Connect public, paid and private patent data with Google Patents Public Datasets

Method for determining sandy soil moisture content based on low-frequency ground penetrating radar ground method

Info

Publication number
CN101915771A
CN101915771A CN 201010272467 CN201010272467A CN101915771A CN 101915771 A CN101915771 A CN 101915771A CN 201010272467 CN201010272467 CN 201010272467 CN 201010272467 A CN201010272467 A CN 201010272467A CN 101915771 A CN101915771 A CN 101915771A
Authority
CN
Grant status
Application
Patent type
Prior art keywords
soil
ground
method
content
radar
Prior art date
Application number
CN 201010272467
Other languages
Chinese (zh)
Other versions
CN101915771B (en )
Inventor
信秀丽
张佳宝
朱安宁
Original Assignee
中国科学院南京土壤研究所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Abstract

The invention relates to a method for determining the sandy soil moisture content based on a low-frequency ground penetrating radar ground method, which comprises the determining steps of: collecting ground penetrating radar data by utilizing a together-midpoint method to ensure the travel time of airwaves and ground waves; collecting the radar wave information of a soil section by utilizing a constant spacing method; calculating the dielectric constant of soil; substituting parameters to a formula to obtain the dielectric constant of soil; calculating the water content of soil; substituting the obtained soil dielectric constant epsilon to the formula theta=-5. 3*102+2.92*10-2epsilon-5.5*10-4epsilon2+4.3*10-6epsilon3 to obtain the soil water content. The method for determining the sandy soil moisture content based on a low-frequency ground penetrating radar ground method is suitable to the measurement of the soil water content in farmlands and small river basins, has the advantages of convenience, quick operation, high accuracy and no destruction and is especially suitable to the water content determination of sandy soil.

Description

基于低频探地雷达地波法的测定砂质土壤含水量的方法 The method of determination of sandy soil to a low frequency wave GPR Method Water Content

一、技术领域 First, the technical field

[0001] 本发明涉及一种砂质土壤剖面含水量测定方法,特别涉及一种基于低频探地雷达地波法的测定砂质土壤含水量的方法。 [0001] The present invention relates to a cross-sectional sandy soil moisture content measuring method, particularly to a method based on measurement sandy soil GPR low water content of the ground wave method.

二、背景技术 Second, the technical background

[0002] 长期以来,小尺度的土壤含水量的测定方法主要是烘干法、中子法、传感器法以及时域反射仪法,这些方法能较准确地测定土壤含水量,但都存在着耗时费力并对土壤具有一定的破坏性等问题。 [0002] For a long time, a method for measuring soil moisture content is mainly small-scale drying method, the neutron method, the sensor method and the time domain reflectometry method, these methods can measure soil moisture accurately, but there are significant consumption time-consuming and destructive soil has some other issues. 上世纪90年代中期,遥感技术开始应用于区域尺度上的土壤水分测定,该方法能快速测定区域乃至全球的土壤表层含水量,信息量大,但是,遥感法的空间分辨率较低,而且通过遥感数据只能估计表层0. 05m深度的土壤含水量,受植被覆盖的影响也较大。 In the mid-1990s, remote sensing technology began to be used for determining soil moisture on a regional scale, which can be rapid determination of moisture content of the soil surface region and the world, large amount of information, however, the spatial resolution remote sensing method is low, but also through Remote sensing data can only be estimated 0. 05m depth of the surface soil moisture, vegetation cover affected as well. 由此可见,在确定土壤含水量的时域反射仪方法和遥感方法之间,存在一个空间尺度上的技术空白,即在农田和小流域等中小尺度上,上述方法已经远远不能满足日益发展的土壤科学研究和现代化精准农业对大量、快速、准确的农田土壤水分动态信息的需求。 Thus, between the time domain reflectometry method and remote sensing methods to determine the moisture content of the soil, there is technology on a scale blank space, namely on the small-scale farms and small watersheds, the above method has been far from meeting the growing soil science and modernization of a large number of accurate, rapid, accurate demand information soil water dynamics of agriculture right. 因而,发展科学依据充分的适用于农田和小流域的方便、快捷、准确、无破坏性的土壤含水量测定技术是一个需要重视和亟待加强的问题。 Thus, the development of scientific evidence sufficient farmland suitable for convenience and small watersheds, fast, accurate, and technology is a need to focus on the urgent need to strengthen the problem of non-destructive determination of soil water content.

[0003] 探地雷达技术通过获取雷达波在土壤中的运行信息来估计土壤的介电常数,进而利用土壤介电常数和土壤含水量的经验公式或半理论关系式来计算土壤的含水量。 [0003] GPR techniques to estimate the dielectric constant of the soil by running information obtaining radar waves in the soil, and then calculating the water content of soil and the empirical formula of soil dielectric constant soil moisture or semi-theoretical formula. 现有的探地雷达探测土壤含水量的方法按电磁波传播的类型分类主要有4种:反射波法、地波法, 反射系数法以及钻孔雷达法。 The conventional method of detecting of soil moisture by the electromagnetic wave propagation type classification There are four main kinds: reflection method, the wave method, reflection coefficient, and borehole radar method. 其中地波法根据发射和接收天线距离以及探地雷达测定的地波运行时间来确定浅层土壤含水量,是目前认为具有潜力的土壤含水量测定方法。 Wherein the determination of the wave transmitting and receiving antenna according to the distance and GPR ground wave transit time determining shallow soil moisture, the soil is considered to have the potential moisture content measuring method.

