Rosette Scanning Research Articles

Three-dimensional drift correction of localised non-raster scanning on atomic force microscopy

Abstract Non-raster scanning can increase the scanning frame rate and measurement speed of atomic force microscopes (AFMs). It is also possible to correct the 3D drift during the non-raster scanning. However, the algorithm for the drift correction depends upon the properties of each scan pattern. While localised non-raster scanning using a rosette scan may be faster than the frequently used Lissajous scanning patterns, the drift correction is more challenging because the scan has crossing points only in local neighbouring segments where there are short temporal and spatial separations of the crossing paths. This design note presents a novel solution that successfully overcomes this problem and extends a drift correction method previously developed for Lissajous scans to the 3D drift correction of localised non-raster scanning using a rosette scan trajectory. The drift in the X, Y and Z axes can be determined using the crossing points and locally repeated scans of the same features. The general procedure is presented together with experiments using rosette scans of a two-dimensional lateral calibration standard. Experimental results have demonstrated that the method can effectively correct both the drift in the three axes and sample tilt, leading to significantly improved images. The method requires only localised crossing points in the scan and does not need additional scans to determine the three-dimensional drift based on cross-correlation and least squares techniques, and it can be used with any AFMs capable of rosette scanning.

Modeling fast jet infrared countermeasures: Pseudo-imaging seekers with an ultraviolet guard band

In 2012, a study looking back 35 years indicated that 90% of all aircraft losses in battle were caused by infrared (IR) guided missiles. Man portable air defense systems are a cheap and prolific resource for both state and non-state actors that enables the employment of IR guided missiles. As such, significant time is required to be invested in developing effective countermeasures to ensure a fast jet can attain and sustain air superiority in operations. This article will provide a summary of the thesis by Glover (Glover AX. Electro-optic countermeasure modelling in a fast jet environment: rosette scanning seekers with an ultraviolet guard band. Thesis, Cranfield University, 2019) that aimed to develop a myriad of IR-based countermeasure techniques. Specifically, when pseudo imaging, a rosette scan IR seeker is employed against a fast jet with an ultraviolet guard band counter-countermeasure. A series of seven trials was simulated using Chemring’s CounterSim program to produce a spread of results based on the developed technique’s effectiveness. Several of these trials produced outcomes with a probability of escaping hit greater than 97% across a range of altitudes. The successful techniques involve an assortment of concepts, including employment of spectral flares, aircraft maneuvering, multi-flare patterns, and the notion of masking.

防护罩气动热效应对玫瑰扫描系统的影响仿真分析

防护罩气动热效应对玫瑰扫描系统的影响仿真分析

防护罩气动热效应对玫瑰扫描系统的影响仿真分析

防护罩气动热效应对玫瑰扫描系统的影响仿真分析

Image Recovery of an Infrared Sub-Imaging System Based on Compressed Sensing

An infrared (IR) sub-imaging system is composed of an optical scanning device and a single IR detector, which provides the target location information to the servo system. Currently, further improvement of positioning accuracy and imaging quality in the traditional rosette scanning guidance mode is experiencing a bottleneck. The emergence of the compressed sensing (CS) technique provides a new solution for this problem as it can recover a high-resolution IR image including richer information with fewer sampling points. In this paper, the complementarity of the CS framework and IR rosette sub-imaging system was analyzed. A new method to improve the resolution of reconstructed IR images, multi-frame joint compressive imaging (MJCI), was proposed. The simulation results revealed the potential of the CS technique when applied to the IR sub-imaging system and demonstrated that the proposed method performed well for reconstruction.

Image reconstruction of dynamic infrared single-pixel imaging system

Single-pixel imaging technique has recently received much attention. Most of the current single-pixel imaging is aimed at relatively static targets or the imaging system is fixed, which is limited by the number of measurements received through the single detector. In this paper, we proposed a novel dynamic compressive imaging method to solve the imaging problem, where exists imaging system motion behavior, for the infrared (IR) rosette scanning system. The relationship between adjacent target images and scene is analyzed under different system movement scenarios. These relationships are used to build dynamic compressive imaging models. Simulation results demonstrate that the proposed method can improve the reconstruction quality of IR image and enhance the contrast between the target and the background in the presence of system movement.

