利用短波

The main job and contribution of this paper are as follows:Based on narrowband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, compute the cross-correlation function of FH signals from multichannels, then we get the cross power spectral density matrixCSDM Secondly, select the hops of FH signals from the CSDM via processing and analyzing the CSDM, meanwhile reduce the influence coming from noise, fixed frequency signal and other interferences; Lastly, estimating the DOA of every hop and according to the DOA, we can separate the hops, get the number of FH signals and their parameters. Propose a new method for designing the threshold in FH signal detection. This method makes it easy to get the threshold by theoretic computing and it can extremely reduce the interference of non-FH signals.Based on broadband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, get the DOA of the signals by wideband spatial spectrum estimation; secondly, separate the signals by spatial filtering using wideband beamformer; Lastly, we propose two methods for FH signal blind detection and blind parameter estimation, one is for several constant hop-rate FH signals whose dwell-time are different and another is for a single FH signal whose hop-rate is alterable.By employing spatial interpolation in broadband signal beamforming, it can reduce the number of antenna elements and corresponding RF modules, A/D converters, etc. It can also eliminate the mutual coupling between antenna elements while getting the narrower main beamwidth and lower sidelobe level.

本文的主要研究工作和贡献如下：●提出了一种基于窄带处理的FH信号盲检测和参数盲估计的实现方法，即首先求出多路信号之间的互相关，进而得到互功率谱密度矩阵，然后通过对CSDM进行对折处理来抑制噪声、定频信号及其他干扰的影响，并将所有属于FH信号的hop(每一跳的驻留时间在时频图上持续的线段)从CSDM中筛选出来，最后用阵列信号处理中的到达方向估计理论在频域中估计出各个hop的方向参数，利用方位信息完成FH信号分离并得到FH信号的数目及其各自的参数集；●提出了一种确定FH信号检测门限的策略，该策略不仅使得检测门限能够通过理论计算得到，而且还显著地抑制了非跳频信号的干扰，从而能有效地检测出FH信号；●提出了一种基于宽带处理的短波FH信号盲检测和参数盲估计的实现方法，即首先利用宽带空间谱测向技术得到接收信号的DOA，然后采用宽带波束形成技术对特定方向进行空间滤波，实现多个信号的分离，最后分别提出了两种FH信号的盲检测和参数盲估计方法，第一种方法适用于空间某个特定方向上存在着几个驻留时间不同的恒跳速FH信号和其他干扰信号的混合信号，第二种方法适用于空间某个特定方向上仅含一个可变跳速的FH信号和噪声的混合信号；●将空间插值的概念和宽带波束形成技术结合起来，提出了一种基于频域处理的宽带恒定束宽的波束形成方法。

The "NVIS"(Near-Vertical Incidence Sky wave) antenna is set on the horizon, which can clear up the dead zone of short-wave communication, and a ferrite loading spiral coil antenna is installed on the rocker projectile to receive the short wave signal.

在地面设置近垂直入射天波传播"NVIS"天线，消除短波通信静区，弹上安装铁氧体加载螺旋线圈天线接收短波信号，利用原有弹载计算机进行数据处理。

This study attempted to extract lithlogical and mineralogical information in the arid region using the ASTER multispectral data.

本研究尝试利用ASTER 可见光近红外和短波红外的多光谱遥感数据提取干旱地区的岩石与矿物信息。

Combining a new geoid model (EIGEN-GL04S) recovered from GRACE mission and the KMSS04 model, a new mean dynamic ocean topography model are estimated over the Antarctic region. The surface Antarctic Circumpolar Current field and its Polar Front and sub-Antarctic Front are derived from MDT after filtering with a wavelet denoising method.

联合基于GRACE重力卫星观测资料恢复的重力场模型(EIGEN-GL04S1)和卫星测高推求的平均海面高模型(KMSS04)来构造南极绕极流区域的平均海面动力地形，并利用小波滤波方法去掉短波及噪声信号，进而推算大、中尺度的绕极流。

The first radio broadcasts were made in Britain in 1927 on short wave.

