EFFECT OF WATER DEPTH ON WIND-WAVE FREQUENCY SPECTRUM Ⅰ.SPECTRAL FORM

Wen et al.'s odhed dewiogh to obtain wind-wave frequency spectrum in deep was used toderive the spectrum in finite depth water. The spedrum S(ω) (ω bein angular frequency) when normalizedwith the zeroth moment m and peak frequercyω。 contains in adrition to the peakness factor P=ω。S(ω。)/m。, a twth parameter n=(2πm。)_(1/2)d (d being water depPth), so the spatrum behavior can bestudies for different ware growth stages and water depths.     

珠江口水体叶绿素a浓度高光谱反演研究

对珠江口水体进行了现场光谱测量和同步的水质采样分析,发现695nm处的一阶导数光谱数据对叶绿素a浓度有很好的指示作用,由此建立了基于695nm处一阶导数光谱数据的叶绿素a浓度的线性模式、二次多项式模式、三次多项式模式和指数模式。两次实验的结果表明:指数模式的R2(确定系数)为0.7584,预测平均相对误差为26.7239,是估算珠江口水体叶绿素a的最佳的模式。     

多尺度卫星重力场分解与场源深度关系研究

以直立六面体模型为基础,使用相关分析研究小波基和小波阶数的选取,同时对功率谱深度估计方法进行实验。结果表明,使用恰当的小波基和小波阶数分解重力场,可以获取地层深部信息。计算的南海北部陆缘地区及其范围内珠江口、台西南盆地的莫霍面深度分别为28.3、23.9、20.8 km,与文献资料基本一致。     

波谱模拟模型在遥感中的应用

波谱模拟模型在遥感应用中至关重要，但是传统的波谱模拟模型应用主要是基于单机版的应用，模型模拟的结果不能广泛共享，并且利用波谱数据库的支持也十分有限。试图突破这种局限，以波谱模拟模型在遥感中的应用为主线，参照知识库系统建设的理论，采取B／S的网络结构．充分利用波谱数据库和先验知识库的强大支持，建立分布式波谱模拟模型的应用系统，通过一定的规则和算法自动从波谱数据库和先验知识库中调用数据和知识作为模型的输入参数；对于模拟的结果．可以根据用户意愿决定是否录入波谱数据库，作为知识库系统的知识获取机制，为用户进行遥感应用提供了一个有力的支持平台。     

GENERAL THEORY FOR APPARENT ENERGY DISTRIBUTION OF SEA WAVES

lwrRODUcrIONSeawavesarerecognindasacrucialfaCtorinengineeringandoffshorestruCturede-signsandconstitutCanimPoftantpartintheoreticalstudiesandapplicati0ns.TocopewiththecomPlexityofseawaves,alinearrandomwaveshomogeneousandstationarythe-oryisintrodutalwhereintwomodeIsdescribetheoonnsurfaeedisplacement.Inthefirstone,thesurfaeedisplaerentchangingwithlocationandtheisexpnssedingeneralitalFouriertransform,wherethefrequencyspeCtrumE(co)andwavenumberspodrumEoocanbedefined.Theotherwavemodelisbasedo…     

Some Problems on the Global Wavelet Spectrum

In order to test the validity of the global wavelet spectrum - a new period analysis method based on wavelet analysis, we carried out some simple experiments. In our experiments we used idealized time series and real Nifio 3 sea surface temperature （SST） for testing purposes. First we combined different signals which have the same power but different periods into some new time series. Then we calculated the global wavelet spectra and Fourier power spectra for the testing time series. The testing results revealed that on some occasions the global wavelet spectrum tends to amplify the relative power of longer periods. By making comparisons with the results obtained by the traditional Fourier power spectrum, we demonstrated that on an occasion when the global wavelet spectrum does not work the Fourier power spectrum can be used to achieve the right results. Hence it is recommended that when making period analysis with the global wavelet spectrum one needs to do further tests to confirm their results.     

