2,767 research outputs found
RADAR Based Collision Avoidance for Unmanned Aircraft Systems
Unmanned Aircraft Systems (UAS) have become increasingly prevalent and will represent an increasing percentage of all aviation. These unmanned aircraft are available in a wide range of sizes and capabilities and can be used for a multitude of civilian and military applications. However, as the number of UAS increases so does the risk of mid-air collisions involving unmanned aircraft. This dissertation aims present one possible solution for addressing the mid-air collision problem in addition to increasing the levels of autonomy of UAS beyond waypoint navigation to include preemptive sensor-based collision avoidance. The presented research goes beyond the current state of the art by demonstrating the feasibility and providing an example of a scalable, self-contained, RADAR-based, collision avoidance system. The technology described herein can be made suitable for use on a miniature (Maximum Takeoff Weight \u3c 10kg) UAS platform. This is of paramount importance as the miniature UAS field has the lowest barriers to entry (acquisition and operating costs) and consequently represents the most rapidly increasing class of UAS
How Well Sensing Integrates with Communications in MmWave Wi-Fi?
The development of integrated sensing and communication (ISAC) systems has
recently gained interest for its ability to offer a variety of services
including resources sharing and new applications, for example, localization,
tracking, and health care related. While the sensing capabilities are offered
through many technologies, rending to their wide deployments and the high
frequency spectrum they provide and high range resolution, its accessibility
through the Wi-Fi networks IEEE 802.11ad and 802.11ay has been getting the
interest of research and industry. Even though there is a dedicated
standardization body, namely the 802.11bf task group, working on enhancing the
Wi-Fi sensing performance, investigations are needed to evaluate the
effectiveness of various sensing techniques. In this project, we, in addition
to surveying related literature, we evaluate the sensing performance of the
millimeter wave (mmWave) Wi-Fi systems by simulating a scenario of a human
target using Matlab simulation tools. In this analysis, we processed channel
estimation data using the short time Fourier transform (STFT). Furthermore,
using a channel variation threshold method, we evaluated the performance while
reducing feedback. Our findings indicate that using STFT window overlap can
provide good tracking results, and that the reduction in feedback measurements
using 0.05 and 0.1 threshold levels reduces feedback measurements by 48% and
77%, respectively, without significantly degrading performance.Comment: arXiv admin note: substantial text overlap with arXiv:2207.04859 by
other author
Examples of current radar technology and applications, chapter 5, part B
Basic principles and tradeoff considerations for SLAR are summarized. There are two fundamental types of SLAR sensors available to the remote sensing user: real aperture and synthetic aperture. The primary difference between the two types is that a synthetic aperture system is capable of significant improvements in target resolution but requires equally significant added complexity and cost. The advantages of real aperture SLAR include long range coverage, all-weather operation, in-flight processing and image viewing, and lower cost. The fundamental limitation of the real aperture approach is target resolution. Synthetic aperture processing is the most practical approach for remote sensing problems that require resolution higher than 30 to 40 m
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