[0004] 目前,国际上应用地波法探测土壤含水量时采用的电磁波频率主要范围为225MHz〜900MHz。 [0004] At present, the main frequency of electromagnetic waves used in the scope of the international application to the soil moisture content is detected wave law 225MHz~900MHz. 而由于低频电磁波的分辨率低,受土壤质地、含水量等影响,雷达图像中不易识别出空气波和地波,目前国内外关于低频探地雷达地波法的研究还较少。 And due to the low resolution of the low-frequency electromagnetic waves, the affected soil texture, moisture content, etc., is not easy to identify the radar images and ground wave air wave, the low frequency current researches on the ground penetrating radar wave method is also less. 但低频电磁波较之高频电磁波具有穿透能力增加,探测深度大等特点,研究层次较深和湿度高的土壤剖面的含水量具有优势。 But compared to the low-frequency electromagnetic wave frequency electromagnetic waves have increased penetrating power, probing depth and other characteristics, moisture content research and high humidity levels deep soil profile has advantages. 低频探地雷达地波法尤其适用于农田土壤含水量测定。 Low-frequency ground penetrating radar to Bofa You it applies to farmland soil moisture measurement.

[0005] 而地波法探测土壤含水量的模式主要有共中点法和固定间距法。 [0005] Method and ground wave detecting soil moisture model with a common midpoint and mainly a constant pitch method. 共中点法作为一种变天线间距方法,测定结果精确性高,但需耗费大量的时间和人力,不适合在较大范围内(IOm-IOOOm)应用。 As an alternative method common midpoint antenna separation method, measurement results of high accuracy, but need to spend a lot of time and effort, is not suitable in a wide range (IOm-IOOOm) applications. 固定间距法具有快速、实时监测的优点,适合于较大尺度的土壤水分时空分布监测,但必须在已知反射界面深度的条件下进行的。 Constant pitch method is fast, the advantages of real-time monitoring, soil moisture temporal distribution suitable for monitoring large scale, but must be carried out under conditions known in the depth of the reflecting interface. 将共中点法与固定间距法相结合来测定土壤含水量,则省时省力的多。 The common midpoint method to determine soil moisture and Combination of fixed pitch, when the province more effort. 先通过共中点法获取不同天线间距的地波走时,然后选择一个能分离出空气波和地波的最佳天线间距,再利用固定间距法探测含水量。 To obtain different ground wave antenna spacing away, can be isolated and then choose a preferred antenna ground wave and air wave pitch, the pitch is fixed reuse water content detection method by common midpoint method. 该方法的最大局限性在于,共中点法与固定间距法的最佳天线间距不统一。 This method is limited in that the maximum total midpoint method and the best antenna fixed pitch spacing is not uniform. 共中点法测定雷达图像中,天线间距越小,图像中的空气波和地波越接近,界面不清晰,难以拾取准确的空气波和地波;而固定间距测定雷达图像中,天线间距越大,雷达波信号越弱,异常信号增多,误差越大。 Determination of radar images common midpoint method, the antenna spacing the smaller the air waves and the image waves closer to the interface is not clear, it is difficult to accurately pick the air wave and ground wave; fixed pitch measured in radar images, the antenna spacing large, weaker radar signals, the abnormal increase in the signal, the greater the error. 因此,如何找到兼顾共中点法和固定间距法的最佳天线间距尤为关键。 Therefore, how to find the optimal antenna spacing of both law and common midpoint fixed pitch method is particularly critical.

[0006] 因此,本方法通过低频探地雷达利用共中点法和固定间距法相结合测定灌水前后的不同土壤含水量,为今后低频探地雷达在土壤学中的进一步应用提供依据。 [0006] Accordingly, the present method and methods common midpoint fixed pitch Combination of different soil moisture measurement before and after the irrigation, provide the basis for the further application of a low frequency GPR in Soil Science use low-frequency GPR.

三、发明内容 III. SUMMARY OF THE INVENTION

[0007] 发明目的:本发明针对上述现有土壤含水率测定方法中存在的不足,提供一种适用于农田和小流域的方便、快捷、准确、无破坏性的土壤含水量测定方法,该方法尤其适用于砂质土壤的含水率测定。 [0007] The object of the invention: The present invention is directed to determination of moisture content less than the above conventional method of soil present, provides a convenient one for agricultural and watershed, fast, accurate, non-destructive method for measuring soil moisture, the method especially for sandy soil moisture content determination.

[0008] 技术方案:基于低频探地雷达地波法的测定砂质土壤含水量的方法,测定步骤为: 通过共中点法采集探地雷达数据,以确定空气波和地波走时:发射天线和接收天线按固定步长沿着测线向相反方向对称地移动,保持一个共中心点,其雷达记录为天线间距与雷达波的走时关系,获取能清晰分离出空气波和地波的不同天线间距X对应的空气波走时tAW和地波走时tew,回归获取tAW〜χ和tew〜χ关系式;以固定间距法采集土壤剖面的雷达波信息:保持探地雷达发射天线和接收天线的间距不变,按固定步长沿着测线方向同时移动的获取雷达图像的测定方法,其雷达图像记录为测线与雷达波走时关系,根据tAW〜χ和tew〜 X关系式计算出固定间距最佳天线间距时的tAW和tew ;土壤介电常数的计算:将参数代入公 [0008] Technical Solution: The method of determination of sandy soil low GPR ground wave method based on the water content, measured steps of: GPR acquisition method by common midpoint data, and to determine the air wave traveltime: transmit antenna and receiving antennas moved in fixed steps along the survey line symmetrically opposite directions, holding a common center point, which is recorded away radar antenna spacing relationship radar wave, the acquisition can be clearly separated air wave and ground wave different antennas when the pitch of the air wave and ground wave to go down tAW tew X corresponding to the return and obtain tAW~χ tew~χ relationship; radar cross section information collection in the soil at a constant pitch method: holding GPR transmit and receive antennas is not a pitch change, according to a fixed step while moving the measuring method of acquiring a radar image along the line direction, which is measured radar image recording radar take the relationship line, the fixed pitch is calculated according to the optimum relationship tAW~χ and tew~ X and when tAW tew antenna spacing; calculating the dielectric constant of soil: substituting the parameters into well

