high frequency spectrum 中文意思是什麼
high frequency spectrum
解釋
高頻光譜-
Toothed species in general employ more of the frequency spectrum, and produce a wider variety of sounds, than baleen species ( though the sperm whale apparently produces a monotonous series of high - energy clicks and little else )
齒鯨一般是用更多頻率並且產生一個廣的變化的聲音，和長須鯨相比（盡管抹香鯨顯然能發出一系列單調的高能咔嚓聲，其他基本不會） 。 -
High frequency ground wave radar for near ocean inspection and ocean remote sensor is a method that use ocean echo wave dopier spectrum to deduce the parameters of ocean situation
高頻地波雷達近海監測和海態遙感技術是一種利用海洋回波多普勒譜反演海態參數的方法。 -
By using ofdm technology, we can redu ce the baud rate with a high frequency spectrum utility factor. another advantage of this technology is that the transmission can combat the intersymbol interference ( isi ) at the receiver without complex adaptive equalizer
Ofdm既有較高的頻譜利用率，也有效地降低了碼速率，在不使用復雜的通道均衡技術的條件下仍然可以較好地克服接收時由多徑效應帶來的碼間串擾（ isi ） 。 -
In this thesis, for the merits of high frequency spectrum utility factor and high - speed data communication, the ofdm is introduced into the underwater acoustic communication. combined with fec to combat the frequency - selective fades and isi in the underwater acoustic channel, high speed data transmission is realized by employing ofdm technology
本研究嘗試將ofdm技術引入水聲通信領域，利用該技術頻譜利用率高，多載波并行傳送的特點，結合通道編碼，以克服水聲通道多徑干擾引起的頻率選擇性衰落和碼間干擾，獲得高速率數據傳輸。 -
Frequency - hopping ( fh ) is a novel spread spectrum communication technique, which develops very fast in military field due to its lpi / lpd ( low probability of intercept / detection ) properties and immunity against interferences, the extensive application of hf ( high frequency ) frequency - hopping radios in military has greatly enhanced the ability of military equipments against jamming and interception and brought up a new austere challenge for communication countermeasures
跳頻通信具有良好的抗干擾性，低截獲概率及組網能力，因此跳頻技術的一出現，便在軍事領域得到了極大的發展，採用跳頻技術的短波電臺在軍事通信中得到了廣泛應用，極大地提高了軍事裝備的抗截獲和抗干擾能力，向通信對抗提出了嚴峻的挑戰。 -
By integrating conventional fourie transformation with the smooth average method of spectrum, the high frequency noise was not only removed, but also the signal was smoothed and the main frequency of the signal was found easily and then was extracted as the coarse features of the signal. on the basis, in order to analyze the detail features of the signal, the signal can be decomposed using the db6 mother wavelet function
在譜分析方法的傅立葉變換中引入平滑平均法對蜂窩結構材料和纖維增強材料聲-超聲檢測信號進行處理，不僅可以有效地去除信號的高頻噪聲，而且可以平滑信號，突出檢測信號的主頻，實現了對檢測信號「粗信息」特徵的提取；在此基礎上，合理選用db6小波基函數，對信號進行小波分解，對信號的特徵進行進一步的細微分析。 -
This article describes a way of special ultrasonic system which monitors thermal stress in seamless welded rails. this monitoring system is a non destructive testing system, which adopts avr mcu and high - precise time chip processing as the core of it, and adopts the critically refracted longitudinal wave as the object of measuring. my studying focuses on the theory of the monitoring system, which will be listed in this arctile : according to the snell theory, the theory of motivating of critically refracted longitudinal wave is described in details, and the finite element software is used to emulate the propagating course. the formulas of calculating the pts of swr are taken from the acoustoelasticity theory, and the calculating the parameters is introduced. according to assemble materials, three kinds of ways of monitoring the pts of swr using critically refracted longitudinal wave are described, which are measuring the sound - time in changeless distance, ultrasonic critical - angle refractomery and frequency spectrum, the first way of ways is used in this experiment system. the factors, which effect the monitoring system, are assaid in some degree based
