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Item Wireless sensor network development for the purpose of measuring acceleration in snow(Montana State University - Bozeman, College of Engineering, 2023) Lesser, James Byron; Chairperson, Graduate Committee: Edward E. AdamsA WSN (Wireless Sensor Network) was developed for the purpose of measuring snow acceleration in response to loading of various types. In its current state, the WSN is composed of seven nodes (radio enabled sensors) and one controller. Two dynamic ranges, +/- 10 g and +/- 40 g, allow for user adjustment based on the required sensitivity of measurement. Acceleration data is logged simultaneously across all active nodes; data from an analog accelerometer is stored by each node on a microSD card. Data throughput limits the maximal sampling frequency to 10 kHz at 8-bit precision, or 5 kHz at 10-bit precision. Empirical investigation of GEM (Green Environmental Monopropellant) as a tool for avalanche mitigation was conducted with the first iteration of the WSN. The GEM explosive is compared with the industry standard, Pentolite; the metrics of comparison are those of overpressure, impulse per unit area, and the resulting snow acceleration. This study showed the effectiveness of the WSN as a tool for measuring snow dynamic response under explosive loading. Additionally, an ECT (Extended Column Test) instrumented with the WSN on this day elicited continued development of the WSN. A detailed look at the components of the WSN provides the physical and electrical qualities focused on the nodes intended environment - seasonal snow. Theory of operation, and a standard operating procedure, provide fundamental knowledge for the end user. Modal testing was performed to characterize the vibration response of the node. Natural frequencies are identified within the bandwidth of the accelerometer, and it is shown that these frequencies are not present in signals collected in snow under impulsive loading. Acceleration data acquired by the WSN in a series of stability tests, conducted in the lab and in the field, demonstrate the utility of the system.Item Phase alignment of asynchronous external clock controllable devices to periodic master control signal using the Periodic Event Synchronization Unit(Montana State University - Bozeman, College of Engineering, 2009) Ostrander, Charles Nicholas; Chairperson, Graduate Committee: Brock LaMeresThe Periodic Event Synchronization Unit aligns devices without the ability to be triggered by an external source. The primary function of the unit is to align the pattern trigger pulses of two pulse pattern generators which supply four inputs of a multiplexer. The pulse pattern generators lack the ability to start their code according to an external signal. When operating, the designed unit maintains a specific pattern alignment of two binary data streams of 5 gigabits per second as a multiplexer combines them into a data stream of four times the bit rate. In addition to alignment, the unit can introduce offsets of up to 50 nanoseconds to the pattern alignment which corresponds to 250 bits. The unit is designed to allow the alignment of other devices as well, requiring as input the two event signals of the same frequency which need to be aligned. In order to align the devices providing the event pulses, one of the devices must either accept an external clocking source or have the ability to frequency modulate the internal clock. In practice, the test system was able to achieve and maintain the desired signal characteristics from the output of the multiplexer. The unit's robust design is shown by providing alignment of patterns for the full operating range of the pulse pattern generators and allowing a generator pattern to be aligned to a generic event pulse. Use of multiple units allows alignment of additional devices. The development of the Periodic Event Synchronization Unit provided an inexpensive solution to creating very high bit rate signals using preexisting equipment, as no commercial products were found to accomplish the same function.