Pulse Coding for ionospheric radar

CADI (Canadian Advanced Digital Ionosonde) is an active radar, which is used to probe the structure and motion of the ionosphere, such as virtual height, drift velocity, angle of arrival, echo intensity, etc. It is mainly composed of a control platform (like a personal computer PC), the plug-in DDS (Direct Digital Synthesizer) board and receiver board, the power amplifier, and the antennas. This project is aimed to improve the Signal-to-Noise Ratio (SNR) of the CADI system and implement low power transmission using long sequence pulse coding. The main idea of the coding technique is to make use of the good correlation properties of certain codes to implement better Signal-to-Noise Ratio. A 1019-bit Legendre sequence is going to be used in the CADI system. For the Barker 13, the SNR is improved around 11 dB, but the SNR of a 1019-bit Legendre sequence is improved about 30dB. Some experiments prove this theory. The peak transmitted power can be lowered down to 6W or even 1W using this technique. In this thesis, the first two chapters give the introduction of the ionosphere and the basic concept and principal of pulse radar. In the Chapter 3, the CADI system is described in brief. The following chapter introduces the pulse coding. The Legendre sequence and the m-sequence are particularly mentioned in this chapter. Their correlation results and ambiguity function results are presented. Chapter 5 and chapter 6 mainly illustrate the implementation of the system and the field experimental results. Finally, the discussion and conclusion are given regarding to the experimental results.

Name thesis:degree_name

Master of Engineering Science

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Grantor dc:publisher

The University of Western Ontario

Year dc:date.issued

2003

Author dc:creator

• Huang, Jing

Advisor dc:contributor.advisor

• MacDougall, John W.

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14721/39039

OAI identifier oai:identifier

oai:uwo.scholaris.ca:20.500.14721/39039