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  1. Robust power detector for wideband signals among many single tone signals

    Various technologies for isolating a signal of interest from signals received contemporaneously by an antenna are described herein. A time period for which a signal of interest is present in a second signal can be identified based upon ratios of values of the second signal to the mean value of the second signal. When the ratio of the value of the second signal at a particular time to the mean of the second signal exceeds a threshold value, the signal of interest is considered to be present in the second signal.
  2. Artifact reduction within a SAR image

    The various technologies presented herein relate to reducing and/or filtering undesired artifacts in a SAR image, wherein the artifacts are generated by RF interference resulting from a communication signal being included in a radar return which also comprises radar clutter. The radar return is separated into two subapertures, a first subaperture comprising radar clutter only, and a second subaperture comprising radar clutter and the communication signal. The communication signal is extracted from the second subaperture and reapplied to the initially received radar return. Reapplication of the communication signal to the radar return enables any undesired artifacts arising from the communicationmore » signal to have their return strength reduced or minimized, while maintaining any desired radar returns in the SAR image.« less
  3. Synthetic Aperture Radar Spekle Reduction for Circular SAR Images.

    Abstract not provided.
  4. Mitigating Effects of Missing Data for SAR Coherent Images

    Missing samples within synthetic aperture radar data result in image distortions. For coherent data products, such as coherent change detection and interferometric processing, the image distortion can be devastating to these second order products, resulting in missed detections and inaccurate height maps. Earlier approaches to repair the coherent data products focus upon reconstructing the missing data samples. This study demonstrates that reconstruction is not necessary to restore the quality of the coherent data products.
  5. Replacing missing data between airborne SAR coherent image pairs

    For synthetic aperture radar systems, missing data samples can cause severe image distortion. When multiple, coherent data collections exist and the missing data samples do not overlap between collections, there exists the possibility of replacing data samples between collections. For airborne radar, the known and unknown motion of the aircraft prevents direct data sample replacement to repair image features. Finally, this paper presents a method to calculate the necessary phase corrections to enable data sample replacement using only the collected radar data.
  6. Interference Mitigation Effects on Synthetic Aperture Radar Coherent Data Products

    For synthetic aperture radars radio frequency interference from sources external to the radar system and techniques to mitigate the interference can degrade the quality of the image products. Usually the radar system designer will try to balance the amount of mitigation for an acceptable amount of interference to optimize the image quality. This dissertation examines the effect of interference mitigation upon coherent data products of fine resolution, high frequency synthetic aperture radars using stretch processing. Novel interference mitigation techniques are introduced that operate on single or multiple apertures of data that increase average coherence compared to existing techniques. New metricsmore » are applied to evaluate multiple mitigation techniques for image quality and average coherence. The underlying mechanism for interference mitigation techniques that affect coherence is revealed.« less
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"Musgrove, Cameron"

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