相位在地震勘探中的用途及研究

主要应用傅立叶变换方法计算各种信号的振幅谱和相位谱。通过对一个球形信号进行傅立叶正反变换，发现用相位谱恢复的图形轮廓比振幅谱恢复的图形轮廓清晰。相位在信号分析中，特别是对于所要研究的地震信号尤为重要。但是，相位谱的常规计算及显示方法很难满足解释要求，就通过改善相位谱的常规计算及显示方法，并用一个简单地震模型例子，说明了改善后的相位谱更容易被解释和利用。     

A proposed frequency spectrum for fully developed wind waves by revisiting P-M spectrum

It is generally believed that the equilibrium range of wind wave spectrum is in the form of the −4 rather than −5 power law. However, in the widely applied P-M spectrum the equilibrium range is given in the form of −5 power law. In the present paper, a spectrum for full development of wind waves is proposed using the form of the Neumann spectrum, but adopting the −4 power law for the equilibrium range. The proposed spectrum has been verified with NDBC buoy data and could be a substitute for the P-M spectrum.     

���ڷ�ƽ��ʱ�����еIJ�ͬ��������ȡ�����Ա��о�

??????????з?????????????????????????????????????????????????????????????????????????в????н????????????????λ???????н?????????????????????????????????????????????????????????????????????????????????????     

固体潮潮汐因子的特征频谱及其应用

本文应用非线性谱分析中的最大熵谱分析方法（ＭＥＭ）、和一般线性功率谱的分析方法，对固体潮潮汐因子的时间序列进行了综合研究，指出固体潮潮汐因子的时间序列中普遍存在明显的半月左右周期的特征频谱；将其应用于地震前兆的分析与探索，对固体潮潮汐因子特征频谱中的前兆变化特征进行了解释，得出结论：半月左右周期的频率域，是固体潮观测中前兆响应的一个重要主频域。     

利用CEEMDAN进行GNSS-MR雪深反演

将自适应噪声的完全集合经验模态分解方法替换常用的二次多项式方法,对原始信噪比（signal-to-noise, SNR）进行信号分解,直接提取相应的本征模态函数,再应用于GNSS-MR技术反演雪深。以美国科罗拉多州NWOT测站GPS数据进行实验的结果表明,该方法与传统方法相比,均方根误差降低30.7%,与实测数据相关系数为0.965,验证了该方法的有效性。     

云南省腾冲油菜反射波谱特征与应用分析

以云南省腾冲县的油菜为例,探讨同种作物在不同生长阶段的光谱特点及其关系,探讨不同盖度情况下的同种作物的光谱特点及其关系。通过野外典型选样测定,并对测定数据进行处理和分析。研究初步表明,在375-670nm的范围内,其反射率随油菜开花量的增加而增加。在800-1100nm的范围内,其反射率随油菜开花量的增加而减少。在800-1100nm范围内,未开花油菜与全开花油菜的组合比例与其光谱组合比例比较接近。在368.4-738.2nm的范围内,盖度越高的菜地,其反射率越低。在741.2-1110.6nm的范围内,盖度越高的菜地,其反射率越高。在500-700nm范围内,土壤与覆盖度为100%的油菜的组合比例与其光谱组合比例比较一致。该研究对不同生长阶段油菜的识别以及不同盖度油菜的识别具有积极的应用意义。     

Parameterized first-guess spectrum method for retrieving directional spectrum of swell-dominated waves and huge waves from SAR images

A method to retrieve ocean wave spectra from SAR images, named Parameterized First-guess Spectrum Method (PFSM), was proposed after interpretation of the theory to ocean wave imaging and analysis of the drawbacks of the retrieving model generally used. In this method, with additional information and satellite parameters, the separating wave-number is first calculated to determine the maximum wave-number beyond which the linear relation can be used. The separating wave-number can be calculated using the additional information on wind velocity and parameters of SAR satellite. And then the SAR spectrum can be divided into SAR spectrum of wind wave and of swell according to the result of separating wave-number. The portion of SAR spectrum generated by wind wave, is used to search for the most suitable parameters of ocean wind wave spectrum, including propagation direction of ocean wave, phase speed of dominating wave and the angle spreading coefficient. The swell spectrum is acquired by directly inversing the linear relation of ocean wave spectrum to SAR spectrum given the portion of SAR spectrum generated by swell. We used the proposed method to retrieve the ocean wave spectrum from ERS-SAR data from the South China Sea and compared the result with altimeter data. The agreement indicates that the PFSM is reliable.     

