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Air Traffic Simulation with HackRF One
Mikan, Lukáš ; Dvořák, Vojtěch (oponent) ; Šťáva, Martin (vedoucí práce)
This work deals with air traffic simulation in the context of a multilateration surveillance system. The technique of multilateration calculates aircraft position at the intersection of hyperboloids, obtained from the differences in time of arrival of transponder messages to multiple receivers at known coordinates. By substituting an SDR module for each receiving antenna, air traffic can be simulated with the use of made-up ADS-B messages which get sent to the various antenna ports with proper timing. This thesis uses the HackRF One SDR that had both its hardware and firmware modified in order to achieve tightly synchronized transmissions from potentially any number of interconnected HackRF units. The modifications described herein ensure an identical sampling clock, both frequency- and phase-wise, across all units, as well as simultaneous triggering of transmissions. In the second part of the thesis, an algorithmic solution is presented for assembling fictional air scenarios with arbitrary number of flights and receiving stations. The output is a set of data streams suitable to be transmitted through synchronized HackRF's. Each stream represents a specific vantage point, a specific antenna, and contains precisely timed ADS-B messages, encoded using pulse-position modulation and converted into IQ samples. The complete solution can be used to validate the functioning of a real multilateration system, such as the MSS made by ERA, a.s.
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Ultrasonic flow measurement
Mikan, Lukáš ; Boušek, Jaroslav (oponent) ; Šteffan, Pavel (vedoucí práce)
This work deals with ultrasonic flow meters which represent a very viable alternative to conventional mechanical solutions. The first part gives an overview of the gas metering industry, different types of gas meters are presented with emphasis on how they compare to the ultrasonic approach. Then, the physics that go into ultrasonic flow measurement are explained. In particular, the Transit Time method is explored which utilizes the time of flight of an ultrasonic signal to calculate the velocity of gas in a pipe. In the second part, a simple functional model is implemented with three ultrasonic paths. This model can measure gas velocity, flow rate, and accumulated volume. It emulates the industry-standard pulse output in order to communicate the volume. The technical solution is based on AS6040 which is a dedicated SoC for ultrasonic flow meters of the Transit Time kind. Presented are the various features of AS6040, the algorithmic measurement system, and key issues faced during development. The functional model is then brought to a sonic nozzle test bench. The third part of this work analyzes the obtained data.
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Air Traffic Simulation with HackRF One
Mikan, Lukáš ; Dvořák, Vojtěch (oponent) ; Šťáva, Martin (vedoucí práce)
This work deals with air traffic simulation in the context of a multilateration surveillance system. The technique of multilateration calculates aircraft position at the intersection of hyperboloids, obtained from the differences in time of arrival of transponder messages to multiple receivers at known coordinates. By substituting an SDR module for each receiving antenna, air traffic can be simulated with the use of made-up ADS-B messages which get sent to the various antenna ports with proper timing. This thesis uses the HackRF One SDR that had both its hardware and firmware modified in order to achieve tightly synchronized transmissions from potentially any number of interconnected HackRF units. The modifications described herein ensure an identical sampling clock, both frequency- and phase-wise, across all units, as well as simultaneous triggering of transmissions. In the second part of the thesis, an algorithmic solution is presented for assembling fictional air scenarios with arbitrary number of flights and receiving stations. The output is a set of data streams suitable to be transmitted through synchronized HackRF's. Each stream represents a specific vantage point, a specific antenna, and contains precisely timed ADS-B messages, encoded using pulse-position modulation and converted into IQ samples. The complete solution can be used to validate the functioning of a real multilateration system, such as the MSS made by ERA, a.s.
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