Radar Meteor Trail Detection and Classification
Open Access
- Author:
- Zhao, Siming
- Graduate Program:
- Electrical Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 30, 2010
- Committee Members:
- Julio Urbina, Thesis Advisor/Co-Advisor
Julio Urbina, Thesis Advisor/Co-Advisor - Keywords:
- detection
meteor trails - Abstract:
- Meteor data are continuously collected by radars operating year round. Analyzing this fast growing, large dataset requires efficient and reliable detection routines. Currently, most meteor echo detection routines automatically detect underdense meteor trails but overlook overdense meteor trails and usually fail on non-specular trails. In this thesis, a multilayer radar detection algorithm is proposed to detect and correctly identify multiple types of meteor trail reflections. The complete process consists of two steps. The first step is based on the time-frequency waveform detector developed by Kang and Palo [2007]. We started by selecting low signal to noise ratio in order to detect all types of radar signals; however, a high probability of false alarm was produced. In the second step, several features from the detected echoes in step one are extracted and a support vector machine (SVM) classifier is constructed to further classify these echoes. The algorithm was tested using data from a 50-MHz radar stationed near Salinas Puerto Rico on April 5, 1998. A total of 271 detected echoes were labeled as underdense, overdense, non-specular, other ionospheric echoes, and noise. We used 208 echoes as training and 63 echoes as testing samples. This technique successfully classified about 85% of the testing samples. Details concerning implementation, feature extraction, and data visualization are presented in this thesis. Lastly, the effects of the Earth’s magnetic B field on the detection of meteor trails are analyzed. Our data show that non-specular trails were exclusively detected when the radar k vector was oriented perpendicular to B, which is consistent with recent work reported by others. We also found that more specular trails were detected with the radar beam perpendicular to B than the beam pointed off-perpendicular to B. This may indicate that the development of turbulence enhances the specular reflection radar cross-section or relaxes the specular criterion to larger angles.