Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Sea-surface small target detection is always a difficult problem in high-resolution maritime ubiquitous radars for complex characteristics of sea clutter, weak target returns, and diversity of targets. Multiple features extracted from radar returns in different domains have ability but not enough to solely distinguish radar returns with target from sea clutter. Joint exploitation of multiple features

An analytic model for calculating the instantaneous and average orbital power available to a satellite in a circular low Earth orbit is presented. By accounting for the effects of angle of solar incidence and eclipsing, for both stabilized and tumbling satellites, this model allows for fast, simple, accurate calculations of available power without the use of complex, often expensive, numerical simulation

The adaptive matched filter (AMF) uses a number of training samples observed by the radar to estimate the unknown disturbance covariance matrix of a cell under test. In general, as the number of homogeneous training samples increases, the detection performance of the AMF improves up to a theoretical limit (defined by the performance of a matched filter detector where the disturbance covariance is known)

BepiColombo's Mercury orbiter radio science experiment (MORE) was conceived to enable extremely accurate radio tracking measurements of the Mercury Planetary Orbiter to precisely determine the gravity field and the rotational state of Mercury, and to test theories of gravitation (e.g., Einstein's theory of general relativity). The design accuracy of the radio tracking data was 0.004 mm/s (at 1000 s

Polarimetric diversity has been recently shown to significantly improve the target detection performance in the passive radar systems if properly exploited to mitigate the competing interference. An adaptive processing scheme is presented in this article, leveraging the information conveyed using multipolarized receiving antennas and modeling the disturbance as a multichannel autoregressive process

Inverse synthetic aperture radar (ISAR) is capable of producing 2-D and 3-D images of non-cooperative targets. Compared with 2-D ISAR images, 3-D ISAR reconstructions can provide not only range and cross-range information, but also the information about the third dimension of the target, which is of great significance for automatic target recognition (ATR) and even more specifically to the case of

This article presents an optimal guidance approach for unmanned aerial vehicle navigation between two given points in 3D considering the wind influence. The proposed cost function to be minimized involves the weighting of the travel time and the control energy. An analytical expression is derived for the optimal cost yielding a fourth-order polynomial, whose positive real roots correspond to the optimal

This article presents formulas to calculate the source depth based on the arrival angle and time delay between the direct and surface-refracted arrivals measured in deep water from a broadband signal. Using the formulas, the data autocorrelation is transformed to a correlation sequence as a function of assumed source depth, which can be simply averaged over a long time to estimate the source depth

Analyzing radar signals is an important task in operating electronic support measure systems. The received signals in the real electromagnetic environment often originate from multiple emitters and must be separated for further processing. Pulses from important target emitters with known parameters should be picked out first. To solve the problem, time-of-arrival (TOA) deinterleaving may be performed

In order to address the problem of 3-D localization of an underwater target using a 2-D active sonar with unknown oceanographic factors in a multipath environment with heavy clutter, a novel iterative framework based on Maximum Likelihood Probabilistic Data Association (ML-PDA), which considers ocean sound speed profile (SSP) uncertainty and utilizes multiple detections to realize 3-D position estimation

In this article, we propose a new algorithm that designs a transmit beampattern for multiple-input multiple-output (MIMO) radar considering coexistence with other wireless systems. This design process is conducted by minimizing the deviation of the generated beampattern (which in turn is a function of the transmit waveform) against an idealized one while enforcing the waveform elements to be constant

Various correlation-based receivers have been proposed in passive bistatic and active monostatic radar exploiting orthogonal frequency-division multiplexing communications signals, but too little has been dedicated to establishing their relations and advantages over each other. Accordingly, this article provides an analytical comparison of the common filters in such waveform sharing scenarios, along

An adaptive relative pose controller for docking ports of two uncertain spacecraft in autonomous rendezvous and docking is developed. A novel relative translational and rotational model represented in the chaser body-fixed frame is derived first based on the classical Newton–Euler equations. Based on the proposed model, a six-degrees-of-freedom adaptive control law is presented based on norm-wise estimations

The effect of jammer on radar or jamming performance has been and is being assessed on the basis of range reduction where consistency in tracking target ability is more important than range reduction in a tracking radar. A new criterion known as relative radar functionality destruction time is defined and introduced as the relative of functionality destruction time of radar to one period of jammer

