harder to place close to the opponent’s receiver.