Software Defined Radio for GNSS Radio Frequency Interference Localization.

The use of radio direction finding techniques in order to identify and reject harmful interference has been a topic of discussion both past and present for signals in the GNSS bands. Advances in commercial off-the-shelf radio hardware have led to the development of new low-cost, compact, phase coherent receiver platforms such as the KrakenSDR from KrakenRF whose testing and characterization will be the primary focus of this paper. Although not specifically designed for GNSSs, the capabilities of this platform are well aligned with the needs of GNSSs.

Atypical presentations of intracranial dysgerminoma mimicking central nervous system inflammatory or demyelinating disease.

Objectives: The aim of this study is to report a case series of atypical presentations of intracranial dysgerminoma in which the diagnosis was delayed due to clinical and radiographic findings initially suggestive of CNS inflammatory or demyelinating diseases, such as MS.

Methods: This study is a case series detailing the history, clinical presentations, radiographic and laboratory results, and management of three patients with biopsy-proven intracranial dysgerminoma.

Results: All three patients demonstrated hyperintense lesions on MRI that were more suggestive of demyelinating or inflammatory diseases, including lesions involving the midbrain and corpus callosum.

Design and implementation of real-time software radio for anti-interference GPS/WAAS sensors.

Adaptive antenna array processing is widely known to provide significant anti-interference capabilities within a Global Navigation Satellite Systems (GNSS) receiver. A main challenge in the quest for such receiver architecture has always been the computational/processing requirements. Even more demanding would be to try and incorporate the flexibility of the Software-Defined Radio (SDR) design philosophy in such an implementation.

A real-time capable software-defined receiver using GPU for adaptive anti-jam GPS sensors.

Due to their weak received signal power, Global Positioning System (GPS) signals are vulnerable to radio frequency interference. Adaptive beam and null steering of the gain pattern of a GPS antenna array can significantly increase the resistance of GPS sensors to signal interference and jamming. Since adaptive array processing requires intensive computational power, beamsteering GPS receivers were usually implemented using hardware such as field-programmable gate arrays (FPGAs).

Sacroiliac joint vacuum phenomenon--underreported finding.

Background And Purpose: Vacuum phenomenon (VP) is commonly found in sacroiliac joints, and its significance in patients with back pain has been debated. We investigated the prevalence of sacroiliac joint vacuum phenomenon (SJVP) and the rate at which it is reported on abdominopelvic and lumbosacral spine computed tomography (CT) images by body imagers and neuroradiologists. We hypothesized that it would be more common than not and that neuroradiologists would identify it more frequently than body imagers and on spine images more commonly than abdominopelvic studies due to the search for the source of back pain in the former.

Reliable location-based services from radio navigation systems.

Loran is a radio-based navigation system originally designed for naval applications. We show that Loran-C's high-power and high repeatable accuracy are fantastic for security applications. First, we show how to derive a precise location tag--with a sensitivity of about 20 meters--that is difficult to project to an exact location.