Wavenumber and depth properties of temperature finestructure in the region around the Ryukyu Islands

INTRODUCTIONTheoceanicfinestructureintheEastChinaSea (ECS)Kuroshioregionhadbeenstudiedbyvariousresearchers.Fangetal.(1 988)studiedthefeaturesofthefinestructureinthesouthernshelfareaandtheKuroshioareaintheECSbyusingCTDdata .Baoetal.(1 996)analyzedsomefeaturesofthermohalinefinestructureandrevealeditsrelationwiththewatermassesandcurrentssysteminthenorthernECS .ButoceanicfinestructureintheeasternregionoftheKuroshiohassel dombeenstudied .Inthispaper,basedon 4 2CTDprofilesgatheredinsum…     

EFFECT OF WATER DEPTH ON WIND-WAVE FREQUENCY SPECTRUM Ⅱ. VERIFICATION AND COMPARISON

The spectrum derived in Part 1 of the presert paper is here systematically verified with field data andcompared at some length with that obtained by multiplying the deep-water spectrum with theKitaigorodskii factor.     

2006年9月秭归泄滩极微震群初步研究

2006年 9月17～22日在秭归泄滩镇西侧发生了一次极微震群活动,其中最大地震为9月20日21时10分 ML1.8级.分析结果表明:本次震群的震中主要集中于泄滩镇老石门村至老泄滩一线,震源深度为海平面以上0.5 km范围内,为正倾滑机制解;该震群频谱最佳频率主要集中在2 Hz左右,初步推断该震群为地表层重力作用下矿塌型地震并伴有几次浅层微滑坡.     

Effect of water depth on wind-wave frequency spectrum II. Verification and comparison

The spectrum derived in Part I of the present paper is here systematically verified with field data and compared at some length with that obtained by multiplying the deep-water spectrum with the Kitaigorodskii factor. Project supported by the National Natural Science Foundation of China.     

Effect of snow-cover duration on plant species diversity of alpine meadows on the eastern Qinghai-Tibetan Plateau

Although snow cover plays an important role in structuring plant diversity in the alpine zone, there are few studies on the relationship between snow cover and species diversity of alpine meadows on the eastern Qinghai-Tibetan Plateau. To assess the effect of snow cover on plant species diversity of alpine meadows, we used ten parallel transects of 60 m × 1 m for this study and described the changes in species diversity and composition associated with snow depth. With the division of snow depth into six classes, the highest species richness （S） and species diversity （H′） occurred with an intermediate snow depth, i.e., class Ⅲ and class Ⅳ, showing a unimodal curve with the increase in snow depth. The relationship between snow depth and plant diversity （both richness and Shannon index） could be depicted by quadratic equations. There was no evident relationship between diversity （both S and H′） and soil water content, which implied that other more important factors influenced species diversity. The patterns of diversity found in our study were largely attributed to freeze-thaw alteration, length of growing season and disturbances of livestock grazing. Furthermore, snow depth affected species composition, as evaluated by the Sorensen＇s index of similarity. In addition, almost all species limited to one snow depth class were found only in class Ⅲand class Ⅳ, indicating that intermediate snow depth was suitable for the survival and growth of many alpine species.     

典型地物波谱库的数据体系与波谱模拟

本文讨论典型地物波谱知识库的数据体系与地物波谱模拟的相关问题 ,并给出波谱知识库支持的农业定量遥感应用示例。波谱知识库的数据体系强调波谱参数与环境参数的配套 ,波谱数据测量是在相关规范的支持下完成的 ,质量控制贯穿于数据采集的全过程。波谱模拟通过遥感物理模型完成 ,模拟波谱计算包括地表参数的时间、空间扩展与遥感物理模型运算。最后以作物生长模型结合植被组分光谱模型和冠层遥感模型为核心 ,构造了定量遥感的农业示例。     

����������׹��Ƶ�GPS����ʱ��������������

?????????????GPS???????У???????????????????????в???db6С??????????????????????????????С????????????????????GPS???????????????????????????????????????????????????GPS?????????????????а???????????????????????????????????????????GPS???????????????????????????????????????????????????к?????????