(c\2 (c(t -t UxY (C \ 2 (c (t -t UxY

式得土壤的介电常数 Have a dielectric constant of soil type

其中地波速率V、地波走时tew、空气 Wherein when the wave velocity V, the wave travel tew, air

、vj Iv X J, , Vj Iv X J,

波走时tAW、天线间距X、C为电磁波在真空中的速度0. 3m .ns-1 ;土壤含水量的计算:将计算得到的土壤介电常数ε 代入θ = -5. 3Χ 1(Γ2+2· 92Χ 1(Γ2 ε -5. 5Χ 1(Γ4 ε 2+4. 3Χ 1(Γ6 ε 3,得 Traveltime tAW, antenna interval X, C is the speed of electromagnetic wave in vacuum 0. 3m .ns-1; soil water content calculation: The calculated dielectric constant ε soil substituting θ = -5 3Χ 1 (Γ2 +. 2 · 92Χ 1 (Γ2 ε -5. 5Χ 1 (Γ4 ε 2 + 4. 3Χ 1 (Γ6 ε 3, to give

土壤含水量。 Soil water content.

[0009] 共中点法确定空气波和地波走时的具体步骤为:测线长选择15m至20m,发射和接收天线的起始位置在测线中点南北各IOcm处,起始间距20cm,采集步长20cm,即两个天线每次各沿测线向外移动10cm。 [0009] common midpoint method to determine the specific steps of the air wave and ground wave to go to: select line length measuring 15m to 20m, the starting position of transmit and receive antennas at the measuring points in the line at the north and south IOcm, starting pitch 20cm, acquisition step 20cm, i.e. two per each antenna moves outwardly along the survey line 10cm.

[0010] 有益效果:方法中采用相对低频电磁波较之高频电磁波具有穿透能力增加,探测深度大等特点,研究层次较深和湿度高的土壤剖面的含水量具有优势。 [0010] Advantageous Effects: The method of using a relatively low frequency than high frequency electromagnetic waves have an increased penetration depth of investigation and other characteristics, and the water content were high humidity level deeper soil profile has advantages. 该方法将共中点法与固定间距法相结合来测定土壤含水量,省时省力;适用于农田和小流域的方便、快捷、准确、无破坏性的土壤含水量测定,并通过多条测线测定可以获得土壤剖面连续的含水量变化情况,即土壤含水量的三维分布情况,是对定点测定仪器的补充和扩展。 This method measured total soil moisture midpoint Combination with fixed pitch, time-saving; suitable for agricultural and watershed convenient, fast, accurate, non-destructive determination of the water content of the soil, and by a plurality of sensing lines can be obtained continuously measuring water content of the soil profile changes, i.e., the three-dimensional distribution of the water content of the soil, is designated the complement and extend the measuring device. 另外,通过实验证明,在不同的含水量水平下,该方法都可以得到较为准确的测定结果。 In addition, experiments show that, at different levels of moisture content, which method can give more accurate measurement results.

四、附图说明 IV BRIEF DESCRIPTION

[0011] 图1天线间距-电磁波走时图; [0011] FIG. 1 antenna spacing - FIG wave travel time;

[0012] 图2为砂质土壤初始㈧和灌水处理⑶的固定间距法测定图像(X = Im);其中图2-A为试验初始(未灌水)状态的土壤含水量基本一致,其探地雷达图像为水平直线;图2-B为灌水后,从测线5m处起,灌水区域由于含水量增大导致介电常数增大,从而导致地波的走时tew增大,探地雷达图像渐渐下凹。 Determination of the image [0012] FIG. 2 is a sandy soil, and irrigation treatments (viii) an initial fixed pitch ⑶ method (X = Im); FIG. 2-A which is substantially consistent with the initial test (not irrigation) soil moisture status, which Penetrating a radar image is a horizontal line; FIG. 2-B after irrigation, at 5m from the survey line, due to the increased water content results in irrigation area increases the dielectric constant, resulting in increased tew ground wave travel time, the image gradually GPR concave.

五、具体实施方式 V. DETAILED DESCRIPTION

[0013] 实施例1 :[0014] 1、试验仪器 [0014] 1, test apparatus: [0013] Example 1

[0015] 经过试验,50MHz的天线由于频率太低,不能检测到雷达地波信号,所以本方法采用天线频率为100MHz。 [0015] After testing, the antenna because the frequency of 50MHz is too low to detect radar wave signal, the method employing an antenna frequency 100MHz. 试验采用瑞典Mala GeoScience公司生产的RAMAC/GPR CUII通用主机系统采集数据,主要部件包括:两对频率分别为IOOMHz的非屏蔽接收和发射天线(通过光缆连接到主机)、IOOMHz的屏蔽天线、主机、电脑、光缆和其他配件。 Test Swedish Mala GeoScience produced RAMAC / GPR CUII general host system data collection, the main components including: two pairs of frequencies are IOOMHz unshielded receiving and transmitting antennas (connected to the host through a cable), IOOMHz shielded antenna, the host, computers, cables and other accessories. 采集软件为RAMACGroundvision,图像滤波处理采用REFLEXW软件。 REFLEXW acquisition software using software RAMACGroundvision, the image filter processing.