最早的无线电广播是在1927年在英国利用短波实现的。

This paper presents a prediction model of frequency parameters of short-wave communication based on non-singleton fuzzy system.

提出一种利用非单点模糊系统建模的短波通信频率参数预测模型。

Based on the heat balance equation of the vegetation canopy layer and the assumption that its short wavelength absorptance, long wavelength emissivity, heat or moisture transfer coefficient, and bulk stomatal resistance are random, uncorrelated variables with normal distribution densities, the theoretical modeling for IR radiance statistics of vegetation canopy surface is presented by Monte Carlo simulation, with the surface radiative temperature statistical distribution given.

根据植被层能量热平衡方程，选取植被短波吸收率、长波发射率、热与水汽传输系数和气孔阻力为独立的随机变量，并假设它们均服从正态分布，利用Monte－Carlo方法，模拟计算了植被表面红外辐射的统计特性。

Summer monsoon precipitation in 1998 is simulated with different soil temperature and solar short wave radiation parameterization schemes using the improved p-σ nine level hybrid coordinate model.It is found that the improved soil temperature calculation method together with Lacis and Hansen short wave radiation parameterization has a good simulation for precipitation.

利用改进后的p-σ 9层混合坐标系模式，采用不同的土壤温度与太阳短波辐射参数化方案，对1998年夏季风降水进行模拟，发现改进的土壤温度计算法和改进的Lacis和Hansen 短波辐射参数化方法相结合能较好地模拟降水。

The absorption spectrum center wavelength of dolomite is near 232 μm is shorter than 235 μm of limestone,and thus RBD7 and RBD8 can be employed effectively to identify dolomite and limestone,respectively. Felsic rocks show AlOH and Fe3+ absorption characteristics in the VNIRSWIR region,while the maficultramafic rocks show Fe2+ and Fe,MgOH absorption features,hence the use of different valence state of iron and secondary minerals can distinguish them:ASTER band2/band1 represent Fe3+ distribution,ASTER band2/band1 represent the Fe2+ distribution,RBD6 can estimate the AlOH mineral abundance. Psammitic/pelitic schist containing phengite,chlorite,stilpnomelane,as well as the weathered surface covered by clay minerals,exist characteristic absorption spectrum in the 221 μm(band 6),and has a high reflectance in 165 μm(band 4),while the blueschist/greenschist show high reflectance in the 221 μm(band 6),and it exit low reflectance in 165 μm(band 4),and blueschist/greenschist appear low ASTER band4/band6 ratio.

白云岩的CO2-3吸收谱带中心波长位于232〖KG*3〗μm，与灰岩的CO2-3 吸收谱带中心波长位置235 μm相比，具有向短波长方向移动的特点，据此可以利用RBD7、RBD8分别有效的识别白云岩和灰岩；长英质岩石显示AlOH和Fe3+ VNIRSWIR吸收特征，而基性超基性岩石显示Fe2+和Fe、MgOH特征，利用不同的铁价态和次要矿物可以区分它们：ASTER band2/band1代表了含Fe3+矿物分布信息、ASTER band5/band4代表了含Fe2+矿物分布信息、RBD6可以估计AlOH矿物的丰度；砂质/泥质片岩含较多的多硅白云母、绿泥石、黑硬绿泥石以及风化后表面覆盖的其它粘土矿物，在221 μm（band 6）存在有特征的吸收谱带，并且在165 μm（band 4）具有较高的反射率，而蓝片/绿片岩在221 μm（band 6）反射率较高，不具有明显特征吸收谱带，同时其在165 μm（band 4）反射率较低，因此蓝片/绿片岩ASTER band4/band6 比值低。

EPL makes use of short wave band glare to kill propanoic acid bacillus of acne inner , makes use of red light , infrared brightness to lower as well as radio-frequency current removes a color while the combination effect reducing sebaceous gland activity and , stimulates the deep collagen hyperplasia , restores a scar.

EPL利用短波段的强光杀死痤疮内的丙酸杆菌，并利用红光、红外光以及射频电流组合作用在降低皮脂腺活性的同时消除色沉，刺激深层胶原增生，修复疤痕。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。