In this article, a guidance law with impact angle constraint is developed using the state-dependent Riccati equation (SDRE) technique. First, the nonlinear guidance dynamics consisting of line-of-sight (LOS) angle rate and error is formulated under a planar engagement scenario. After the state-dependent coefficient parameterization, a nonlinear regulator problem is formed to concurrently zero LOS angle

This article proposes a control method for space manipulators rendezvousing with and capturing a target, involving concurrent operation of an optimal and a coordinated controller. The optimal controller drives the whole system to rendezvous with the target, which saves onboard fuel and satisfies obstacle avoidance constraint and base spacecraft thrust limits. The optimal control problem is solved using

This article investigates the problem of distributed fixed-time attitude consensus control for multiple spacecraft when only a subset of spacecraft has access to a common reference attitude and angular velocity. Two fixed-time sliding-mode observers are proposed to estimate the reference attitude and angular velocity in fixed time, respectively. Based on estimates of the reference attitude and angular

In order to handle increasing demand in air transportation, high-level automation support seems inevitable. This article presents an optimization-based autonomous air traffic control (ATC) system and the determination of airspace capacity with respect to the proposed system. We model aircraft dynamics and guidance procedures for simulation of aircraft motion and trajectory prediction. The predicted

This article studies the air-to-ground ultra-wideband channel through propagation measurements between 3.1 to 4.8 GHz using unmanned-aerial-vehicles (UAVs). Different line-of-sight (LOS) and obstructed-LOS scenarios and two antenna orientations were used in the experiments. Multipath channel statistics for different propagation scenarios were obtained, and the Saleh–Valenzuela model was found to provide

An adaptive ranging technique for maintaining high-accuracy ranging between nodes in coherent distributed antenna arrays is presented. Coherent distributed antenna arrays are networks of wireless systems coordinated coherently at the level of the wavelength of the wireless signal. Enabling coherent operation between separate mobile nodes for active and passive microwave remote sensing requires accurate

The solar differential rotation results in different velocities on the solar disk. The Doppler velocities of different points on the solar disk observed by the spacecraft are also different, which are functions of the current position of the spacecraft. Thus, using the velocities’ information or their differences, the position of the spacecraft can be estimated. The advantage of velocity difference

We consider a multiple-input multiple-output (MIMO) radar that works through one-bit sampling of received radar echoes. The application of one-bit sampling significantly reduces the hardware cost, energy consumption, and systematic complexity, but it also poses serious challenges to extracting highly accurate target information from one-bit quantized data. In this article, we propose a maximum likelihood

Presents the table of contents for this issue of the publication.

Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Received signal strength (RSS)-based techniques are promising for location estimation because of low cost and easy implementation. RSS measurements can be used to determine the location of a receiver, given the positions of multiple emitters. In addition, RSS measurements at receivers with known positions can be used to determine the location of an emitter. This article investigates both 3-D receiver

Frequency hopping (FH) communications are widely used in Satcom systems. The latest FH systems have exceeded 3 GHz with hop rates up to 100 000 hops/s. Traditional spectrum sensing systems hardly monitor such signals. Modulated wideband converter (MWC) is an emerging compressive sampling structure applied to sample multiband signals. This article analyses the effects of the nonlinearity of analog devices

In the detection theory framework, it is customary to assign a bound to the false alarm probability and to attempt to maximize the detection probability subject to this constraint. In the problem of moving target detection in passive radar with a noisy reference channel, we formulate a detection problem as a composite hypothesis-testing problem and solve it with the likelihood ratio test (LRT) principle

When working at extremely high altitude, aerodynamic surfaces of air-breathing hypersonic vehicles (AHVs) may not provide sufficient control authority. To remedy this shortage, we consider AHVs equipped with the auxiliary reaction control system (RCS), which utilize a set of control jets to compensate for ineffective aerodynamic surfaces. A novel longitudinal compound control is proposed to generate

This article presents the Spacecraft Pose Network (SPN), the first neural network-based method for on-board estimation of the pose, i.e., the relative position and attitude, of a known noncooperative spacecraft using monocular vision. In contrast to other state-of-the-art pose estimation approaches for spaceborne applications, the SPN method does not require the formulation of hand-engineered features

