ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Digital data distribution systems are widely used in Aerospace and Defense products to allow devices to communicate with one another. In many cases it is desirable to monitor the data traffic flowing between two points in a copper or fiber based Operational or Onboard Network System (ONS) for Flight Test Instrumentation (FTI) purposes because these ONS systems may carry important data which can be used without duplicating/installing a specific FTI data acquisition system to receive this data. The two types of network taps that can be used are Inline Network Taps and network end-point taps. This paper examines the usage of Inline Network Taps for FTI applications and how they can support network access strategies and objectives. An Inline Network Tap is a hardware device which allows access to data flowing across a network. These devices are typically active/powered and have a number of ports: a first tap port, a second tap port, and one or more mirror ports. An in-line network tap inserted between the first and second tap port passes all data traffic through unimpeded but also copies that same data to one or more mirror ports. Some Inline Network Tap devices may also pass packets when the tap is not powered or a malfunction is detected on the device via an integrated by-pass function. If the Inline Network Tap device goes offline the unit automatically bypasses the tap connection and data traffic is directed through the bypass directly to network devices. This capability is crucial for inline usage on mission critical network segments that cannot afford the risk of losing the network connection. An in-line network tap can either be based on copper or fiber technology and as a "filterable" network tap can also provide advanced packet filtering capabilities. These filterable network taps can selectively pass data, e.g., based on VLAN ID or other parameters, to a mirror port for deep analysis, monitoring and recording. Another advanced tap function that is presented in this paper is the support for inserting time stamps at the tap level in monitored packets which provides a reference time when the data content of a given packet was generated at a data source. This capability is a significant feature for FTI applications as most ONS systems do not provide time stamped data.

The thesis deals with improving location determination when using time of flight of radio signals to determine the location of a radiator. The goal of this project is to enhance an existing wireless data access point to perform an accurate measurement of the time of arrival of a data signal from a transmitter, and to combine this information with information from additional wireless data access points to determine the location of the transmitter. There have been a number of earlier efforts in indoor location determination system using different technologies. Many of which used signal strength analysis and they have low tolerance to moving obstacles such as humans, which frequently are the most usual dynamic obstacles in indoors. In this thesis, the proposed solution utilizes time stamping and sample correlation to utilize properties of the signal waveform, which has not previously been examined by researchers other than the examiner and advisor. The main contribution of the project is a detailed analysis and design of a solution, as well as a comparison with other potential solutions. The main purpose of this solution is to increase the timing accuracy to below the duration of a single symbol. The wireless device that has been analyzed implements the IEEE 802.11b protocol. Several investigations have been done to determine the best way of extracting information from the 802.11b data frame and symbol sequence; here we utilize a correlator to determine the time of arrival of a specific sequence of symbols in a data frame. The time stamping of a stream of samples has been implemented in an Altera FPGA to get a deterministic computation time. Instead of decoding the incoming I&Q signals and mapping them to bits, the correlator is used to detect the unique sequence containing PSK encoded and Barker code spread scrambled ones , as this sequence always appears at the start of each data frame. The advantage of this approach is that using of samples of the waveform instead of bits gives a significant enhancement in timing resolution. The design documents of this work include detailed descriptions, simulations, and plots. A number of simulations have been done to show the timing accuracy and standard deviation, as well as comparisons with several different approaches. Several potential optimizations have also been discussed in the report. Simulation code for MATLAB and implementation code for the FPGA has been included in appendices in the end of this thesis. / Denna rapport beskriver ett examensarbete som utgår ifrån att förbättra noggrannhet av en lokaliseringsteknik som tillämpar flygtiden av radiosignal för att mäta positionen av utsändaren. Målet av detta arbete är att förstärka en befintlig trådlösdata accesspunkt för att utföra en noggrann mätning av signals anländning från sändaren, och kombinera denna information från ytterliga trådlösdata accesspunkter för att lokalisera sändaren. Det har varit ett antal utvecklingar med olika teknologier för att ta fram en lösning för inomhus lokaliseringssystem. Många av de förslag som har kommit fram tillämpa signalstyrka och har en dålig tolerans av rörande hinder så som människor, vilka är det vanligaste fallet inomhus. Denna rapport ger ett förlag att lösa detta problem med att tillämpa tidstämpel och sampelkorrelation för att utnyttja egenskaper av signalens vågform, ett förlag som inte har blivit undersökt mycket av andra forskare. Stor del av denna rapport består av detaljerad analys och lösningsdesign, plus en jämförelse med andra potentiella lösningar. Meningen med denna lösning är att öka noggrannhet till att felmarginal i tid ska ligga under en symboltid. Den trådlösa enhet som har analyserats implementerar IEEE 802.11b protokollen. Flera undersökningar har utförts för att bestämma det bästa sättet att extrahera information från 802.11b dataramer och symbolsekvenser. För att göra det har vi implementerat en korrelator för att bestämma anländningstid av specifika symbolsekvenser i en dataram. En Altera FPGA har använts för att tidstämpla inkommande sampel för att ge en deterministisk beräkningstid. Istället för att avkoda inkommande I&Q signaler och mappa dem till bitar, har vi valt att implementera korrelator så att den opererar direkt på PSK-modulerade och Barkerkod-spridda ettor, eftersom att det visar sig att denna sekvens alltid visar sig i början av varje dataram. Fördelen med denna lösning är att direktanvändning av sampel ger en signifikant ökning på tidsupplösning jämfört med bitar. Designdokumentet av detta examensarbete består av detaljerade beskrivningar, simuleringar och grafer. Ett antal simuleringar har utförts för att visa tidsnoggrannhet och medelfel, plus jämförelser mellan olkia lösningsförslag. Olika möjliga optimeringar har också diskuterats i rapporten. Simuleringskod för MATLAB och implementeringskod FPGA bifogas i appendix slutet av denna rapport.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / The initial efforts that resulted in the migration of range application traffic to an IP infrastructure largely focused on the challenge of obtaining reliable transport for range application streams including telemetry and digital video via IP packet-based network technology. With the emergence of architectural elements that support robust Quality of Service, multicast routing, and redundant operation, these problems have largely been resolved, and a large number of ranges are now successfully utilizing IP-based network topology to implement their backbone transport infrastructure. The attention now turns to the need to provide supplemental features that provide enhanced functionality in addition to raw stream transport. These features include: *Stream monitoring and native test capability, usually called Service Assurance *Extended support for Ancillary Data / Metadata *Archive and Media Asset Management integration into the workflow *Temporal alignment of application streams This paper will describe a number of methods to implement these features utilizing an approach that leverages the features offered by IP-based technology, emphasizes the use of standards-based COTS implementations, and supports interworking between features.