[0016] 2、试验步骤 [0016] 2, Test Procedure

[0017] (1)通过共中点法采集探地雷达数据,以确定空气波和地波走时。 [0017] (1) data collection GPR common midpoint method to determine the air waves and ground waves away. 即发射天线和接收天线按固定步长沿着测线向相反方向对称地移动,保持一个共中心点,其雷达记录为天线间距与雷达波的走时关系。 I.e., transmit and receive antennas according to a fixed step along a survey line in opposite directions symmetrically moved, maintaining a common center point, which travel record relationship radar antenna and radar wave pitch. 测线长选择15m至20m,发射和接收天线的起始位置在测线中点南北各IOcm处,起始间距20cm,采集步长20cm,即两个天线每次各沿测线向外移动10cm。 Measuring length selection line 15m to 20m, the transmitting and receiving antennas at the measuring points in the line start position of the north and south IOcm, the starting pitch 20cm, 20cm long acquisition step, i.e. two per each antenna moves outwardly along the survey line 10cm .

[0018] (2)以固定间距法采集土壤剖面的雷达波信息。 [0018] (2) radar information collected soil profile method at fixed intervals. 固定间距法即保持探地雷达发射天线和接收天线的间距不变,按固定步长沿着测线方向同时移动的获取雷达图像的测定方法,其雷达图像记录为测线与雷达波走时关系。 I.e., to maintain a constant pitch method GPR transmit and receive antennas of the pitch change method of measuring a fixed radar images acquired step while moving along the line direction, which is recorded an image sensing radar and radar line take the relationship. 此处我们可以采用MALA公司的屏蔽天线(发射天线和接收天线间距为Im),可以方便地获取测线处的雷达信息。 Here we can use the company's MALA shielded antenna (transmitting antenna and receiving antenna spacing Im), you can easily access the measured line of radar information. 采用固定间距法以20cm步长探测整条测线。 Fixed pitch detection method to the entire length of 20cm steps seismic line.

[0019] (3)探地雷达图像处理与解译。 [0019] (3) GPR image processing and interpretation.

[0020] 原始的雷达图像需经过处理才能进行图像的判读、解译及目标体识别,从而获得更精确的目标信息。 [0020] The original image subject to processing radar to perform interpretation of the image, the target recognition and interpretation, so as to obtain more precise target information. 采用ReflexW4.0软件进行预处理,基本步骤为:①去直流漂移;②静校正;③增益;④抽取平均道;⑤巴特沃斯带通滤波;⑥滑动平均。 ReflexW4.0 pretreatment using software, the basic steps as follows: ① to DC offset; ② statics; ③ gain; ④ extracting average channel; ⑤ Butterworth band-pass filter; ⑥ moving average.

[0021] (4) 土壤含水量的计算 [0021] (4) Calculation of soil moisture

[0022] 雷达波在土壤中的传播速度主要由土壤的相对磁导率和介电常数决定,由于在大多数土壤(低盐)的相对磁导率近似为1,地波速率主要受土壤的介电常数控制,通过空气波和地波的走时差可以计算出地波的速度V,从而得到土壤的介电常数: [0022] The velocity of radar wave propagation in the soil and the permittivity mainly determined by the relative permeability of the soil, since the relative magnetic permeability in most soils (salt) is approximately 1, mainly due to the wave velocity of the soil controlling the dielectric constant can be calculated by the ground wave and air wave residuals ground wave velocity V, whereby the dielectric constant of the soil:

[0023] [0023]

[0024] 公式(1)中,c为电磁波在真空中的速度(0. 3m · ns-1)。 [0024] Equation (1), c is the speed of electromagnetic waves (0. 3m · ns-1) in vacuum. 地波走时tew、空气波走时tAW、天线间距χ可通过REFLEXW4. 0软件读取。 When the wave travel tew, the air wave traveltime tAW, can be read by the antenna spacing χ REFLEXW4. 0 software.

[0025] 本研究中首先采用共中点法获得探地雷达图像,获取能清晰分离出空气波和地波的不同天线间距(X)对应的空气波走时(tAW)和地波走时(tffl),回归获取tAW〜χ和〜 χ关系式。 [0025] In this study, firstly using common midpoint method obtained ground penetrating radar images, acquired clearly separate different antenna spacing of the air wave and ground wave (X) of the time corresponding to the air wave travel time (TAW) and the traveltime (tffl) return and get tAW~χ ~ χ relationship. 再根据tAW〜χ和tew〜χ关系式计算出屏蔽天线最佳间距时的tAW和tew,然后, 反推得出土壤的介电常数。 The recalculation of the relationship tAW~χ and tew~χ tew tAW and when shielded antenna optimum spacing, and then, the dielectric constant of reverse thrust derived soils. 土壤的介电常数和含水量紧密相关,证实可以通过测定土壤介电常数,再利用θ〜ε关系式精确地计算土壤体积含水量。 Closely related to soil water content and dielectric constant, it can be confirmed by measuring the dielectric constant of the soil, and then accurately calculated using the volumetric water content of soil θ~ε relationship. 并提出了如下的经验关系式: And made the following empirical relationship:

[0026] θ = -5. 3 X 1(Γ2+2· 92 X 1(Γ2 ε -5. 5 X 1(Γ4 ε 2+4. 3 X 1(Γ6 ε 3 (2) [0026] θ = -5. 3 X 1 (Γ2 + 2 · 92 X 1 (Γ2 ε -5. 5 X 1 (Γ4 ε 2 + 4. 3 X 1 (Γ6 ε 3 (2)

[0027] 由公式(1)、(2),可得土壤含水量。 [0027] by equation (1), (2), available soil moisture.