Recognition of multifunction radar (MFR) is an open problem in the field of electronic intelligence. Parameters of MFR pulses are generally agile and difficult to distinguish statistically. A prospective way to realize credible MFR recognition is mining and exploiting more distinguishable high-dimensional patterns buried in pulse groups, which may be designed for implementing infrequently used radar

Compressive sensing (CS) has been widely used in multiple-input–multiple-output (MIMO) radar in recent years. Unlike traditional MIMO radar, detection/estimation of targets in a CS-based MIMO radar is accomplished via sparse recovery. In this article, for a CS-based colocated MIMO radar with linear arrays, we attempt to improve the target detection performance by reducing the coherence of the associated

We investigate the pursuit–evasion differential game (PE Game) for satellites with continuous thrust from the viewpoint of reachable domain (RD). A concept of hyper-reachable domain (HRD) is introduced to help analyze the problem, and a sufficient condition for capture in a PE Game is proposed based on the players’ HRD. Meanwhile, to practically use the RD as a tool to analyze the PE Game, an analytical

Most existing impact angle control guidance (IACG) laws that consider the reduced seeker field-of-view (FOV) focus only on a stationary or a nonmaneuvering moving target. In actual warfare, however, a number of targets are capable of maneuvering with lateral acceleration, which prohibits the existing FOV-constrained IACG laws from guaranteeing the reliable performance. In this article, we develop a

This article presents a new framework of real-time vision-based pose tracking for spacecraft in close range using geometric fitting of the imaged geometric primitives (GPs) on the spacecraft. At the first time instant, the tracking is initialized with the template-based pose retrieval and GP-based pose determination. At each subsequent time instant, with the pose prediction from the extended Kalman

CubeSat swarm in low earth orbit is an attractive alternative to present-day expensive and bulky satellite-based remote sensing systems. This article presents the design and optimization rules to achieve omnidirectional, high speed, long-range (more than 100 km) data communication among CubeSats. The unprecedented size, weight, power, and cost constraints imposed by the CubeSat platform and the availability

This article proposes a compressed-domain signal processing (CSP) multiple-input multiple-output (MIMO) radar, a MIMO radar approach that achieves substantial sample complexity reduction by exploiting the idea of CSP. CSP MIMO radar involves two levels of data compression followed by target detection at the compressed domain. First, compressive sensing is applied at the receive antennas, followed by

Geo-registration and geo-location of data collected by video sensors such as electro-optical and infrared cameras are two fundamental steps in the airborne surveillance of ground targets. With the availability of high-resolution imaging sensors and detailed mapping or terrain data sources, video data plays an increasingly important role in modern surveillance platforms like unmanned aerial vehicles

We consider the design of sets of discrete-phase, including binary/quaternary, sequences for phase-modulated continuous-wave multiple-input multiple-output radar in the presence of nonnegligible Doppler shift. We consider the peak sidelobes of auto- and cross-correlations in a desired interval of the Doppler shift as the performance metric of the design. Then, the design problem is formulated via imposing

With increased degrees of freedom of the transmitter, a coherent waveform-agile radar system can change its interpulse waveform to enhance the capability against increasingly sophisticated jamming and spoofing threats. Furthermore, radar agile waveform can provide better detection performance than a single waveform. In this article, we consider discrete phase coded sequence set design (DPCSSD) problem

Effective energy management systems are critical for long endurance stratospheric airships. This article presents a hybrid energy system consisting of one renewable (photovoltaic) and two energy storage (lithium battery/regenerative fuel cell) systems. After examining different models of energy harvesting, balancing, and storage, we present the details of a rule-based energy management strategy. We

A power converter for 60–400 Hz bilateral power conversion (BPC) is proposed in this article. This power converter is composed of three power switch arms, a set of filter inductors, a frequency decoupling circuit, a 60 Hz ac capacitor and a 400 Hz ac capacitor. The proposed BPC has the salient feature that it has the function of 60–400 Hz bilateral power conversion using only one power electronic converter

