This chapter investigates more carefully this step of image formation from digitized focused k-space data and discusses techniques for obtaining imagery with improved resolution and reduced sidelobes compared with imagery obtained simply using the weighted FT. The authors also introduce two other definitions: Signal processing, which is the processing of the k-space signal to form an image; Image processing, which is additional processing performed on the image to improve the contrast, resolution, and so on.

Chapter Contents:

• 8.1 Digital Image Formation (Signal Processing)
• 8.1.1 Real and Complex Imagery
• 8.1.2 Discrete Fourier Transform
• 8.1.3 Zero Padding
• 8.1.4 Formation of a Digital SAR/ISAR Image
• 8.1.5 Point-Spread Function
• 8.1.6 Range Window
• 8.2 Digital Image Enhancement (Image Processing)
• 8.2.1 Introduction to Superresolution and Sidelobe Reduction Techniques
• 8.2.2 DFT (FFT) Processing
• 8.2.3 Periodogram
• 8.2.4 Minimum-Variance Method
• 8.2.5 High-Definition Vector Imaging
• 8.2.6 Adaptive Sidelobe Reduction
• 8.2.7 Spatially Variant Apodization
• 8.2.8 Super-SVA
• 8.2.9 Other Spectral Estimation Techniques and Applications
• 8.2.10 Example Results
• 8.2.11 Comment on Spectral-Estimation Techniques
• References
• Problems

Inspec keywords: image resolution; radar imaging; synthetic aperture radar

Other keywords: improved resolution; reduced sidelobes; image processing; signal processing; k-space signal; digitized focused k-space data; SAR/ISAR digital imagery; image formation

Subjects: Optical, image and video signal processing; Signal processing and detection; Radar equipment, systems and applications