[0028] 3、该方法测定土壤含水量精度 [0028] 3, the method for determining the accuracy of soil moisture

[0029] 为验证探地雷达对土壤含水量的预测结果,在黄淮海平原豫北封丘地区进行验 [0029] To verify the predictions ground penetrating radar on soil moisture content, to carry out inspection in the North China Plain region in northern Fengqiu

5证,该地区土壤多为在黄河沉积物上发育的潮土。 5 permits, soil development in the region, mostly in the Yellow River sediment Chao soil. 试砂质土壤层厚1. 5m以上,粘粒含量4. 59%,粉粒含量1. 69%,砂粒含量93. 72%,地表无植被覆盖。 Sandy soil layer thickness of the sample than 1. 5m, clay content 4.59%, 1.69% silt content, sand content of 93.72%, the surface unvegetated. 砂壤土层厚Im以上,粘粒含量12. 96%,粉粒含量10. 17%,砂粒含量75. 75%,地表l_2cm处有少量植被覆盖。 Im more loam layer thickness, clay content of 12.96 percent, 10.17 percent silt content, sand content of 75.75%, a small amount of the surface l_2cm vegetation cover. 试验中在测线一侧Im处开挖长1. 5m、深1. 5m的剖面,在剖面上选择距地表10cm、40cm、70cm、 100cm和130cm5个深度,在每个深度上随机选取5个点用TDR100便携式土壤水分测定仪测定土壤含水量。 Excavation long test measured at the line side Im 1. 5m, 1. 5m deep sectional view, in cross-section selected 10cm above the surface, 40cm, 70cm, 100cm and 130cm5 depths, 5 randomly selected at each depth point tester soil moisture by using TDR100 portable soil moisture.

[0030] 共中点法_固定间距法测定砂质土壤含水量 [0030] Determination of sandy soil moisture were fixed pitch midpoint method _

[0031] 首先采用共中点法获得探地雷达图像,获取几个能清晰分离出空气波和地波的不同天线间距对应的地波和空气波走时,如图3所示。 When [0031] First, using the midpoint method were obtained ground penetrating radar images, can be clearly separated obtain several different wave antenna spacing and the air wave and air wave corresponding to the wave travel, as shown in FIG. 共中点法测定雷达图像中地波和空气波均为天线间距χ和走时t的线性关系,回归获取tAW〜χ和〜χ关系式。 When t linear antenna spacing χ and are co-down assay midpoint ground wave radar images and the air wave, regression and obtaining tAW~χ ~χ relationship.

[0032] tAW = 3. 71*χ+0· 60,R2 = 0. 997 (3) [0032] tAW = 3. 71 * χ + 0 · 60, R2 = 0. 997 (3)

[0033] tGW = 6. 97*χ+1· 70,R2 = 0. 996 (4) [0033] tGW = 6. 97 * χ + 1 · 70, R2 = 0. 996 (4)

[0034] 根据(3)式,当天线间距χ = Im时,空气波走时tAW = 4. 31ns。 [0034] According to (3), when the antenna spacing χ = Im, the air wave travel tAW = 4. 31ns.

[0035] 在测线5_9m处布置灌水区域后,采用固定间距法探测整条测线,天线间距设置为Im0试验初始(未灌水)状态的土壤含水量基本一致,其探地雷达图像为水平直线,探地雷达图像如图4(左)所示。 [0035] After measuring line arranged at 5_9m irrigation area, fixed pitch detection method the entire measuring line, antenna interval is set to an initial test Im0 (not irrigation) consistent soil moisture status, which GPR horizontal line images GPR image shown in Figure 4 (left). 灌水后,从测线5m处起,灌水区域由于含水量增大导致介电常数增大,从而导致地波走时tew增大,探地雷达图像渐渐下凹,如图4(右),随着发射天线和接收天线都进入灌水区域,双程走时逐渐稳定。 After irrigation, measured from the starting line 5m, irrigation region since the dielectric constant results in increased water content increased, resulting in increases tew ground wave away, GPR image gradually depressed, as shown in FIG 4 (right), with both transmit and receive antennas into the irrigation zone, gradually stabilized TWT. 由于空气波走时tAW不受土壤含水量变化的影响而保持不变,因此根据固定的天线间距χ与空气波走时tAW,并采用REFLEXW软件读取灌水区域相应的地波走时tew,由公式(1)、(2)计算出土壤含水量。 Since the water content is not affected by changes in TAW soil and air wave travel remains unchanged, and therefore fixed in accordance with the antenna interval χ airwave TAW away, and using the software reads the corresponding irrigation REFLEXW region when the waves go TEW, by the formula (1 ), (2) to calculate the soil moisture.

[0036] 表1共中点-固定间距法测定灌水前后砂质土壤含水量 [0036] Table 1 common mid - Determination of constant pitch in sandy soil moisture content before and after irrigation

[0037] [0037]

[0038] 表1为共中点法_固定间距法测定的灌水前后砂质土壤含水量。 [0038] Table 1 shows the measurement method were fixed pitch midpoint method _ sandy soil moisture before and after irrigation. 由表1可以看出,未灌水条件下,共中点法_固定间距法测得砂质土壤剖面平均含水量在天线间距Im时为6. 5%,TDR测得0-50cm深度处砂质土壤剖面平均含水量为6. 3%。 As can be seen from Table 1, it is not under irrigation conditions, to give a total of sandy soil _ midpoint fixed pitch measurement method when the cross-sectional average moisture content of antenna spacing Im 6. 5%, TDR measured at a depth of 0-50cm sandy The average moisture content of the soil profile was 6.3%. 因此在未灌水条件下,共中点法-固定间距法的测值与TDR测值相比,绝对误差分别为0. 2%。 Thus in a non-irrigation conditions, common midpoint method - the measurement value as compared with a fixed pitch Method TDR measurement value, the absolute error is 0.2%, respectively. 灌水条件下, 共中点法-固定间距法测得砂质土壤剖面平均含水量在天线间距Im时为20. 2%,TDR测得0-50cm深度处的砂质土壤剖面平均含水量为19.7%。 Under irrigation conditions, common midpoint method - a fixed pitch in sandy soil profile as measured at the antenna interval average moisture content of 20.2% Im, TDR sandy soil profile measured at a depth of 0-50cm average moisture content of 19.7 %. 因此在灌水条件下,共中点法-固定间距法的测值与TDR测值相比,绝对误差分别为0. 5%。 Therefore, in irrigation conditions, common midpoint method - the measurement value as compared with a fixed pitch Method TDR measurement value, the absolute error is 0.5%, respectively.

