IEEE - Aerospace and Electronic Systems - February 2020 - 3

In This Issue -Technically
INTERFERENCE AND INTRUSION IN WIRELESS SENSOR NETWORKS
Wireless sensor network (WSN) systems for safety-critical, space and Internet of Things applications have recently begun to adopt
open standards and commercial-off-the-shelf equipment, and persistently face challenges of malicious intrusion and spectrum
coexistence. These threats are explored through Monte-Carlo simulation and benchtop testing, including matched protocol interference and sophisticated, interactive intrusion attacks. The need for expanding intrusion detection via a more holistic approach,
whilst simultaneously improving WSN security, is illustrated. Discussions on WSN security, vulnerabilities, and attacks are also
provided.

COVERAGE MISSION FOR UAVS USING DIFFERENTIAL EVOLUTION AND FAST MARCHING SQUARE
METHODS
This research presents a novel approach for missions of coverage path planning (CPP) carried out by unmanned aerial
vehicles (UAVs) in a three-dimensional environment. These missions are focused on path planning to cover a certain area in
an environment in order to carry out tracking, search, or rescue tasks. The methodology followed uses an optimization process based on the differential evolution (DE) algorithm in combination with the Fast Marching Square (FM2) planner. The
DE algorithm evaluates a cost function to determine what the zigzag path with the minimum cost is, according to the steering
angle of the zigzag bands (a). This optimization process allows achieving the most optimal zigzag path in terms of distance
traveled by the UAV to cover the whole area. Then, the FM2 method is applied to generate the final path according to the
steering angle of the zigzag bands resulting from the DE algorithm. The approach generates a feasible path free from
obstacles, keeping a fixed altitude flight over the ground. The flight level, smoothness, and safety of the path can be modified
by two adjustment parameters included in our approach. Simulated experiments carried out in this work demonstrate that the
proposed approach generates the most optimal zigzag path in terms of distance, safety, and smoothness to cover a certain
whole area, keeping a determined flight level with successful results.

GNURADAR: AN OPEN-SOURCE SOFTWARE-DEFINED RADAR RECEIVER PLATFORM
In this article, we present the development and integration of an existing cost-effective, open-source softwaredefined radio (SDR)
receiver into a complete, pulsed-radar system used to study meteor reflections that ablate in the Earth's atmosphere. The use of
SDR technology in radar applications is not, in itself, a new concept, but details regarding construction of back-end processing,
formatting, and storage have not been widely discussed. More specifically, SDR systems, in general, are used to provide a
communication link, meaning that precise time of arrival and signal levels are not of primary importance, but these parameters
are critical in a radar system. This article addresses in detail methods used to redesign an existing, open-source receiver into a
pulse-synchronized radar system for use by anyone interested in cost-effective radar data acquisition solutions. Additionally, we
provide test data from an experimental observation to validate operation and performance of the resulting system.

A DOPPLER CORRECTING SOFTWARE DEFINED RADIO RECEIVER DESIGN FOR SATELLITE
COMMUNICATIONS
We present a flexible software defined radio (SDR) receiver design for the reception and demodulation of satellite signals. The
proposed SDR performs an online Doppler search, as well as a code-rate and code-phase search online. The use of graphics
processing units (GPUs) allows the radio to compensate Doppler offsets and achieve symbol synchronization in real time. This
eliminates the need for a priori information on the satellites position and velocity to perform Doppler compensation on the
downlink. To successfully utilize the enhanced computational power of graphics processing unit s (GPUs) and achieve real-time
performance, we utilize acausal batch based signal processing, which allows for the use of fast convolution algorithms. These
can efficiently be parallalized and run on GPUs. The Doppler search and demodulation is done by using matched filters. This
allows one to adapt the demodulator to work for many modulation schemes by merely changing the set of filters. The demodulator
itself essentially works as a batched correlation receiver. Additionally, the proposed SDR can decode signals from multiple
antennas that are located at geographically spread ground stations simultaneously. The decoded bits are compared using soft
decisions. This can greatly increase the rejection of local burst interference as well as polarized interference and tracking signals
that rotate in polarization.

FEBRUARY 2020

IEEE A&E SYSTEMS MAGAZINE

IEEE - Aerospace and Electronic Systems - February 2020

Table of Contents for the Digital Edition of IEEE - Aerospace and Electronic Systems - February 2020