Neural net based pattern recognition on the graph search machine. - Helen Na; Stephen C. Glinski (ICASSP, 1988)

Resolution analysis of tomographic reconstruction of electron density profiles in the Ionosphere. - Helen Na; Hua Lee (Int. J. Imaging Syst. Technol., 1990)

Orthogonal decomposition technique for ionospheric tomography. - Helen Na; Hua Lee (Int. J. Imaging Syst. Technol., 1991)

Fundamental analysis of the tomographic imaging system for reconstructing ionospheric distributions - Helen Na (1991)

Analysis of fundamental resolution limit of ionospheric tomography. - Helen Na; Hua Lee (ICASSP, 1992)

A Space-Frequency Algorithm for Limited Anlge Tomography. - Helen Na; Chaitali Biswas (ICIP (2), 1994)

High Resolution Ionospheric Tomography Through Orthogonal Decomposition. - Eric Sutton; Helen Na (ICIP (2), 1994)

Resolution analysis of ionospheric tomography systems. - Helen Na; Eric Sutton (Int. J. Imaging Syst. Technol., 1994)

Orthogonal decomposition framework for ionospheric tomography algorithms. - Eric Sutton; Helen Na (Int. J. Imaging Syst. Technol., 1994)

Measures of information content for computerized ionospheric tomography. - B. Hall; Helen Na (ICIP, 1995)

A new iterative algorithm for ionospheric tomography. - Eric Sutton; Helen Na (ICIP, 1995)

Static tomographic reconstruction of the time varying ionosphere. - Eric Sutton; Helen Na (ICIP (3), 1996)

A block iterative algorithm for tomographic reconstruction of ionospheric electron density. - Eric Sutton; Helen Na (Int. J. Imaging Syst. Technol., 1996)

Limited Angle Tomography Using Volumetric Constraints. - Chaitali Biswas; Helen Na (ICIP (1), 1997)

Time-varying reconstruction of the ionosphere. 1. The algorithm. - Eric Sutton; Helen Na (Int. J. Imaging Syst. Technol., 1998)

Time-varying reconstruction of the ionosphere. 2. Data source analysis. - Eric Sutton; Helen Na (Int. J. Imaging Syst. Technol., 1998)