Software-defined radio is a rapidly developing field that driving the development of and innovation in communications technology, promises to significantly impact all sectors. Entities these SDR systems require trained workforce has been prepared with mindset, knowledge, skills, tools required address both system (breadth) technical (depth) aspects systems. Developing SDRs necessarily involves collection disciplines including, but not limited to, electromagnetics, radio-frequency...

Collective cancer invasion exhibits a hierarchical structure characterized by leader-follower organization. Dynamic gene expression analysis of invading cells using nanobiosensors within 3D microenvironments provides valuable means to explore the regulation leader during collective invasion. Nonetheless, time-lapse, multimodal images that capture intricacies complex structures and profiles in tumor spheroids poses significant technological challenge. Here, we present computer vision-based...

We report VHF radar observations of the southern high‐latitude mesopause region using wind profilers that were installed recently on King George Island, Antarctica, and Ushuaia, Argentina. Briefly, our observations, which made during January February 1993, show almost no evidence so‐called polar mesosphere summer echoes, or PMSE. Since these echoes are a predominant feature northern in summer, their absence hemisphere is both surprising intriguing. In this paper we present demonstrating...

Abstract In this paper, a novel design and implementation of software‐defined high‐frequency ionospheric radar, the Penn State Ionospheric Radar Imager (PIRI), is described. Furthermore, preliminary results produced by system (located at 40.71° N, 77.97° W) are presented. PIRI designed to be modest low‐cost radar system, which composed mostly commercial‐off‐the‐shelf products utilizing open‐source software perform pulse generation, coding, downconversion, data acquisition, signal processing....

ABSTRACT This work presents the result of sporadic meteor radiant density distribution using Arecibo 430 MHz incoherent scatter radar (ISR) located in Puerto Rico for first time. Although numerous studies have been carried out ISR, meteoroid has remained a mystery as cannot measure vector velocity. A numerical orbital simulation algorithm dynamic programming and stochastic gradient descent is designed to solve corresponding speed distributions meteors observed at Arecibo. The data set...

A 50 MHz radar interferometer was used near Salinas, Puerto Rico, to probe the meter‐scale E‐region plasma density irregularities during two campaigns conducted in 1998. During February–April period echoing layers were primarily observed between 90 and 100 km heights. The typically thin (∼1 km) unstructured, although several cases short (∼90 s) layer oscillations observed. June–July echoes showed more varied characteristics. In addition low altitude layers, quasi‐periodic structures with...

We report a surprising absence of PMSE (Polar Mesospheric Summer Echoes) in VHF radar observations the southern summer high‐latitude mesosphere. Our cover about twenty days during January‐February, 1993, from King George Island, Antarctica.

Nonclassical radar meteor echoes or range spread trail (RSTEs), lasting from tens of seconds to over 15 min, have been a subject considerable interest and speculation in the community ever since they were first observed 1940s. Using data collected Jicamarca Radio Observatory 50 MHz VHF June 2006, we find that many properties RSTEs can be explained largely radio science perspective. On statistical basis, duration >15 s are exclusively scatterers k ⊥ B ( = wave number; geomagnetic field)...

A technique using satellite-link signal attenuation measurements for estimating rainfall accumulation along the link path is evaluated. Power law relationships between rate and R are used to estimate with a satellite operating at Ku-band (12.3 GHz). Polarimetric radar obtained from National Weather Service Surveillance Radar-1988 Doppler system near State College, Pennsylvania, utilized provide comparison of estimates. tipping-bucket rain gauge, colocated receiver, also comparison. method...

Resonance Lidar observations of neutral sodium and VHF coherent scatter radar field‐aligned 3‐meter irregularities were obtained during the Coqui II rocket campaign in Puerto Rico. The Lidar, a facility instrument at Arecibo Observatory (18.3°N, 66.8°W), University Illinois Radar, located near Salinas on south island, both monitored volumes where uplegs nominal trajectories intersected E‐region. Observatory's Incoherent Scatter Radar was also used to characterize plasma layers. Preliminary...

