雷達反射系數 的英文怎麼說
中文拼音 [léidáfǎnshèxìshǔ]
雷達反射系數
英文
radar reflectivity factor- 雷 : 1. (雲層放電時發出的響聲) thunder 2. (軍事上用的爆炸武器) mine 3. (姓氏) a surname
- 達 : Ⅰ動詞1 (暢通) extend 2 (達到) reach; attain; amount to 3 (通曉; 明白) understand thoroughly...
- 反 : Ⅰ名詞1 (方向相背) reverse side 2 (造反) rebellion 3 (指反革命、反動派) counterrevolutionari...
- 射 : Ⅰ動詞1 (用推力或彈力送出) shoot; fire 2 (液體受到壓力迅速擠出) discharge in a jet 3 (放出) ...
- 系 : 系動詞(打結; 扣) tie; fasten; do up; button up
- 數 : 數副詞(屢次) frequently; repeatedly
- 雷達 : [訊] radar (縮自 radio detection and ranging)
- 系數 : [數學] coefficient; ratio; modulus; quotient; factor
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Main conclusions drawn from the analyses of calculating results are as follows : ( 1 ) the microwave absorption of atmosphere gas have obvious attenuation at the wavelengths for cloud detection, thereinto, the water attenuation effect changes greatly, so the 94ghz cloud detecting radar should have water vapor attenuation correction scheme. ( 2 ) when 37ghz and 94ghz radars detect clouds, the difference between the atmosphere and cloud attenuation and the large variety of radar reflectivity conduce the intension of the radar backscatter signals change. ( 3 ) for the thin cloud layer and low water content of cloud, 37 - ghz radar backscatter signals are not as good as 94 - ghz radar, that is to say that the 94ghz radar has better capability in thin clouds detection
本工作得出如下結論: ( 1 )大氣氣體的微波吸收在測雲波段產生明顯的衰減,其中水汽衰減效應變化很大;即將上天的空間94ghz測雲雷達必須有水汽衰減訂正方案; ( 2 ) 37ghz和94ghz雷達測雲,由於大氣和雲衰減不同和雷達反射率的很大差異,導致雷達回波信號強弱不同; ( 3 )對雲層較薄、含水量較少的雲,在不計雷達參數的情況下, 37ghz雷達回波信號不如94ghz測雲雷達,也就是說94ghz對薄雲有更強的探測能力;對雲層較厚、含水量大的雲,由於強衰減的作用, 94ghz雷達回波信號小於37ghz雷達; ( 4 )從大氣衰減的不利因素方面考慮,空間94ghz雷達測高層薄雲的效果最好;測低層薄雲時需要考慮氣體衰減訂正;因濃厚雲的強衰減作用,探測其中下部的能力大大減弱,不僅要進行衰減訂正,而且要藉助其他信息來反演整個雲層的含水量垂直分佈; ( 5 )為了獲得從極薄到極濃厚雲的垂直分佈探測能力,未來測雲雷達系統最好採用雙波長甚至三波長(如94 、 37和13ghz ) 。As for a space - based cloud radar, the change of the radar reflectivity n and the change of attenuation rate along with the cloud liquid water content have been compared between 37 ghz and 94ghz. the transmittance t of single level cloud for different heights and liquid water content has also been calculated at 2 frequencies. by defining a = n tr, which combines both effects of radar reflectivity and transmittance, we have examined the values of a at 37ghz and 94ghz for high, middle and low cloud liquid water contents
對空間測雲雷達,討論了37ghz和94ghz這兩個頻率的雷達反射率和衰減系數隨雲液水含量的變化;計算了不同高度的單層雲在不同頻率,不同含水量情況下的雲層透過率_ ;定義a = _來綜合考慮雷達反射率和透過率對空間測雲雷達回波的影響,分析比較了雲含水量高、中、低時37ghz和94ghz的a值大小。This dissertation bases on the research of battlefield armored reconnaissance tank system, which is a very important reconnaissance & information reception means for our country ? digital armored troops. the zzco2 radar armored reconnaissance tank system is the collector of radio information by use of the radiation and reflection of electromagnetic wave, at the same time it is a system which saves, processes and transmits the radar information picked up. the content of this dissertation involves the design and development of zzco2 ? software system
本論文以我軍裝甲機械化部隊坦克師的戰場裝甲偵察系統的研製為背景撰寫。該系統是我國數字化裝甲部隊的重要偵察和信息獲取工具。其中zzc02型雷達偵察車(型)是該系統的前沿偵察車,是不可見電磁頻段的雷達信息的收集者,是以電磁波輻射、反射作為信息獲取的主要手段,以計算機主機為中心的信息採集、處理、存儲和傳輸系統。For parameter a, there is a close relationship exist between a ( 9, sr ) in two different radar incident angle that can be expressed as : with considering the effects of soil texture, we get the final expression of the inversion model : where mv ( t1 ), mv ( t2 ) is volumetric soil moisture content in two different temp, c, d is soil type related parameters, and v ( t1 ), s ( t2 ) is coresponding bare soil radar backscattering coefficients. inversion results show that for the c band hh polarized radarsat scansar data with a range of incidence angle from 20 to 40, the soil moisture change value can be derived with an acceptable accuracy using the above model. the temporal and spatial soil moisture change patterns are associated with rainfall and vegetation cover, as well as the soil hydraulic characteristics
