International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper will describe a test technique developed to measure the delays caused by the use of asynchronous multiplexers/demultiplexers. These devices are used for both signal transmission (microwave and fiber optic) and signal recording (especially helical scan digital recorders). The test technique involves the generation and decoding of asynchronous telemetry signals. The bit rates of the telemetry signals are variable. Relative time is embedded in the telemetry signal as a 32-bit data word. The paper will also present measured delays for two multiplexers/demultiplexers for different combinations of bit rates.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / Modern High Density Digital Recorders (HDDR) are ideal devices for the storage of large amounts of digital and/or wideband analog data. Ruggedized versions of these recorders are currently available and are supporting many military and commercial flight test applications. However, in certain cases, the storage format becomes very critical, e.g., when a large number of data types are involved, or when channel-to-channel correlation is critical, or when the original data source must be accurately recreated during post mission analysis. A properly designed storage format will not only preserve data quality, but will yield the maximum storage capacity and record time for any given recorder family or data type. This paper describes a multiplex/demultiplex technique that formats multiple high speed data sources into a single, common format for recording. The method is compatible with many popular commercial recorder standards such as DCRsi, VLDS, and DLT. Types of input data typically include PCM, wideband analog data, video, aircraft data buses, avionics, voice, time code, and many others. The described method preserves tight data correlation with minimal data overhead. The described technique supports full reconstruction of the original input signals during data playback. Output data correlation across channels is preserved for all types of data inputs. Simultaneous real-time data recording and reconstruction are also supported.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / As testing requirements on the ranges require ever more sophisticated cross correlation of data from multiple data acquisition sources, it becomes increasingly advantageous to collect and disseminate this information in a more network oriented fashion. This allows any of the data collected at physically separated sites to be used simultaneously at multiple mission control or data reduction centers. This paper presents an approach that maximizes the use of legacy communication paths and data reduction systems to support an evolutionary migration toward the day when testing can take full advantage of commercial communication protocols and equipment such as OC-3, ATM, etc. One key element of this approach is the packetizing of data at each reception point to provide virtual circuit switching using packet routing. Based on the newly adopted IRIG/RCC 107-98 standard, the system may even be expanded all the way back to the actual sensors. The second key element is the use of the readily available time and timing pulses based on GPS to establish a uniform sampling interval that will allow the cross correlation of data received at different points spread over a wide area.

An optical network technology is the network technology that meets given requirements for a fast and reliable long-distance information transmission. Optical fibres can offer undoubted features where other communication technologies are near their limits or stand in front of insurmountable problems. The intensive research of last years is focused on optical transmission features utilization in the optimal way. Especially an optical signal processing in active network devices without a need for electrical conversation is a topic of high interest. V-Mux is an optical network device that accomplishes above mentioned requirements for modern optical network devices. It is a device that multiplexes and drops an optical signal in its native light form into or from optical fibre. Basic micro electro-mechanical components, which the V-Mux is built from, are high end precise devices. The whole complex V-Mux has to meet strict rules and specifications as the components itself. That is why a control system has to be included in the production process to keep quality and right functionality. This diploma thesis is focused on a development of the testing system that will help in the automated control procedure in the V-Mux production. A brief introduction to optical network technologies and a description of the GPIB bus form a first part of the thesis. The next part focuses on the V-Mux itself and the proposal of the test station with its component description. The last part deals with a developing of the software for the V-Mux testboard and a user application that will be used for the test system initialization.