深圳雷地参与“神舟”五号飞天

深圳雷地科技实业公司收到中国人民解放军总装备部航天医学工程研究所的感谢信，感谢雷地公司“协作配套研制的产品参加了我国首次载人航天飞行任务。在神舟五号飞船测试、发射、运行和回收的各个阶段，产品性能稳定，工作正常，有力地配合了我所圆满完成本次意义重大的参试任务。”原来，航天员杨利伟头盔面罩上的“保护膜”及宇航服上金属部件的表面处理，就是雷地公司研制完成的。

雷地 能够自我复制是企业成熟的标志

“雷地已经度过了创业期。能够自立、自我复制是企业走出创业期，进入成熟发展阶段的标志。”深圳新洲南路雷地集团总部的大厅、会议室里，又增加了很多深圳雷地公司董事长刘南林和大人物们的合影，刘南林还是一笑两个大酒窝．不过比三年前胖了一点．酒窝没有那么深了。

雷地科技 跟头中“摔”出常识

摔了跟头的雷地仔细地想自己能做什么。

金刚石膜铺就雷地科技

“神舟五号”载人飞船2003年遨游太空，是令中国人骄傲的一件事。而深圳“雷地人”更感自豪的是，他们亲身参与了这一盛事。在中国宇航员所配戴的头盔面罩上，镀有一层特殊的“保护膜”，这种膜可以加强面罩的硬度，增强导热性，阻隔电磁辐射，还可防止氧气泄露，这就是深圳雷地科技拥有完整知识产权的金刚石膜技术。

Application of 3D GPR attribute technology in archaeological investigations

Ground penetrating radar （GPR） attribute technology has been applied to many aspects in recent years but there are very few examples in the field of archaeology. Especially how can we extract effective attributes from the two- or three-dimensional radar data so that we can map and describe numerous archaeological targets in a large cultural site？ In this paper, we applied GPR attribute technology to investigate the ancient Nanzhao castle-site in Tengchong, Yunnan Province. In order to get better archaeological target （the ancient wall, the ancient kiln site, and the ancient tomb） analysis and description, we collated the GPR data by collected standardization and then put them to the seismic data processing and interpretation workstation. The data was processed, including a variety of GPR attribute extraction, analysis, and optimization and combined with the archaeological drilling data. We choose the RMS Amplitude, Average Peak Amplitude, Instantaneous Phase, and Maximum Peak Time to interpret three archaeological targets. By comparative analysis, we have clarified that we should use different attributes to interpret different archaeological targets and the results of attribute analysis after horizon tracking is much better than the results based on a time slice.

Recursive impedance inversion of ground-penetrating radar data in stochastic media

The travel time and amplitude of ground-penetrating radar （GPR） waves are closely related to medium parameters such as water content, porosity, and dielectric permittivity. However, conventional estimation methods, which are mostly based on wave velocity, are not suitable for real complex media because of limited resolution. Impedance inversion uses the reflection coefficient of radar waves to directly calculate GPR impedance and other parameters of subsurface media. We construct a 3D multiscale stochastic medium model and use the mixed Gaussian and exponential autocorrelation function to describe the distribution of parameters in real subsurface media. We introduce an elliptical Gaussian function to describe local random anomalies. The tapering function is also introduced to reduce calculation errors caused by the numerical simulation of discrete grids. We derive the impedance inversion workflow and test the calculation precision in complex media. Finally, we use impedance inversion to process GPR field data in a polluted site in Mongolia. The inversion results were constrained using borehole data and validated by resistivity data.

High resolution GPR and its experimental study

We develop a high resolution ground penetrating radar system （LANRCS-GPR） based on the E5071B Vector Network Analyzer （VNA）. This system takes advantage of a wideband and adjustable frequency domain ground penetrating radar system and adds the characteristics of a network analyzer with ultra-wideband and high precision measurement. It adopts the LAN mode to concatenate system control that reduces construction cost and makes the system easy to expand. The high resolution ground penetrating radar system carries out real time imaging using F-K migration with high calculation efficiency. The experiment results of the system indicate that the LANRCS-GPR system provides high resolution and precision, high signal-to-noise ratio, and great dynamic range. Furthermore, the LANRCS-GPR system is flexible and reliable to operate with easy to expand system functions. The research and development of the LANRCS-GPR provide the theoretical and experimental foundation for future frequency domain ground penetrating radar production and also can serve as an experimental platform with high data gathering precision, enormous information capability, wide application, and convenient operation for electromagnetic wave research and electromagnetic exploration.