复杂背景下玫瑰扫描红外探测系统作用距离评估方法

复杂背景下玫瑰扫描红外探测系统作用距离评估方法

Image reconstruction for single detector rosette scanning systems based on compressive sensing theory

Compressive sensing (CS) is a signal processing technique that enables a signal that has a sparse representation in a known basis to be reconstructed using measurements obtained below the Nyquist rate. Single detector image reconstruction applications using CS have been shown to give promising results. In this study, we investigate the application of CS theory to single detector infrared (IR) rosette scanning systems which suffer from low performance compared to costly focal plane array (FPA) detectors. The single detector pseudoimaging rosette scanning system scans the scene with a specific pattern and performs processing to estimate the target location without forming an image. In this context, this generation of scanning systems may be improved by utilizing the samples obtained by the rosette scanning pattern in conjunction with the CS framework. For this purpose, we consider surface-to-air engagement scenarios using IR images containing aerial targets and flares. The IR images have been reconstructed from samples obtained with the rosette scanning pattern and other baseline sampling strategies. It has been shown that the proposed scheme exhibits good reconstruction performance and a large size FPA imaging performance can be achieved using a single IR detector with a rosette scanning pattern.

Effective expendable countermeasure model against dual-band infrared and ultraviolet man-portable air-defence seeker systems

The ultraviolet (UV) band of the electromagnetic spectrum has the potential to be used as the host medium for the operation of guided weapons. Unlike in the infrared (IR) band, a target propelled by an air-breathing jet engine produces no detectable radiation in the UV band and is opaque to the background UV produced by the sun. Successful engineering of spectral airborne IR countermeasures (CMs) against existing two-color IR seekers has encouraged missile counter-countermeasure designers to utilize the silhouette signature of an aircraft in the UV as a means of distinguishing between a true target and a flare CM. We describe the modeling process of a dual-band IR and UV rosette scan seeker using CounterSim, a missile engagement, and countermeasure simulation software package developed by Chemring Countermeasures Ltd. Results are shown from various simulated engagements of the dual-band man-portable air defence (MANPAD) system with a C-130 Hercules. These results have been used to estimate the aircraft’s baseline vulnerability to this MANPAD threat and to develop a model flare countermeasure that is successful in greatly improving the survivability of the aircraft.

Frame frequency prediction for Risley-prism-based imaging laser radar.

A dual-wedge scanner has potential applications in laser imaging radar. To realize fast scanning imaging without a blind region, the rotation rates of the wedges have to be controlled to perform beam scanning along appropriate track paths. The first-order paraxial approximation method is employed to investigate the 2D scan patterns and path density for different angular frequency ratios of the wedges rotating steadily in the same and opposite directions. The frame rate of no-blind-region scanning imaging is estimated in terms of the imaging coverage requirement. The internal relations between the rotation rates, the instantaneous field of view (IFOV), and the imaging velocity are revealed. The results show that the spiral scanning trace, resulting from co-rotating wedges, is dense in the center and sparse at the edge of the scanning field. The reverse results can be obtained for the rosette scanning trace, resulting from counter-rotating wedges. The denser the scanning trace is, the longer the scan period is. The faster the wedges rotate and the wider the IFOV is, the higher the frame rate is. When the ratio of the width of IFOV to the angular radius of the scanning field is 0.15, the frame rate of no-blind-region spiral scanning imaging can be up to 18 fps for wedge rotation rate of 12000 r/min, and that for rosette scanning imaging can be up to 20 fps.