本文的研究工作重點在無縫焊接鋼軌溫度應力測量系統的理論模塊，包括根據snell原理，研究極限折射縱波的激發機理，並使用有限元軟體ansys進行模擬;根據聲彈性理論以及公式推導出計算無縫焊接鋼軌中的溫度應力的公式，並對其中參數的求解方法進行介紹;根據收集的資料，介紹了三種使用極限折射縱波測量無縫焊接鋼軌溫度應力的方法，即固定距離測量聲時法、臨界角折射法和頻譜分析法，本實驗系統使用的是第一種;根據實驗經驗以及相關資料，分析了影響極限折射縱波測量溫度應力的幾個因素，並提出了相應的解決方法;根據實驗系統的需要，獨立設計並加工出相關配套的實驗設備，包括實驗鋼塊、有機玻璃楔塊、固定件、載荷外框裝置等。 -
On the basis of high speed hybrid filter banks adc system, a kind of downsampler model based on bandpass sampling theorem is presented, and analyzed, proved in time and frequency domain, in addition a downsampler is designed according to the model. a class of high effective hybrid filter banks adc system which bases on the downsampler and radio frequency spectrum is proposed, of which digital signal rate falls m times as fast as the former
作者提出了一種基於帶通采樣定理的抽取器數學模型，對該數學模型進行了時域、頻域的分析證明后，設計了一種基於該數學模型的抽取器，進而根據無線電射頻信號頻譜的特點，提出了高效混合濾波器組adc系統，其數字信號輸出速率比高速混合濾波器組adc系統降低m - 1倍。 -
To this paper we were carried tentatively on spectrum whitening in prestack, and each section after division scale is processed with spectrum whitening, particularly the composition of high frequency is raised apparently, the signal - noise ratio of high frequency raise. the resolution of whole section is better than stack
本文還嘗試性地在疊前進行譜白化處理，對分尺度后的各個記錄分別進行譜白化，尤其是高頻成分提高得很明顯，有效地提高了高頻信噪比，整個剖面的解析度明顯增強。 -
Doing the further research on the division frequency stack on the foundation of study of predecessor, at first the residual moveout correction is done to the seismic record, make the phase axle regularity, doing foundation for the same phase stack ; then carried on division scale processing by wavelet transform ; spectrum whitening is done to each scale, the high and low frequency band need to do prolongs, the middle frequency bands only increase the value of the frequency spectrum ; several kinds of methods that estimate the value of signal - noise ratio has been studied further, and summarize their advantage and disadvantage as well as the scope of application ; the seismic record after spectrum whitening is stacked by weighting with the value of the signal - noise ratio ; then estimate the value of signal - noise ratio which is each scale section after stacking, the scale that the signal - noise ratio is big is assigned big weighting, otherwise, the scale that signal - noise ratio value is small is assigned small weight ing, and carried on weighted reconstruct to each scale section
本文在前人研究的基礎上，在分頻疊加方面做了進一步的研究。首先對地震記錄進行剩餘時差校正，校齊同相軸，為同相疊加做好基礎工作；然後對地震記錄用小波變換的方法進行分尺度處理；對各個尺度分別做譜白化，對于高、低頻段需要做頻帶延拓，中間頻段僅提升頻譜值；對于幾種信噪比定量估計的方法進行了深入的研究，並且總結了它們的優缺點以及適用范圍；對譜白化后的地震記錄用信噪比估計值作為加權系數進行加權疊加；對于各尺度的疊加剖面也進行信噪比估計，對于信噪比大的尺度給予大的加權系數，反之，信噪比值小的尺度給予小的加權系數，對各尺度疊加剖面進行加權重構。 -
Uncertainty principle points out that, which means that high time resolution and high frequency resolution can not be obtained both at the same time in spectrum analysis
測不準原理表明： t ? f 1 / 4 ，即在一次譜分析中，時間解析度和頻率解析度不能同時達到高解析度 -
Through the research of direct digital synthesizer ( dds ) used as a divider in phase lock loop ( pll ), a frequency synthesizer with small frequency resolution ratio and high purity frequency spectrum can be realized
摘要通過對直接數字合成器在鎖相環路中作為分頻器應用的研究，使頻率合成器可以在實現超細頻率解析度的同時達到高的頻譜純度。 -
Impulse wave has been examed on high speed wide frequency spectrum oscillograph, we have a satisfaction result on amplitude, shape, and shot time duration
發射電路經過高速寬帶示波器的輸出測試，得到了比較理想波形和幅度以及納秒級寬度的窄脈沖。 -
As another application instance, a subsystem monitoring ultra - high frequency partial discharge of transformer is developed, which can analyse, process, plot time - domain pd data and demodulated pd data, besides, it also has such discharge type recognition function as spectrum calculation and auto correlation
