Radar Signatures of Drones Equipped With Heavy Payloads and Dynamic Payloads Generating Inertial Forces

Samiur Rahman,Duncan A Robertson,Mark A Govoni

doi:10.1109/access.2020.3042798

Samiur Rahman, Duncan A Robertson + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.3042798

Copy DOI

Abstract

Due to the availability of cheap commercial and customizable drones, the potential for using them to carry threat payloads has increased significantly. In this study, radar signatures of drones carrying simulated threat payloads have been investigated experimentally. Two different scenarios were considered: 1) drones carrying heavy payloads and 2) the dynamic response of a drone subject to inertial recoil forces which mimic the effect of a firearm attached to the drone. Experimental data for the two scenarios was collected with 24 and 94 GHz Doppler radar systems. Micro-Doppler analysis has revealed that (i) the degree of fluctuation in helicopter rotor modulation (HERM) lines in long integration spectrograms does not correlate with the presence or absence of a heavy payload and (ii) the blade flashes in fully sampled, short integration spectrograms confirm that the tip velocity and rotation rate increase with payload weight as extra thrust is required. However, in both cases, these effects are difficult to attribute exclusively to the presence of the heavy payloads as they can also be attributed to other factors affecting flight dynamics such as wind or platform maneuvers. Finally, we present what we believe to be the first measurements of a simulated recoil scenario in which distinct signatures in the bulk Doppler of the fuselage are clearly attributable to the applied recoil. Analysis shows that these signatures are consistent with the inertial forces which would be imparted by a 9 mm parabellum round fired from a Glock 22 pistol if it was attached to the drone.

Highlights

Drone technology has advanced significantly in recent years, allowing for numerous useful applications
We report on the experimental data analysis of the radar signatures of drones perturbed by a brief external force, simulating the effect of a gun attached to the drone and firing a shot
It should be noted that this conclusion differs from the results reported in [10], where a visual difference between the HERM line pattern was observed which may be due to the different type of drone used for that study

Summary

INTRODUCTION

Drone technology has advanced significantly in recent years, allowing for numerous useful applications. Our view is that realistic experimental data collection and analysis, even using simulated threat payloads, provides more realistic and valuable information than can be obtained from modelling. Simulation of such dynamic scenarios requires detailed knowledge of dynamic behavior of the drone’s flight controller but this is proprietary information of the manufacturer and is not readily accessible. This is the first report on the radar signatures of drones equipped with heavy payloads based on a large set of diverse experimental results. We report on the experimental data analysis of the radar signatures of drones perturbed by a brief external force, simulating the effect of a gun attached to the drone and firing a shot. Data was post processed in MATLAB® to analyze the return signal characteristics

HEAVY PAYLOADS

Output

PAYLOAD ATTACHED WITH A WIRE

Findings

Conclusions