[0039] 结果表明,在不同的含水量条件下,共中点法-固定间距法测得含水量结果都较为精确,可以用于砂质土壤的含水量监测。 [0039] The results show that, under different conditions of water content, co midpoint - fixed pitch measured by the water content of the results are more accurate, can be used to monitor the water content in the sandy soil.

[0040] 通过获取共中点法图像中能清晰分离出空气波和地波的不同天线间距对应的tAW 和tew,回归获取tAW〜X和tew〜X关系式,再计算出屏蔽天线间距Im时的tAW和,兼顾了固定间距法和共中点法法的最佳天线间距,与直接由共中点法最佳天线间距3m进行的固定间距法测量相比,结果更精确。 [0040] Total midpoint image acquired through different antennas can be clearly separated and spacing of the air wave corresponding to the ground wave and TEW tAW, regression and obtaining tAW~X tew~X relationship, and then calculate the shielded antenna spacing Im the tAW and, taking into account the best antenna fixing method and co pitch spacing method midpoint method, as compared with a fixed pitch measured directly by a method best antenna spacing 3m common midpoint method, the more accurate the results. 值得一提的是,目前对于探地雷达探测深度的精确确定仍然是一个难题,还需要展开大量的基础性研究工作。 It is worth mentioning that, for an accurate determination of the current ground penetrating radar detection depth is still a problem, but also need to expand a lot of basic research.

[0041] 4、该方法的应用 [0041] 4. The application of the method

[0042] 1、本方法适于测定砂质土壤含水量,而对于其他质地土壤由于雷达波衰减严重, 测定结果尚需改进; [0042] 1, the present method is suitable for determination of sandy soil moisture, soil texture and other severe attenuation due to the radar wave, the measurement results still need improvement;

[0043] 2、适于质地较均一的土壤; [0043] 2, a uniform texture is adapted to the soil;

[0044] 3、可以用于土壤剖面的土壤含水量监测; [0044] 3, it can be used to monitor the soil water content of the soil profile;

[0045] 4、可以用于研究土壤含水量的空间变异情况。 [0045] 4, it can be used to study the spatial variation of soil water content.

[0046] 实施例2 : [0046] Example 2:

[0047] 基于低频探地雷达地波法的测定砂质土壤含水量的方法,测定步骤为:通过共中点法采集探地雷达数据,以确定空气波和地波走时:发射天线和接收天线按固定步长沿着测线向相反方向对称地移动,保持一个共中心点,其雷达记录为天线间距与雷达波的走时关系,获取能清晰分离出空气波和地波的不同天线间距X对应的空气波走时tAW和地波走时tGff,回归获取tAW〜χ和〜χ关系式;以固定间距法采集土壤剖面的雷达波信息:保持探地雷达发射天线和接收天线的间距不变,按固定步长沿着测线方向同时移动的获取雷达图像的测定方法,其雷达图像记录为测线与雷达波走时关系,根据tAW〜X和〜X关系式计算出固定间距最佳天线间距时的tAW和; 土壤介电常数的计算:将参数代入公式得土 [0047] The method for measuring low sandy soil GPR ground wave method based on the water content, measured steps of: GPR acquisition method by common midpoint data, and to determine the air wave traveltime: transmitting and receiving antennas fixed along the survey line step moving symmetrically in opposite directions, holding a common center point, which is recorded radar antenna spacing and down relationship radar acquires clearly different antennas separated ground wave and air wave corresponding to the distance X when the air wave and ground wave to go down tAW TGFF, regression and obtaining tAW~χ ~χ relationship; radar cross section information collection in the soil at a constant pitch method: holding pitch GPR transmit and receive antennas are constant, fixed step while moving the measuring method of acquiring a radar image along the line direction, which is recorded an image sensing radar and radar line take the relationship calculated tAW at a fixed pitch in accordance with the optimal antenna spacing and ~X relationship tAW~X and; calculation of the dielectric constant of the soil: the parameters into the formula Tetouan

壤的介电常数 Soil permittivity

其中地波速率V、地波走时tew、空气波走时 Wherein when the wave velocity V, the wave travel tew, air traveltime

tAW、天线间距X、C为电磁波在真空中的速度0. 3m · ns-1 ;土壤含水量的计算:将计算得到的土壤介电常数ε 代入θ = -5. 3Χ 1(Γ2+2· 92Χ 1(Γ2 ε -5. 5Χ 1(Γ4 ε 2+4. 3Χ 1(Γ6 ε 3,得土壤含水量。其中,上述共中点法确定空气波和地波走时的具体步骤为:测线长选择15m至20m, 发射和接收天线的起始位置在测线中点南北各IOcm处,起始间距20cm,采集步长20cm,即两个天线每次各沿测线向外移动10cm。 tAW, antenna interval X, C is the speed of electromagnetic wave in vacuum 0. 3m · ns-1; soil water content calculated: soil calculated dielectric constant ε substituting θ = -5 3Χ 1 (Γ2 + 2 · .. 92Χ 1 (Γ2 ε -5 5Χ 1 (Γ4 ε 2 + 4 3Χ 1 (Γ6 ε 3, wherein soil moisture to give the common midpoint method to determine the specific steps of the air wave and ground wave to go: measuring line length selection 15m to 20m, the transmitting and receiving antennas at the measuring points in the line start position of the north and south IOcm, the starting pitch 20cm, 20cm long acquisition step, i.e. two per each antenna moves outwardly along the survey line 10cm.