作為另一應用實例，研製了變壓器超高頻局放監測子系統，此系統具有分析、處理、顯示超高頻時域波形及其包絡線波形數據的功能，還具有用於放電模式識別的時域波形及其包絡線波形的頻譜計算和自相關處理等功能。 -
The mechanism for the fault of the working state of anode is studied in this paper. the spectrum of the sampled signals is got using the technique of amplitude - frequency analysis, then the corresponding iir butterworth digital filter is designed to separate the low - frequency part and the high - frequency part using digital filter design technique
利用頻譜分析技術對采樣信號進行頻譜分析，並採用數字濾波器設計技術設計了相應的r型butterworth數字濾波器，將信號中的低頻信號和高頻組分進行分離，從中提取出與陽極工作故障有關的特徵量。 -
Frequency - hopping ( fh ) is a novel spread spectrum communication technique, which develops very fast in military field due to its lpi / lpd ( low probability of intercept / detection ) properties and immunity against interferences, the extensive application of hf / vhf ( high frequency / very high frequency ) frequency - hopping radios in military has greatly enhanced the ability of military equipments against jamming and interception and ensure the safety and validity of chain of military command
跳頻技術是擴頻技術的一種，是80年代以來出現的一種新的通信方式。跳頻通信具有良好的抗干擾性，低截獲概率及組網能力，因此跳頻技術的一出現，便在軍事領域得到了極大的發展。採用跳頻技術的短波超短波電臺在軍事通信中得到了廣泛應用，極大地提高了軍事裝備的抗截獲和抗干擾能力，保證了軍事指揮系統的安全和有效性。 -
Firstly, according to the characteristic that the doppler frequency shift signal can be approximated as a single sinusoid signal, the extended sinusoid signal retrieval ( pisarenko and esprit ) methods are presented and signal state and measurement formulations are developed, so the kalman filter recursive method is got. the brief introduction of low velocity moving target doppler frequency shift signal wigner - ville transformation and wavelet transformation expression are presented in this paper. secondly, because the clutter is gaussian distribution, cumement and high - order spectrum based methods are presented and the simulation results prove their good performance to suppress gaussian clutter in low velocity moving target doppler frequency shift signal processing
一個方面是根據低速目標的多普勒信號可簡化為單一正弦波形式這一特點，得到了擴展的高斯色噪聲背景下的諧波恢復演算法，即高斯色噪聲中的pisarenko諧波恢復法和旋轉因子不變法（ esprit ） ；並推導了信號的狀態方程和觀測方程，進而得到基於卡爾曼濾波的遞推演算法對信號進行提取；本文還簡單的介紹了低速運動目標的多普勒頻移信號的wigner - ville變換與小波變換；另一個方面是針對雜波服從高斯分佈這一特點，提出了對接收信號求累積量和高階譜來對高斯雜波進行抑制。 -
High - frequency spectrum behavior of laser scintillation in turbulent atmosphere
激光大氣閃爍的高頻譜特性 -
The system is compatible with the various different types a / d converters, carry out the functions of the vibration signal sampling, the saving of data file, the timely wave showing, the configuration table edit, the former data return and data analysis etc. the functions of signal analysis include the time field statistics analysis, the time field mutual analyzing, the frequency spectrum analyzing, the relevant analysis, the transmission function analysis, the demodulating analysis, and the short fourier transformation of the time and frequency field etc. experiments verify that the system carry out stably and credibility, various functions is achieved, has precise analyzing results, high calculating speed and high precision, the expected targets have been reached
該系統可以兼容多種不同型號的數據採集設備，實現了振動信號的採集、數據文件的存儲、波形的實時顯示、組態表編輯、歷史數據回放與數據分析等功能。系統的信號分析功能包括時域統計分析、時域相關分析、頻譜分析、相干分析、傳遞函數分析、解調分析以及時頻分析中的短時傅立葉變換等。經試驗驗證表明，系統運行穩定可靠，各項功能工作正常，數據分析結果準確、運算速度快、精度高，達到了預期設計目的。 -
In hf ( high frequency ) radar, the targets detected based on the spectrum processed by the two - dimension fft are peak - like, which makes the operator distinguish them from the clutter and background noise easiler in the 3d ( three - dimension ) display than the 2d
特別對于距離分辨力低的高頻雷達系統，其探測的目標通常近似為點目標，在經二維傅立葉變換得到的頻譜數據上呈現峰狀結構。
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