利用最新發展的電磁波散射模型研究了不同植被覆蓋地表雷達波對地表土壤水分的敏感性,建立了半經驗植被雷達後向散射模型; 2 ) .研究發現在農作物等矮小植被覆蓋地表,植被層直接後向散射與植被類型相關,且在植被生長期,雷達後向散射系數對植被含水量的敏感性要高於對植被高度變化的敏感性; 3 ) .解決了單參數雷達地表土壤水分反演問題中,雷達入射角和地表粗糙度的影響這一難點問題; 4 ) .利用土壤介電模型校正了不同土壤類型對反演地表土壤體積含水量的影響; 5 ) .在以上成果基礎上,建立了完整的單參數雷達地表土壤水分變化探測反演演算法,經地表驗證,模型反演地表土壤水分變化值的精度為rmse = 0Based on rain drop size distribution ( dsd ) data measured in qingdao, guangzhou and xinxiang, the radar reflectivity factor z for spherical rain drops, the radar reflectivity factor zh and differential reflectivity zdr for oblate ellipsoid rain drops have been calculated. the relation of reflectivity and rainfall rate for conventional meteorological radar and the relation of reflectivity, differential reflectivity and rainfall rate for multiparameter radar are regressed, the performance difference of two kinds of radar for measuring rainfall and difference for measuring rainfall in different regions are also discussed
基於我國青島、廣州和新鄉地區雨滴尺寸分佈數據,計算了球形雨滴雷達反射因子,橢球形雨滴雷達水平極化反射因子和差分反射率,回歸給出了這些地區的常規氣象雷達反射因子與降雨率的經驗關系和多參數雷達水下極化雷達反射因子、差分反射率和降雨率關系,並對其測雨精度和地區差異進行了比較。( 2 ). according to the system indices and requirements together with the technology characteristic, it researches the capture possibility of apt capturing system. then it introduces the common scan methods, such as raster, spiral, raster spiral, rose and lissajo. ( 3 ). it makes a detailed simulation analysis of the raster and spiral scan, analyze the connection between capture probability, capture time, system index at different capture resolution angle, capture range, vibration angle extent and terminal location distributing mean square deviation
其中對幾個關鍵部分進行了詳細分析:計算了目標角反射器的激光雷達散射截面( lrcs )值,研究了qd與ccd對目標位置角度的計算方法和空間解析度; ( 2 )根據系統指標和要求並結合現有國內技術特點研究了apt捕獲系統掃描的捕獲概率問題,然後分析了幾種常見的掃描方式:矩形( raster )掃描、螺旋( spiral )掃描,矩形螺旋( rasterspiral )掃描,玫瑰形( rose )掃描以及李薩如形( lissajo )掃描; ( 3 )對分行掃描和螺旋掃描進行了詳細的模擬分析,分析了它們在不同捕獲分辨角、捕獲范圍、振動角振幅和終端位置分佈均方差時的捕獲概率、捕獲時間與系統常數之間的關系。Using a simple radiative transfer model for vegetation volume scattering and the integral equation model ( ibm ) for surface scattering with the field in situ measurements as the input, we compared the simulated and sar measured backscattering coefficients in different agricultural fields
特別是在植被覆蓋地表,對其下土壤水分的監測更帶有極大的困難性。因此,利用雷達後向散射系數反演土壤水分必須首先充分理解微波與地表的相互作用過程。2 ) radar incidence angle and surface roughness correction : to make radar incidence correction and eliminate the surface roughness effects, a wide range of surface parameters ( soil moisture, surface rms height, correlation length, incidence angle ) was input to the ibm model to simulate the effect of surface roughness and radar incidence angle on the sensitivity of soil moisture to the radar backscattering coefficient. a simple model was established to simulate the effects of incidence angle and surface roughness. 3 ) establishment of soil moisture change inversion model : according to a modified ibm model simulation results, the bare surface backscattering coefficients can be expressed as a funtion of the dielectric component for a given surface roughness when the surface slope greater than 2. 0, which is valid for most nature surface : in above equation, r0 is the surface reflectivity at normal incidence
本研究中,首先利用基於微波輻射傳輸方程的微波植被模型和積分方程( iem )模型模擬了各種地表土壤水分含量情況下,植被覆蓋、地表粗糙度(包括地表均方根高度和相關長度) 、雷達入射角對c波段(頻率4 . 7ghz )水平極化( hh )雷達後向散射系數的影響,在此基礎上,建立模型消除了植被覆蓋、地表粗糙度、及雷達入射角對雷達後向散射的影響,利用多時相50m解析度radarsatscansar雷達後向散射系數圖像反演得到了地表土壤水分變化模式信息。This paper contains a useful smmary of log normal distribution, weibull distribution and the k - distribution. the weibull distribution may well extend to phenomena other than radar including radiation scattered from turbulent or rough surface
對雷達波來說,海面是極其復雜的反射體,關鍵是找出一些合適的參數,以便建立一個描述海浪一回波依從關系的數學模型。In this dissertation, first, the basic conceptions of ew, radar ew and combat effectiveness are made clear about internal characteristics, consist and tasks. then, the evaluation factors architecture of radar ew system combat effectiveness is set up, which is the base of quantificational evaluation. second, mathematics modeling of radar ew reconnaissance, radar jamming and anti radiation attack are constructed
本論文的研究首先從電子戰、雷達對抗、武器裝備作戰效能的基本概念出發,理清其內涵、特點、組成、任務,從而建立以能力為主線的雷達對抗系統作戰效能評估指標體系,為定量評估系統作戰效能奠定基礎;然後分雷達偵察、雷達干擾、反輻射攻擊分別對雷達對抗系統武器裝備的電子偵察能力、電子干擾能力、電子進攻能力進行數學建模,進而建立系統綜合對抗能力數學模型,為系統模擬建立設計基礎。分享友人