Modelling an advanced ManPAD with dual band detectors and a rosette scanning seeker head

Man Portable Air Defence Systems (ManPADs) have been a favoured anti aircraft weapon since their appearance on the military proliferation scene in the mid 1960s. Since this introduction there has been a ‘cat and mouse’ game of Missile Countermeasures (CMs) and the aircraft protection counter counter measures (CCMs) as missile designers attempt to defeat the aircraft platform protection equipment. Magnesium Teflon Viton (MTV) flares protected the target aircraft until the missile engineers discovered the art of flare rejection using techniques including track memory and track angle bias. These early CCMs relied upon CCM triggering techniques such as the rise rate method which would just sense a sudden increase in target energy and assume that a flare CM had been released by the target aircraft. This was not as reliable as was first thought as aspect changes (bringing another engine into the field of view) or glint from the sun could inadvertently trigger a CCM when not needed. The introduction of dual band detectors in the 1980s saw a major advance in CCM capability allowing comparisons between two distinct IR bands to be made thus allowing the recognition of an MTV flare to occur with minimal false alarms. The development of the rosette scan seeker in the 1980s complemented this advancement allowing the scene in the missile field of view (FOV) to be scanned by a much smaller (1/25) instantaneous FOV (IFOV) with the spectral comparisons being made at each scan point. This took the ManPAD from a basic IR energy detector to a pseudo imaging system capable of analysing individual elements of its overall FOV allowing more complex and robust CCM to be developed. This paper continues the work published in [1,2] and describes the method used to model an advanced ManPAD with a rosette scanning seeker head and robust CCMs similar to the Raytheon Stinger RMP.

Increasing Accuracy of Tracking Loop for the Rosette Scanning Seeker Using Improved ISODATA and Intelligent Center of Gravity

Increasing Accuracy of Tracking Loop for the Rosette Scanning Seeker Using Improved ISODATA and Intelligent Center of Gravity

Antenna scanning techniques for estimation of spacecraft position

Scanning movements are added to a tracking antenna's trajectory to estimate the true spacecraft position. The scanning movements are composed of the harmonic axial movements of an antenna. This motion produces power variations of the received signal, which are used to estimate the spacecraft's position. Three different scanning patterns (conical scan, Lissajous scan, and rosette scan) are presented and analyzed in this paper. The analysis includes the evaluation of the estimation errors due to random or harmonic variation of the antenna's position, and due to random and harmonic variations of the power level. Typically, the estimation of the spacecraft's position is carried out after completing a full scanning cycle. Sliding-window scanning is introduced in this paper, wherein the spacecraft-position estimation is carried out in an almost-continuous manner, and it reduces the estimation time by half.

New infrared counter-countermeasure technique using an iterative self-organizing data analysis algorithm for the rosette scanning infrared seeker

Hyun-Ki HongChung-Ang UniversityGraduate School of Advanced ImagingScience, Multimedia, and FilmDepartment of Image EngineeringImage and Information Laboratory221 Heuksuk-Dong, DongJak-KuSeoul 156-756, South KoreaE-mail: jsk@candy.ee.cau.ac.krDong-Sun SeoMyong-Ji UniversityDepartment of Electronic EngineeringYonginKyonggido 449-728, South KoreaJong-Soo Choi,

Dynamic simulation of the rosette scanning infrared seeker and an infrared counter-countermeasure using the moment technique

Dynamic simulation of the rosette scanning infrared seeker and an infrared counter-countermeasure using the moment technique

Design of two-degree-of-freedom robust controllers for a seeker scan loop system

A mathematical model of a seeker scan loop plant is derived. The scanning accuracy of the seeker scan loop is degraded by modelling uncertainty and disturbance. To satisfy robust stability as well as robust performance, a new two-degree-of-freedom (TDF) robust control is formulated in the framework of H optimization problem. The TDF controller consists of the feedback controller for robust stabilization and the feedforward controller for good command following. Two structures, such as the conventional and modified structures, of TDF control are introduced, and the formulations of the TDF H control are presented for both structures. The feedback and feedforward controllers are designed in a single-step procedure. The proposed formulation is able to reflect not only frequency-domain specifications but also time-domain specifications such as transient response characteristics and multivariable interaction between output channels, differently from the mixed-sensitivity problem. The seeker scan loop system with the TDF control satisfies design requirements and in particular shows good scanning performances for conical and rosette scan patterns.

Design and analysis of improved instantaneous field of view of rosette scanning infrared seeker

The authors propose two methods: one is to design an improved instantaneous field of view (IFOV) of rosette scanning infrared seeker (RSIS): the other is to analyse full scan coverage (FSC) over a total field of view (TFOV). The proposed methods give a smaller IFOV than that of previous methods, and a low noise equivalent flux density (NEFD).