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Neste trabalho, alÃm dos capÃtulos que envolvem a teoria e definiÃÃes, foi basicamente divido em trÃs estudos: Primeiro (capÃtulo 4), apresentamos uma investigaÃÃo numÃrica do desempenho de um filtro passa-banda totalmente Ãptico composto por um acoplador direcional duplo seguido de duas grades de Bragg simetricamente iguais gravadas nos seus braÃos de saÃda. Esta configuraÃÃo caracteriza um InterferÃmetro de Michelson com caracterÃsticas de um filtro add/drop. As caracterÃsticas de transmissÃo (T), taxa de extinÃÃo (XR) e âcrosstalkâ (XT) foram estudadas a partir da aplicaÃÃo de um sinal CW (onda contÃnua) na entrada do dispositivo. A teoria de modos acoplados e o mÃtodo de Runge Kutta de 4a ordem foram aplicados, respectivamente para resolver as equaÃÃes diferenciais acopladas. Este à o primeiro estudo feito considerando a nÃo linearidade do acoplador e a linearidade das grades de Bragg. O dispositivo apresenta um comportamento altamente nÃo-linear em funÃÃo do defasamento entre as amplitudes dos feixes refletidos e em funÃÃo da potÃncia de entrada. Num segundo momento (capÃtulo 5) apresentamos a propagaÃÃo e chaveamento de pulsos ultracurto (~2ps) usando um interferÃmetro de Michelson de Fibras Ãpticas. Neste estudo o desempenho do interferÃmetro à estudado como uma funÃÃo das caracterÃsticas nÃo lineares do acoplador e das grades de Bragg. Os estudos numÃricos foram feitos a partir das equaÃÃes de modos acoplados resolvidas usando o mÃtodo de Runge-Kutta de 4 ordem. As caracterÃsticas de chaveamento do pulso foram analisadas em funÃÃo da potÃncia de entrada e do defasamento aplicado em uma das grades de Bragg. As caracterÃsticas de transmissÃo (T), coeficiente de ExtinÃÃo (XR), âcrosstalkâ (XT), fator de compressÃo (FC). Utilizamos trÃs valores de potÃncia de entrada: abaixo da potÃncia critica (P0=1W), igual a potÃncia crÃtica (P0=1,73W) e acima da potÃncia crÃtica (P0=1,95W). AtravÃs deste estudo, pode-se verificar que a transmissÃo, taxa de extinÃÃo, âcrosstalkâ e fator de compressÃo dependem da potÃncia da bombeio inserida no dispositivo e da defasagem aplicada. O interferÃmetro de Michelson em fibras implementa componente de grande importÃncia para aplicaÃÃes em redes Ãpticas, como os demultiplexadores add/drop. Este dispositivo tem atraÃdo bastante interesse no campo das telecomunicaÃÃes devido a sua alta capacidade de taxas de transmissÃo. Num terceiro momento foi apresentado um estudo de simulaÃÃo numÃrica do desempenho da codificaÃÃo e decodificaÃÃo de pulsos Ãpticos curtos (ps) em sistemas OCDMA (Optical Code Division Multiple Access â acesso VIII mÃltiplo por divisÃo de cÃdigo no domÃnio Ãptico) baseado em FBG (Fiber Bragg Grating â grade de Bragg em fibra Ãptica) onde os cÃdigos sÃo inseridos atravÃs de saltos discretos na fase Ãptica (Âπ). Para geraÃÃo de pulsos codificados foram utilizados cÃdigos de Gold obtidos analiticamente. Analisamos como a inserÃÃo de cÃdigos adicionais afetam a autocorrelaÃÃo e correlaÃÃo cruzada. O interferÃmetro de Michelson inicialmente estudado no capÃtulo 4 foi utilizado para propagaÃÃo e chaveamento de sinais codificados. Baseados nas caracterÃsticas de TransmissÃo (T) e Taxa de extinÃÃo (XR) fizemos um estudo do dispositivo como multiplexador /demultiplexador add/drop na recuperaÃÃo de pulsos codificados. / This work, in addition the chapters which involves both theory and definitions, was basically divided three studies: First (chapter 4),we present a numerical investigation of the performance of a bandpass filter composed of an all-optical directional coupler, followed by two double bars Bragg recorded symmetrically equal outputs in their arms. This configuration features a Michelson interferometer with characteristics of an add/ drop filter. The transmission characteristics (T), extinction rate (XR) and "crosstalk" (XT) were studied based on the application of a CW signal (continuous wave) into the device. Theory of coupled modes and the Runge Kutta fourth order were applied respectively to solve the coupled differential equations. This is the first study considering the nonlinearity of the coupler and the linearity of Bragg gratings. The device features a highly nonlinear behavior as a function of dephasing between the amplitudes of the reflected beams and depending on the input power. In a second step (section 5), the propagation and switching of ultrashort pulse (~ 2PS) Michelson interferometer using an optical fiber. In this study the performance of the interferometer is studied as a function of the nonlinear characteristics of the coupler and Bragg gratings. The numerical studies were made from the coupled mode equations solved using the Runge-Kutta 4th order. The pulse switching characteristics were analyzed as a function of input power and applied to one dephasing Bragg gratings. The transmission characteristics (T), extinction coefficient (XR), "crosstalk" (XT), the compression factor (CF)and shape of the pulses were analyzed for different values of phase and different input powers. We use three values of input power: below the critical power (1W = P0), equal to the critical power (P0 = 1.73W) and above the critical power (P0 = 1.95W). Through this study, it is found that the transmission rate of extinction, "crosstalk" and compression factor depends on the power of the pump device inserted into the gap and applied The Michelson interferometer fiber implement major component with applications in optical networks, such as demultiplexers add/drop. This device has attracted considerable interest in the field of telecommunications due to its ability of high transmission rates. In the third place was presented a numerical simulation study of the performance of encoding and decoding of short optical pulses (ps) systems OCDMA (Optical Code Division Multiple Access based on FBG (Fiber Bragg Grating ) where codes are inserted through discrete jumps in the optical phase ( π). For generation of coded pulses were used Gold codes obtained analytically. We look at how the inclusion of additional codes affect the autocorrelation and cross correlation.The Michelson interferometer initially studied Chapters 4 was used for propagation and switching of encrypted signals. Based on the characteristics of transmission (T) and extinction rate (XR) did a study of the device as multiplexer/demultiplexer add / drop in the recovery of coded pulses.