Distribution of ice thickness and subglacial topography of the "Chinese Wall" around Kunlun Station,East Antarctica

As fundamental parameters of the Antarctic Ice Sheet,ice thickness and subglacial topography are critical factors for studying the basal conditions and mass balance in Antarctica.During CHINARE 24（the 24 th Chinese National Antarctic Research Expedition,2007/08）,the research team used a deep ice-penetrating radar system to measure the ice thickness and subglacial topography of the ＂Chinese Wall＂ around Kunlun Station,East Antarctica.Preliminary results show that the ice thickness varies mostly from 1600 m to 2800 m along the ＂Chinese Wall＂,with the thickest ice being 3444 m,and the thinnest ice 1255 m.The average bedrock elevation is 1722 m,while the minimum is just 604 m.Compared with the northern side of the ice divide,the ice thickness is a little greater and the subglacial topography lower on the southern side,which is also characterized by four deep valleys.We found no basal freeze-on ice in the Gamburtsev Subglacial Mountains area,subglacial lakes,or water bodies along the ＂Chinese Wall＂.Ice thickness and subglacial topography data extracted from the Bedmap 2 database along the ＂Chinese Wall＂ are consistent with our results,but their resolution and accuracy are very limited in areas where the bedrock fluctuates intensely.The distribution of ice thickness and subglacial topography detected by ice-penetrating radar clarifies the features of the ice sheet in this ＂inaccessible＂ region.These results will help to advance the study of ice sheet dynamics and the determination of future locations of the GSM＇s geological and deep ice core drilling sites in the Dome A region.

Signal and Data Processing of Television Based on Multistatic Radar Systems

A television based multistatic radar system is described. The commercial television transmitter is used as the illuminator in the multistatic radar system. The reflected commercial television signals are measured by an array of sensors. A data processing scheme is developed that adapts to the poor signal processing ability. The innovation is focused on the construction of the observation space, which could reduce the non linearity error. The new method leads to better system stability than the traditional one. Monte Carlo simulation is utilized and compared with the traditional method.

Research on High-Accuracy Programmable Timer Used in Acquiring UWB Signals

UWB signal digitization depends, to a large extent, on the accuracy of sampling time. A highaccuracy programmable timer is therefore the key to implementing UWB signal data acquisition. A high-accuracy programmable timer based on the principle of ramp generators is described in this paper. The counting range of the timer is up to 16 bits, the timing precision is 8 ps, and the equivalent sampling rate is up to 50G Hz. No other identical product has been reported so far. This timer was successfully used in the data acquisition system for geological radar signals developed by us.

An approach to estimate tidal dissipation with single-point high-frequency ground wave radar data

Using the single-point ground wave （GW） radar data at Shensi Station and the water level data at three stations （Shengsi, Luchaogang and Daishan）, the authors obtained the flow vectors from the radial velocity of GW radar observation, and calculate four sub-tidal harmonic constants （O1, K1, M2 and S2）. The tidal characteristics derived from the GW radar dataset agreed well with those from the tidal gauge data. The authors also analyzed the tidal energy flux and tidal energy dissipation rate. There was a good relationship between the tidal energy dissipation rate and topography. The study showed a good way to calculate tidal energy dissipation rate using GW radar data.

五十岁的父亲,你真的要“走”吗?

父亲,您是个极为普通的农民,也是世界上独一无二、无微不至的父亲。自从母亲去世后,您便成了爹娘两兼的人,独自挑起了黑土地上的庄稼,挑起了五谷丰登的喜悦;

《雪地里的小画家》重难点的教学

《雪地里的小画家》(义务教育小学语文第一册19课)是篇韵文,讲的是雪地里一群小画家画画的事,旨在让学生知道小鸡、小狗、小鸭、小马四种动物脚趾的不同及青蛙冬眠的特征。插图画的是小画家(小鸡、小狗、小鸭、小马)正在雪地上画画(身后留下一串脚印)。

世界首台1平方米光学级金刚石膜生产设备问世

实现工业化生产的金刚石膜生产设备由雷地科技集团自行研发制造、并拥有自主知识产权，在生产设备制造方面，最近取得三项世界首创：常温下生产金刚石膜材料；金刚石膜面积达1平方米的生产设备；光学级金刚石膜产品。目前，雷地科技集团拥有的1平方米金刚石膜生产设备是迄今国际上生产金刚石膜材料的最大型设备。