We report the first incoherent scatter radar observations—made at Arecibo Observatory—of remarkable bottom‐side (<280 km) F‐region sheet‐like plasma structures with horizontal/vertical‐scales of ≲1 km. These are an apparent manifestation spread‐F, appear to give rise VHF coherent (FAI) scattering, and clearly electrodynamic in origin involving a form Perkins spread‐F instability process presence relatively large E‐fields horizontal gradients. The net appears be associated downwelling...

An intense mid‐latitude spread‐ F event occurred over Puerto Rico during the night of February 17, 1998. Simultaneous observations were made with Cornell University Portable Radar Interferometer (CUPRI) located near Isabela, PR, Illinois VHF radar at Salinas, GPS receivers Isabela and St. Croix, measuring total electron content, Arecibo incoherent scatter radar, All‐Sky imager Observatory. This was first time that such a broad range complementary instrumentation captured space weather event....

We present a machine-learning approach to detect and analyze meteor echoes (MADAME), which is radar data processing workflow featuring advanced techniques using both supervised unsupervised learning. Our results demonstrate that YOLOv4, convolutional neural network (CNN)-based one-stage object detection model, performs remarkably well in detecting identifying head trail within processed signals. The detector can identify more than 80 per minute the testing obtained from Jicamarca high power...

In this paper, a bistatic passive radar receiver system named “Coherent‐scatter Atmospheric Passive Radar Imager (CAPRI)” is described. It primarily designed to study the dynamics of upper atmosphere by utilizing “transmitters opportunity” as RF target illuminators. CAPRI constructed using open source software‐defined radio toolkit, GNU Radio, meet signal processing requirements in combination with hardware, Universal Software Radio Peripheral 2, for data acquisition. The resultant highly...

Relatively little progress has been made in the study of equatorial Sporadic‐E when compared to mid‐latitude Sporadic‐E. Indeed, it is unclear if observed at all near geomagnetic equator using any technique other than ionosonde. In particular, there have no reports Jicamarca Radio Observatory (JRO) 50 MHz radar. The overwhelming—in SNR terms—presence nearly ubiquitous Equatorial Electrojet (EEJ) likely reason not reported JRO as well similar radars equator. We present here what we believe be...

The attenuation of a commercial satellite link signal at Ku-band is used for estimating rainfall rate along the path. Comparisons with accumulations obtained using simultaneous radar measurements same path show good agreement. This method can potentially be to complement other accumulation and rain gauges in urban settings areas complex terrain.

Multi‐static, common volume radar (MSCVR) observations have long been considered necessary for meteor observations, especially the study of Range Spread Trail Echoes (RSTE). We present preliminary results ‐ in form a case from first MSCVR that were carried out at Jicamarca Radar Observatory (JRO) June 2007. A second antenna array, similar sensitivity to single JRO receive module, was constructed and operated Carapongo, approximately 5 kilometers geomagnetically south JRO. The main array used...

Abstract. We present the first global simulations on occurrence of meteor trail plasma irregularities. These results seek to answer following questions: when a meteoroid disintegrates in atmosphere, will resulting become turbulent? What are factors influencing development turbulence? and how do these trails vary scale? Understanding turbulence is important because turbulent visible as non-specular coherent radars. Turbulence also influences evolution specular radar trails; this fact for...

Passive radar systems operate by employing cooperative or noncooperative radio signals in the environment order to sense remote targets. This particular feature of passive provides unique opportunities expand coverage map conventional radars. In using systems, any undesirable obstacle between transmitted signal and path desirable target can cause obliteration on source destroy its key correlative properties. The equatorial electrojet (EEJ) have unfavorable effects operation prospective which...

Polar research using ice-penetrating radars will benefit from the development of smaller and more flexible systems. In this paper, we present progression for a series compact frequency-reconfigurable based on software-defined radio (SDR) technology platforms. The Ice Radar developed consists three systems, each different SDR platform that afforded additional capability as progressed. Detailed descriptions system structure performance are provided ice radar. We laboratory measurements to...

In this article, we present the development and integration of an existing cost-effective, open-source software-defined radio (SDR) receiver into a complete, pulsed-radar system used to study meteor reflections that ablate in Earth's atmosphere. The use SDR technology radar applications is not, itself, new concept, but details regarding construction back-end processing, formatting, storage have not been widely discussed. More specifically, systems, general, are provide communication link,...