Abstrakt   Den snabba tekniska utvecklingen har lett till ökad produktion av digitala handlingar/records och transaktioner. Inom e-arkivens domäner, har detta medfört ett ökat tryck på det tekniska området för att kunna garantera autenticitet av bevarad information över tid.          Tidsstämplingstekniker är ett sätt att säkerställa digital information för en särskild tidpunkt och kan användas för att garantera autenticitet av digital information över tid. Denna magisteruppsats undersöker funktionen tidsstämpling inom e-arkivens domäner genom en kvalitativ metod med fem semistrukturerade intervjuer av fem svenska organisationer. I undersökningen ingår också en fallstudie av det svenska innovationsföretaget Enigio Time AB för att ge en förståelse av tidsstämplingstekniker och av deras tjänst time:stamp. Den teoretiska utgångspunkten i denna magisteruppsats är records continuum model med dels dess syn på kontinuitet i handlingar/records och dels dess belysande av skapelseögonblicket av handlingar/records. Den internationella standarden OAIS (Open Archival Information System) används för att hantera digital information och är, i denna uppsats, använd för att analysera hanteringen i dokumenthanteringssystem inom de fem organisationerna.                       Resultaten visar att denna snabba tekniska utveckling har komplicerat dels hanteringen i att säkerställa att digitala handlingar/records inte kan bli manipulerade eller ändrade och dels för att fortsatt kunna garantera autenticitet i ett långtidsperspektiv.                       Undersökningen visar även att organisationerna kan garantera att det bevarade materialet inte kommer att ändras när det väl är inne i arkivet men dess autenticitet, innan de kommer innanför arkivens trösklar, kan aldrig bekräftas. I och med att den moderna tiden producerar och bevarar enorma mängder data så bör detta starta med skapelsen av ett digitalt record tillsammans med bättre strukturerad metadatascheman som är säkrade i tid. / Abstract   The rapid ongoing technical development has led to increased production of digital records and transactions. In the domain of electronic archives, this has put pressure on the technical area in order to guarantee authenticity of preserved information over time. Time stamping techniques are one way to secure digital information at a certain point in time and can be employed to guarantee authenticity of digital information over time. This study examines the function of time stamping within the domain of electronic archives and is conducted with a qualitative method using semi-structured interviews on five Swedish organisations. The study is complemented with a case-study of the Swedish innovation company Enigio Time AB in order to gain understanding in time stamping techniques and their service time:stamp.                       The theoretical framework in this study is the records continuum model with the view of the continuity in records and its illumination of the point of creation. The international standard OAIS (Open Archival Information System) is used by several electronic models to manage digital information and is, in this study, used to analyse the management in record keeping within the five organisations.                       The conclusion is that this rapid technological development has complicated the management of secure digital records from manipulation and guaranteeing the authenticity in a long term perspective.                       The study further shows that organisations may guarantee that records will not change once they are received into the archive but the authenticity of them, before they were delivered, can never be confirmed. Since the modern information era produces and preserves enormous amounts of data, this has to start with the creation of the digital record where better structured metadata schemes are secured in time.

The main aim of this project was to find a practical and accurate method to determine the parameters of a transmission line by using current and voltage measurements. The term line parameters refer to the inherent series resistance and inductance that is found on transmission lines. The line parameters were determined by using the voltage and current measurements from either side of the transmission line. An accurate reference signal is needed to precisely compare the measured signals. The timing signals from GPS units were used to reference the measurements. In a field implementation data transfer of the measured signals would be a necessity which can be accomplished by GPRS modems. Three methods are proposed for determining line parameters. These methods were thoroughly tested in the following ways: 1. A model was built in SIMULINK with known elements and values. The three methods were then applied to the model and simulations were run. The results from the simulations are compared to the known values. 2. A system was built in the laboratory with known parameters. The results gathered from testing the system on all three methods are compared to known values. 3. Finally, the methods were applied to field data from recorders of a utility. This was done to see how well the methods would perform on a real system. Accuracy was determined from what the utility accepts as the correct values. Another focus of the project was to determine the surge impedance loading (SIL) curve from measured data. This curve can be used to determine the loadability limit of the transmission line as well as to visually show at what point the line is operating at any given time. The curve is also useful as it provides insight into the additional reactive power needed for a certain active power transfer. The concept of drawing a SIL curve from actual measurements was first tested by means of simulation. The drawing of the proposed curve is also tested on actual measurements from a transmission line. This investigation posed many challenges. These challenges are discussed in detail in the dissertation. Some of these challenges have easily implementable solutions while others still leave room for further research. The results and findings are published in this document. / Dissertation (MEng (Electrical))--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / MEng / unrestricted