Claims (2)

  1. 基于低频探地雷达地波法的测定砂质土壤含水量的方法,其特征在于测定步骤为:a.通过共中点法采集探地雷达数据,以确定空气波和地波走时:发射天线和接收天线按固定步长沿着测线向相反方向对称地移动,保持一个共中心点,其雷达记录为天线间距与雷达波的走时关系,获取能清晰分离出空气波和地波的不同天线间距x对应的空气波走时tAW和地波走时tGW,回归获取tAW~x和tGW~x关系式;b.以固定间距法采集土壤剖面的雷达波信息:保持探地雷达发射天线和接收天线的间距不变,按固定步长沿着测线方向同时移动的获取雷达图像的测定方法,其雷达图像记录为测线与雷达波走时关系,根据tAW~x和tGW~x关系式计算出固定间距最佳天线间距时的tAW和tGW;c.土壤介电常数的计算:将参数代入公式得土壤的介电常数其中地波速率v、地波走时tGW、空气波走 The method of measuring soil moisture content is low sandy GPR method based on the ground wave, wherein the measurement steps of: a GPR when collecting data by common midpoint method to determine the air wave and ground wave to go: transmitting antenna and the receiving antenna is moved symmetrically along a fixed step size measured in the opposite line, holding a total center point, which is recorded radar antenna spacing and down relationship radar acquires clearly different antennas separated air wave and ground wave pitch TAW and the traveltime x corresponding air traveltime tGW, regression obtain tAW ~ x and tGW ~ x relationship; B radar information collection of the soil profile at a fixed pitch method: holding GPR transmit and receive antennas spacing constant, fixed step while moving the measuring method of acquiring a radar image along the line direction, which is recorded an image sensing radar and radar line take the relationship is calculated according to a fixed pitch and tAW ~ x tGW ~ x relationship most tAW TGW and when good antenna spacing; C calculating the dielectric constant of soil: the parameter into the formula to obtain the dielectric constant of the soil in which the wave velocity v, when the waves go tGW, go airwave tAW、天线间距x、c为电磁波在真空中的速度0.3m·ns‑1;d.土壤含水量的计算:将计算得到的土壤介电常数ε代入θ=‑5.3×10‑2+2.92×10‑2ε‑5.5×10‑4ε2+4.3×10‑6ε3,得土壤含水量。 tAW, antenna spacing x, c is the speed of electromagnetic wave in vacuum 0.3m · ns-1; d is calculated soil water content: The calculated dielectric constant ε soil substituting θ = -5.3 × 10-2 + ​​2.92 × 10-2ε-5.5 × 10-4ε2 + 4.3 × 10-6ε3, to obtain soil moisture. FSA00000256878500011.tif FSA00000256878500011.tif
  2. 2.根据权利要求1所述的基于低频探地雷达地波法的测定砂质土壤含水量的方法,其特征在于共中点法确定空气波和地波走时的具体步骤为:测线长选择15m至20m,发射和接收天线的起始位置在测线中点南北各IOcm处,起始间距20cm,采集步长20cm,让两个天线每次各沿测线向外移动10cm。 The method for measuring low sandy soil GPR ground wave method based on the water content, characterized by determining the specific common midpoint method steps of the air wave and ground wave to go to the claim 1: selected survey line length 15m to 20m, the starting position of the transmitting and receiving antennas in the north and south IOcm measured at the midpoint of the line, the starting distance 20cm, 20cm long acquisition step, so that each of the two antennas along each survey line moves outwardly 10cm.
CN 201010272467 2010-09-03 2010-09-03 Method for determining sandy soil moisture content based on low-frequency ground wave radar method CN101915771B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201010272467 CN101915771B (en) 2010-09-03 2010-09-03 Method for determining sandy soil moisture content based on low-frequency ground wave radar method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 201010272467 CN101915771B (en) 2010-09-03 2010-09-03 Method for determining sandy soil moisture content based on low-frequency ground wave radar method

Publications (2)

Publication Number Publication Date
CN101915771A true true CN101915771A (en) 2010-12-15
CN101915771B CN101915771B (en) 2012-09-12

Family

ID=43323332

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 201010272467 CN101915771B (en) 2010-09-03 2010-09-03 Method for determining sandy soil moisture content based on low-frequency ground wave radar method

Country Status (1)

Country Link
CN (1) CN101915771B (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102590874A (en) * 2012-01-16 2012-07-18 中国矿业大学(北京) Method for detecting ground surface crack of upland coal-mining subsidence paddy field
CN103149220A (en) * 2013-01-30 2013-06-12 中国科学院对地观测与数字地球科学中心 Soil moisture inversion method of mono-frequency microwave radiometer
CN103741658A (en) * 2014-01-08 2014-04-23 江苏省水利科学研究院 Method for realizing joint survey of sand blowing and filling amount by adopting ground penetrating radar and static penetrometer
WO2014131515A3 (en) * 2013-02-28 2014-10-23 Daniel Seyfried Method and apparatus for determining the topography of a plant
CN104502384A (en) * 2014-12-31 2015-04-08 河南农业大学 Method and device for detecting bubbled ground based on radar
CN104535591A (en) * 2015-01-19 2015-04-22 石河子大学 Method and device for monitoring soil moisture content of farmland soil in real time based on wireless electromagnetic waves
CN104777282A (en) * 2014-01-15 2015-07-15 中国矿业大学 Multifunctional testing device for determining water content of disturbed soil with ground penetrating radar
CN105220694A (en) * 2015-10-26 2016-01-06 河海大学 Estimation method for engineering riprap amount
CN104777282B (en) * 2014-01-15 2017-04-12 中国矿业大学 The soil water content multi-function testing apparatus Penetrating Radar disturbance