Modified Method for Estimating Organic Carbon Density in Discontinuous Karst Soil Using Ground-Penetrating Radar and Geostatistics

The conventional method which assumes the soil distribution is continuous was unsuitable for estimating soil organic carbon density(SOCD) in Karst areas because of its discontinuous soil distribution. The accurate estimation of SOCD in Karst areas is essential for carbon sequestration assessment in China. In this study, a modified method,which considers the vertical proportion of soil area in the profile when calculating the SOCD, was developed to estimate the SOCD in a typical Karst peak-cluster depression area in southwest China. In the modified method, ground-penetrating radar(GPR) technology was used to detect the distribution and thickness of soil. The accuracy of the method was confirmed through comparison with the data obtained using a validation method, in which the soil thickness was measured by excavation. In comparison with the conventional method and average-soil-depth method,the SOCD estimated using the GPR method showed the minimum relative error with respect to that obtained using the validation method. At a regional scale, the average SOCDs at depths of 0-20 cm and 0-100 cm, which were interpolated by ordinary kriging,were 1.49(ranging from 0.03-5.65) and 2.26(0.09-11.60) kgm-2based on GPR method in our study area(covering 393.6 hm2), respectively. Therefore, the modified method can be applied on the accurate estimation of SOCD in discontinuous soil areas such as Karst regions.

Evaluating some factors that affect feasility of using ground penetrating radar for landmine detection

Ground penetrating radar （GPR） is one of the promising technologies that can be used to detect landmines. Many factors may affect the ability of GPR to detect landmines. Among those factors are： 1） the type of landmine material （metallic or plastic）, 2） conditions of the host soil （soil texture and soil moisture）, and 3） the radar frequency utilized. The impact of these factors on the ability of GPR to detect landmines is investigated by studying their effect on the dielectric permittivity contrast between the landmine and the host soil, as well as on the attenuation of the radar waves. The impact of each factor was theoretically reviewed and modeled using the Matlab and Mathcad software packages. Results of the computer modeling were correlated with GPR data acquired for metallic and plastic landmine types. It was found that the ability of GPR to detect landmines depends to a great extent on the landmine type, water content of the host soil, utilized radar frequency, and soil texture. The landmines are much easier to detect than plastic landmines for any soil conditions and any radar frequency. Increasing the soil＇s moisture content, regardless of soil texture, eases the detection of the plastic landmine and worsens the detection of the metallic mines. Increasing the percentage of clay in the soil causes the same effect as the moisture content. However, higher radar frequency delivers better results for landmine detection as long as the percentage of clay and the moisture content in the soil remains low. The results of this study are expected to help in selecting optimum radar antennae and data acquisition parameters depending on the landmine type and environmental conditions.

A NOVEL SVM FOR GROUND PENETRATING SYNTHETIC APERTURE RADAR LANDMINE DETECTION

The use of vehicle- or air-borne Ground Penetrating Synthetic Aperture Radar (GPSAR) to quickly detect landmines over large areas is becoming a trend. However, producing too many false alarms in GPSAR landmine detection is a major challenge in practical applications of GPSAR. Support Vector Machine (SVM), employing structural risk minimization theory, does not need large amounts of training data, which makes it suitable for solving the landmine detection problem. In this paper, a novel SVM with a hypersphere instead of a hyperplane classification boundary is proposed for landmine detection in GPSAR. The HyperSphere-SVM (HS-SVM) can be trained with both landmine and clutter data, or with landmine data only, which are called the two-class HS-SVM and the one-class HS-SVM, respectively. The HS-SVM has better generalization capability than the traditional HyperPlane-SVM (HP-SVM) with respect to varying operating conditions. Quantitative comparisons have been made using real data collected with the rail-GPSAR landmine detection system, which show that both the two-class and the one-class HS-SVMs have better detection performance than the HP-SVM.

Fine Geological Radar Processing and Interpretation

Geological radar probing technology finds wide application in engineering projects. The high-precision characteristics of geologic radar should be studied in connection with fine processing and interpretation. This article discusses such issues as (1) geologic radar noise source and (2) fine processing and interpretation of radar data. It is focused on how to achieve fine processing and interpretation.