Effect of Instrument Frequency Uncertainty on Wideband Microwave Synthetic Aperture Radar Images

Citation data:

IEEE Transactions on Instrumentation and Measurement, ISSN: 0018-9456, Vol: 68, Issue: 1, Page: 151-159

Publication Year:
2018
Usage 2
Abstract Views 2
Repository URL:
http://scholarsmine.mst.edu/ele_comeng_facwork/3509
DOI:
10.1109/tim.2018.2834098
Author(s):
Horst, Matthew Jared; Ghasr, Mohammad Tayeb Ahmad; Zoughi, R.
Publisher(s):
Institute of Electrical and Electronics Engineers (IEEE)
Tags:
Physics and Astronomy; Engineering; Distortion; Frequency Measurement; Frequency Uncertainty; Image Distortion; Instrumentation Error; Measurement Uncertainty; Microwave Imaging; Microwave Measurement; Nondestructive Testing (NDT); Synthetic Aperture Radar (SAR) Imaging.; Uncertainty; Distortion; Frequency Measurement; Frequency Uncertainty; Image Distortion; Instrumentation Error; Measurement Uncertainty; Microwave Imaging; Microwave Measurement; Nondestructive Testing (NDT); Synthetic Aperture Radar (SAR) Imaging.; Uncertainty; Electrical and Computer Engineering
article description
In this paper, we investigate the effect of frequency uncertainty in signals generated or measured by a microwave instrument on the resulting synthetic aperture radar (SAR) images, particularly for nondestructive testing (NDT) applications. Wideband SAR imaging systems measure reflections from a target by irradiating it with locally generated signals that can potentially have some level of frequency uncertainty. Quantifying this frequency uncertainty provides the user with a realistic and expected level of image distortion which may manifest itself as blurring, noise artifacts, etc. In this paper, we show that as uncertainty in the actual frequency value increases, the level of image distortions increases predominantly for distant targets. This is an important fact for NDT applications since the imaged object is commonly close to the imaging system. In addition, these imaging system usually have a limited ``aperture'' size, which makes target distance an important consideration. For complex targets, we show how frequency uncertainty-based image distortions can dominate features in an image depending on the reflected signal amplitude from the target. We also show that in real imaging systems, the statistical distribution of frequency uncertainty combined with practical, near-target ranges (distances) produce nondiscernible image distortions.