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5384715A (en) * 1993-08-27 1995-01-24 The Texas A&M Univeristy System System identification and analysis of subsurface radar signals

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5384715A (en) * 1993-08-27 1995-01-24 The Texas A&M Univeristy System System identification and analysis of subsurface radar signals

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
《Vadose Zone Journal》 20031231 J.A.Huisman et.al. Measuring Soil Water Content with Ground Penetrating Radar : A Review 476-491 1-2 第2卷, 2 *
《中国生态农业学报》 20090930 朱安宁等 基于探地雷达的土壤水分测定方法研究进展 1039-1044 1-2 第17卷, 第5期 2 *
《土壤》 20110215 吉丽青 低频探地雷达地波法测定土壤含水量的可行性研究 123~129 1-2 第43卷, 第1期 2 *
《地球物理学进展》 20071031 何亮等 探地雷达测定土壤含水量的研究进展 1673-1679 1-2 第22卷, 第5期 2 *
《工程地球物理学报》 20100830 冉弥等 探地雷达测量土壤含水量综述 480-486 1-2 第7卷, 第4期 2 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102590874A (en) * 2012-01-16 2012-07-18 中国矿业大学(北京) Method for detecting ground surface crack of upland coal-mining subsidence paddy field
CN102590874B (en) 2012-01-16 2014-05-14 中国矿业大学(北京) Method for detecting ground surface crack of upland coal-mining subsidence paddy field
CN103149220A (en) * 2013-01-30 2013-06-12 中国科学院对地观测与数字地球科学中心 Soil moisture inversion method of mono-frequency microwave radiometer
CN103149220B (en) * 2013-01-30 2016-03-16 中国科学院对地观测与数字地球科学中心 A single-frequency microwave radiometer inversion soil moisture
WO2014131515A3 (en) * 2013-02-28 2014-10-23 Daniel Seyfried Method and apparatus for determining the topography of a plant
CN103741658A (en) * 2014-01-08 2014-04-23 江苏省水利科学研究院 Method for realizing joint survey of sand blowing and filling amount by adopting ground penetrating radar and static penetrometer
CN103741658B (en) * 2014-01-08 2016-02-24 江苏省水利科学研究院 GPR method and Static penetrometer combined amount of hydraulic fill sand surveying
CN104777282A (en) * 2014-01-15 2015-07-15 中国矿业大学 Multifunctional testing device for determining water content of disturbed soil with ground penetrating radar
CN104777282B (en) * 2014-01-15 2017-04-12 中国矿业大学 The soil water content multi-function testing apparatus Penetrating Radar disturbance
CN104502384A (en) * 2014-12-31 2015-04-08 河南农业大学 Method and device for detecting bubbled ground based on radar
CN104535591A (en) * 2015-01-19 2015-04-22 石河子大学 Method and device for monitoring soil moisture content of farmland soil in real time based on wireless electromagnetic waves
CN105220694A (en) * 2015-10-26 2016-01-06 河海大学 Estimation method for engineering riprap amount
CN105220694B (en) * 2015-10-26 2017-08-01 河海大学 An engineering method to estimate the amount of riprap

Also Published As

Publication number Publication date Type
CN101915771B (en) 2012-09-12 grant

Similar Documents

Publication Publication Date Title
US7034740B2 (en) Method and apparatus for identifying buried objects using ground penetrating radar
Grote et al. Field‐scale estimation of volumetric water content using ground‐penetrating radar ground wave techniques
US20060132137A1 (en) Electromagnetic surveying for hydrocarbon reservoirs
US7565245B2 (en) Electromagnetic surveying
Weihermüller et al. Mapping the spatial variation of soil water content at the field scale with different ground penetrating radar techniques
Holden et al. Application of ground‐penetrating radar to the identification of subsurface piping in blanket peat
Nakashima et al. Estimation of groundwater level by GPR in an area with multiple ambiguous reflections
Lunt et al. Soil moisture content estimation using ground-penetrating radar reflection data
Weiler et al. Comparison of ground penetrating radar and time-domain reflectometry as soil water sensors
Zenone et al. Preliminary use of ground-penetrating radar and electrical resistivity tomography to study tree roots in pine forests and poplar plantations
Hubbard et al. Quantifying and relating land-surface and subsurface variability in permafrost environments using LiDAR and surface geophysical datasets
Galagedara et al. An analysis of the ground‐penetrating radar direct ground wave method for soil water content measurement
Blonquist Jr et al. A time domain transmission sensor with TDR performance characteristics
US20110227577A1 (en) Single well reservoir imaging apparatus and methods
Stoffregen et al. Accuracy of soil water content measurements using ground penetrating radar: comparison of ground penetrating radar and lysimeter data
Lambot et al. Remote estimation of the hydraulic properties of a sand using full-waveform integrated hydrogeophysical inversion of time-lapse, off-ground GPR data
Strobbia et al. Multilayer ground-penetrating radar guided waves in shallow soil layers for estimating soil water content
Hubbard et al. Mapping the volumetric soil water content of a California vineyard using high-frequency GPR ground wave data
Topp State of the art of measuring soil water content
Lambot et al. Effect of soil roughness on the inversion of off‐ground monostatic GPR signal for noninvasive quantification of soil properties
US20100057363A1 (en) Method of and apparatus for analyzing data from an electromagnetic survey
CN101520517A (en) Method for accurately evaluating targets containing oil gas in clastic rock basin
Constable Marine electromagnetic induction studies
US7659721B2 (en) Electromagnetic surveying for hydrocarbon reservoirs
WO2007053025A1 (en) A method for hydrocarbon reservoir mapping and apparatus for use when performing the method

Legal Events

Date Code Title Description
C06 Publication
C10 Entry into substantive examination
C14 Grant of patent or utility model
EXPY Termination of patent right or utility model