Studying the positioning accuracy for dynamic (moving) objects with the use of multifrequency oblique-incidence sounding of ionospheric radio channels by chirp signals

The paper presents the methods and algorithms for positioning the dynamic (moving) objects using the oblique-incidence ionospheric sounding by chirp signals. Full-scale experiments have been performed to determine a distance to an object and its location.     

The Juno Radiation Monitoring (RM) Investigation

The Radiation Monitoring Investigation of the Juno Mission will actively retrieve and analyze the noise signatures from penetrating radiation in the images of Juno’s star cameras and science instruments at Jupiter. The investigation’s objective is to profile Jupiter’s \(>10\mbox{-MeV}\) electron environment in regions of the Jovian magnetosphere which today are still largely unexplored. This paper discusses the primary instruments on Juno which contribute to the investigation’s data suite, the measurements of camera noise from penetrating particles, spectral sensitivities and measurement ranges of the instruments, calibrations performed prior to Juno’s first science orbit, and how the measurements may be used to infer the external relativistic electron environment.     

The Noise Model of the SEIS Seismometer of the InSight Mission to Mars

The SEIS (Seismic Experiment for Interior Structures) instrument on board the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. The InSight noise model is a key tool for the InSight mission and SEIS instrument requirement setup. It will also be used for future operation planning. This paper presents the analyses made to build a model of the Martian seismic noise as measured by the SEIS seismometer, around the seismic bandwidth of the instrument (from 0.01 Hz to 1 Hz). It includes the instrument self-noise, but also the environment parameters that impact the measurements. We present the general approach for the model determination, the environment assumptions, and we analyze the major and minor contributors to the noise model.     

分布式数字相控阵通道一致性校准方法

基于分布式数字相控阵通道一致性校准需求,提出了一种新的有效解决方法。首先基于时域相干的时延估计算法纠正通道间时延差,而后利用基于最小二乘拟合的频域均衡算法实现通道间幅相一致性校准。利用MATLAB平台进行仿真分析,结果表明,利用此方法校正后,失配通道与参考通道在通带内的幅度差值在0.015d B内,相位差值在0.1°内,有效地实现了通道间一致性校准作用。该方法已成功应用于实际工程项目中。     

光纤陀螺标度因数及零偏温度误差补偿研究

首先分析了光纤陀螺产生温度误差的机理,在此基础上分别指出标度因数与零偏的误差补偿模型,提出了一种利用一组数据同时补偿标度因数及零偏的方法,直接表示输入与标度因数零偏补偿后的关系。最后通过实验验证了该方法不仅能够有效地补偿陀螺的温度误差,且其补偿精度优于原单独补偿的方法,同时该方法仅需一次温度实验,节省实验成本,具有较大的现实意义。     

CCD互相关粒子图像测速及其在对抗流流场测量中的应用

在常规自相关粒子图像测速（ＰＩＶ）系统的基础上,发展了一个采用ＣＣＤ像机的互相关粒子图像测速系统。用这一新系统测量了对抗流流场的结果表明,这一技术克服了自相关粒子图像测速技术在测量具有滞止点的流场中的困难。实验说明,与自相关粒子图像测速技术相比,这一技术更快捷有效。     

Validation and comparison of coordinated turn aircraft maneuvermodels

A major challenge posed by aircraft tracking problems is the nondeterministic nature of an aircraft flight, due to the difficulty of predicting the pilot's actions. Accurate aircraft maneuver models are however highly desirable, particularly in air defense applications, to achieve accurate tracking and prediction. Through analysis of actual fighter aircraft trajectories and comparison with the Singer maneuver model, particularly in terms of prediction performance, coordinated turn (CT) aircraft maneuver models are presented, compared, and validated. A more general CT model is shown to better model actual trajectories than the classical CT model used in the literature     

Mortality and morphological anomalies related to the passage of cosmic heavy ions through the smallest flowering aquatic plant Wolffia arrhiza

Radiobiological effects of single cosmic heavy ions on individual, actively metabolizing test organisms, plants of Wolffia arrhiza, have been explored in an experiment flown aboard the Russian Biosatellite 10. Mortality induced during space flight, population dynamics during subsequent cultivation, and morphological anomalies occurring in the plants of these cultures were investigated. Correlation of these effects with the passage of a heavy ion was achieved by inserting monolayers of plants in a stack of surrounding plastic nuclear track detectors (BIO-STACK). Enhanced initial mortality and delayed decline of induced anomalies have been significantly associated with the passage of single heavy ions, in particular if ions penetrated the budding region of the plants. The prolonged persistence of anomalies in filial generations as an indication of delayed genetic damage has been detected for the first time as the consequence of the hit by a single heavy ion. Regarding radiation protection of space crew during prolonged missions, especially outside the magnetosphere, this appears to be a significant finding.     

Experimental investigations of quasistable radiation belts formed after solar proton events in September–October 1989 and March 1991 based on measurements made by “Liulin” dosimeter-radiometer on board the “MIR” space station

Since 1988 high sensitivity dosimeter-radiometer “Liulin” has been installed on board the MIR space station. Device measured absorbed dose rate and flux of penetrating particles. Results of measurements showed that after powerful solar proton events (SPE) September–October, 1989 and March, 1991 additional quasistable radiation belts were formed in the near earth space within the interval L=1.8−3.0. These “new” belts were observed as an additional maximums in flux (and sometimes dose) channels when crossing the SAA region. “New” belts were quasi stable and existed at least several months, decaying slightly after SPE. Dose to flux ratio analysis showed that major components of these belts were energetic electrons and protons arising in connection with preceding SPEs.     

Microwave spectrum analysis as solar energy release diagnostics

The possibilities of using spectrographic observations of microwave radio emission as a solar flare plasma diagnostic are discussed. The spectral fine structure of the emission is interpreted in the context of plasma emission mechanisms. The balance equations for particles and plasma turbulence together with the transfer equations for electromagnetic waves in a plasma are solved for a model containing a diverging magnetic loop. As a result of the analysis of the blip-type spectral feature, the structure of energy release region and the unperturbed plasma concentration in the preflare loop are evaluated. The number of accelerated electrons and the intensity of the plasma turbulence in the source region are estimated using the properties of the weak continuum emission following the blip. Based on the degree of circular polarization of both the narrow band and the continuum emission, estimates for the external magnetic field strength and the angular width of the radiating plasma turbulence have been obtained.