James Riordan

h-index65
2papers
15,112citations

2 Papers

1.9RONov 6, 2023
Segmentation of Drone Collision Hazards in Airborne RADAR Point Clouds Using PointNet

Hector Arroyo, Paul Kier, Dylan Angus et al.

The integration of unmanned aerial vehicles (UAVs) into shared airspace for beyond visual line of sight (BVLOS) operations presents significant challenges but holds transformative potential for sectors like transportation, construction, energy and defense. A critical prerequisite for this integration is equipping UAVs with enhanced situational awareness to ensure safe operations. Current approaches mainly target single object detection or classification, or simpler sensing outputs that offer limited perceptual understanding and lack the rapid end-to-end processing needed to convert sensor data into safety-critical insights. In contrast, our study leverages radar technology for novel end-to-end semantic segmentation of aerial point clouds to simultaneously identify multiple collision hazards. By adapting and optimizing the PointNet architecture and integrating aerial domain insights, our framework distinguishes five distinct classes: mobile drones (DJI M300 and DJI Mini) and airplanes (Ikarus C42), and static returns (ground and infrastructure) which results in enhanced situational awareness for UAVs. To our knowledge, this is the first approach addressing simultaneous identification of multiple collision threats in an aerial setting, achieving a robust 94% accuracy. This work highlights the potential of radar technology to advance situational awareness in UAVs, facilitating safe and efficient BVLOS operations.

12.1CRJan 31, 2014
Quantitative Analysis of Active Cyber Defenses Based on Temporal Platform Diversity

Kevin M. Carter, Hamed Okhravi, James Riordan

Active cyber defenses based on temporal platform diversity have been proposed as way to make systems more resistant to attacks. These defenses change the properties of the platforms in order to make attacks more complicated. Unfortunately, little work has been done on measuring the effectiveness of these defenses. In this work, we use four different approaches to quantitatively analyze these defenses; an abstract analysis studies the algebraic models of a temporal platform diversity system; a set of experiments on a test bed measures the metrics of interest for the system; a game theoretic analysis studies the impact of preferential selection of platforms and derives an optimal strategy; finally, a set of simulations evaluates the metrics of interest on the models. Our results from these approaches all agree and yet are counter-intuitive. We show that although platform diversity can mitigate some attacks, it can be detrimental for others. We also illustrate that the benefit from these systems heavily depends on their threat model and that the preferential selection of platforms can achieve better protection.