We consider 2-D localization and noncontact vital sign monitoring (i.e., determining the 2-D locations and estimating the rates of respiration and heartbeat) of multiple human objects via developing an impulse radio ultra-wideband (IR-UWB) distributed multi-input multi-output (MIMO) prototype radar system. A modified back projection algorithm is used to localize multiple objects. We also formulate

Traditionally, fuel-optimal problems for low-thrust spacecraft transfers are connected with energy-optimal problems to increase the convergence possibility of indirect methods. However, for low-thrust many-revolution missions, it is still hard to resolve the energy-optimal problems in a fast and reliable manner due to the strong nonlinearity. To address this issue, a warm-start multihomotopic optimization

We present an ultrashort range IEEE 802.11ad-based automotive joint radar-communications (JRC) framework, wherein we improve the radar's Doppler resilience by incorporating Prouhet–Thue–Morse sequences in the preamble. The proposed processing reveals detailed microfeatures of common automotive objects verified through extended scattering center models of animated pedestrian, bicycle, and car targets

In Part I [1] , a Korsch-based optical telescope design of a very high resolution earth observation satellite with a ground sampling distance of 25 cm is presented. In this part II, a system performance evaluation of the Korsch optical design employing a time-delay and integration charge-coupled device is investigated. Several key performance metrics are assessed, including the system modulation transfer

Electromagnetic vector sensor arrays can track both the polarization and direction of arrival (DOA) of the impinging signals. For linear crossed-dipole arrays, as shown by our analysis, due to inherent limitation of the structure, it can only track one DOA parameter and two polarization parameters. For full 4-D (two DOA, and two polarization parameters) estimation, we could extend the linear crossed-dipole

With the fast growing diffusion of real-time high-accuracy applications based on the global navigation satellite system (GNSS), the robustness of GNSS receiver performance has become a compelling requirement. Disruptive effects can be induced to signal processing stages of GNSS receivers due to the disturbances from radio frequency interference (RFI), even leading to a complete outage of the positioning

This article proposes a global navigation satellite system (GNSS) spoofing detection and classification technique for single-antenna receivers. We formulate an optimization problem at the baseband correlator domain by using the Least Absolute Shrinkage and Selection Operator (LASSO). We model correlator tap outputs of the received signal to form a dictionary of triangle-shaped functions and leverage

Missile autopilots for aerodynamic angle control and acceleration control are designed for fin-controlled missiles during the boost phase. In the boost phase, the speed change and the parameter variation of the missile are fast and large. To deal with the time-varying characteristics of the missile, the time-varying parameters are considered in nonlinear dynamics, and the parametric uncertainties are

A homing guidance law against a high-speed target in the exoatmospheric area is proposed based on the vector field approach. The vector field is designed and utilized to achieve head-on hit-to-kill interception. The trajectory of the target is predicted using the gravity acceleration model. The vector-field-based guidance law makes the missile converge to the predicted trajectory of the target, and

In this article, we propose a new compressive-sampling-based approach to detect a target and obtain its direction-of-arrival (DOA) by using samples collected by a set of sensor nodes. Since these sensors sample at a rate below Nyquist, instead of the Nyquist rate, the complexity, power consumption, memory requirement, and the volume of data that needs to be exchanged between sensors, are much lower

One of the main tasks involving the extended target tracking is how to partition the measurement set accurately and efficiently. In this article, an efficient graph-based partitioning algorithm is introduced for extended target tracking. To reduce the computational load and the interference of clutter on the measurement set partition, a measurement set preprocessing method based on density-based clustering

This article discusses the maintenance of an $L_1$ -type artificial equilibrium point in the Sun–[Earth+Moon] circular restricted three-body problem by means of an electric solar wind sail. The reference configuration instability is compensated for with a feedback control law that adjusts the grid voltage as a function of the distance from the natural $L_1$ point. Two different control strategies are

Tracking space noncooperative targets, including disabled and mobile spacecrafts, remains a challenging problem. This article develops two reinforcement-learning-based parameter-self-tuning controllers for the following two different tracking cases: case A, tracking a disabled target, and case B, tracking a mobile target. An adaptive controller consisting of five model uncertainties is adopted for

Presents the table of contents for this issue of the publication.