Date of Award


Degree Type


Degree Name

Master of Engineering Science


Electrical and Computer Engineering


Prof. John. W. MacDougall


In 2008, a satellite named CASSIOPE (Cascade SmallSat and Ionospheric Polar Explorer) will be launched. The e-POP (Enhanced Polar Outflow Probe) payload on it will be used to conduct research on the ionosphere. A HF Tomography technique, which needs HF signals transmitted from ground-based transmitters and collected by the e-POP, is proposed to generate the ionospheric tomographie reconstruction images. According to the technique, the transmitters are required to transmit two pulsed adjacent frequency signals in the HF band and work synchronously with each other. A new dual-frequency transmitter has been developed for this purpose. In each transmitter, a 16-bit microcontroller can control DDS chips to generate two pulsed closely spaced frequency signals and it allows users to set up parameters through input switch panels. Several coding methods, such as Barker and Legendre, can be chosen for modulation. GPS system and Time Division Multiple Access (TDMA) scheme are applied to synchronize and accommodate transmitters in different locations. Lab and field experiments have demonstrated that the transmitter can satisfy the requirements of the HF Tomography technique for the e-POP mission. A network of three of these transmitters also operates with a CADI receiver to measure the TIDs in the ionosphere. Observation results are shown and compared with those from other researchers.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.