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1、Chap.4 Distance surveying and line orientation,Highway school Changan university,Chap.4 Distance surveying and,Chap.4 Distance surveying and line orientation,Distance: refers to length of the curve line between two projections of two points to the geoid along the plumb line.Main contents: 钢尺量距（steel
2、 tape distance surveying）； 视距测量（stadia surveying ）；光电测距（photoelectric surveying distance）卫星测距（Satellite ranging）；直线定向（line orientation）；,1,Chap.4 Distance surveying and,Key content:坐标方位角（ coordinates azimuth calculation ）Classification: Direct measurement method - steel tape distance surveying;Optic
3、al measurement method - stadia distance surveying； Physical measurement method - photoelectric surveying distance;,Key content:坐标方位角（ coordinates,4-1 Steel tape distance surveying,一、The tools 钢尺（Steel tape）, 标杆（benchmarking）, 测钎（measuring brazing） and 垂球（Metal ball ball）. 1. Steel tape Feet long ： 2
4、0 meters, 30 meters, 50 meters； Specifications: plastic coated or not plastic coated. Scale and note: mm, cm, dm,m 刻线尺（compartmentalized rule） 端点尺（endpoint rule）,Endpoint rule Compartmentalized rule,1,4-1 Steel tape distance surve,4-1 Steel tape distance surveying,一、The tools2. Flower stem: Fixed li
5、ne forward direction line 3. Measuring brazing: fix rule segment endpoint position. 二、直线定线（Fixing line）目测定线和经纬仪定线,1,4-1 Steel tape distance surve,4-1 Steel tape distance surveying,三、 Steel tape distance surveyingThe basic requirements: “straight, level, accurate. 1. The distance surveying at flat gr
6、ound Use the equation: D=nl+q l - the the length of whole feet; n - the whole rule section number, q - zero rule section length. surveying error: D = D往-D返Distance average: D平= （D往-D返）The relative error:,1,4-1 Steel tape distance surve,4-1 Steel tape distance surveying,2. The distance surveying at t
7、he tilt ground(1) flat surveying method: (2) inclined surveying method,1,4-1 Steel tape distance surve,4-2 Stadia surveying,Stadia surveying is indirect ranging method 它利用望远镜内十字丝分划板上的视距丝及刻有厘米分划的视距标尺(地形塔尺或普通水准尺)，根据光学原理可以同时测定两点间的水平距离和高差. The relative error is about 1/300, below the rule surveying dist
8、ance, Determine the elevation precision is below level survey, Stadia measurement is widely used for measuring the details topography Measurement.,1,4-2 Stadia surveying Stadia,4-2 Stadia surveying,一、Stadia formula when sight is horizontal,n,1,4-2 Stadia surveying 一、Stadi,4-2 Stadia surveying,一、Stad
9、ia formula when sight is horizontalHorizontal distance formula: Height difference formula:,n,l,1,4-2 Stadia surveying 一、Stadi,4-2 Stadia surveying,二、The stadia formula when sight is tiltingHorizontal distance D :Elementary height difference:The height difference between A and B:,1,4-2 Stadia surveyi
10、ng二、The st,4-2 Stadia surveying,三、 The steps of the stadia surveying1在测站上安置经纬仪，量取仪器高（桩顶至仪器横轴中心的距离），精确到cm；2瞄准竖直于测点上的标尺，并读取中丝读数值；3用上、下视距丝在标尺上读数，将两数相减得视距间隔；4使竖盘水准管气泡居中，读取竖盘读数，求出竖直角;5.根据视距公式，计算水平距离和高差及立尺点的高程。,1,4-2 Stadia surveying三、 The s,4-2 Stadia surveying,四、Stadia measurement errors1. The stadia ru
11、le partition error 2. Constant K value error 3. Vertical Angle measurement errors 4. Stadia cross reading error 5. Influence of stadia rule tilting to stadia measurement 6. The influence of external meteorological conditions to stadia measurement (1) the influence of atmospheric refraction (2) the i
12、nfluence of atmospheric turbulence,1,4-2 Stadia surveying四、Stadia,4-3 Electromagnetic rangefinder,一、Ectromagnetic ranging overview 1. Principle To record the electromagnetic wave traveling time between two endpoints round-trip once time, using its propagation velocity in the atmosphere to calculate
13、the distance between two points.,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,一、Ectromagnetic ranging overview 2. Rangefinder classification （1）carrier wave adapted Microwave rangefinder Photoelectric rangefinder 1.Laser rangefinder 2.Infrared rangefinder （2） method to calculate t
14、ime Phase type rangefinder Pulsed rangefinder,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,(3) according to distance Remote range: tens of kilometers Medium-range : from several kilometers to 10 kilometers Short-range: below three kilometers(4) by carrier number Single carrier: vi
15、sible light, Infrared light, microwave. Double carrier: visible + visible light, Visible + infrared radiation Three carrier: visible + visible + microwave, Visible + infrared + microwave etc.,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,(5) By the reflection target Diffuse target
16、(no cooperation target) Cooperation goal-flat mirror, prism Active reflector-same frequency carrier wave transponder； different frequency carrier transponder, etc,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,二、Pulse photoelectric surveying distance,1,4-3 Electromagnetic rangefind,
17、4-3 Electromagnetic rangefinder,三、Phase photoelectric rangefinder 1.Basic principle,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,三、Phase photoelectric rangefinder 2Basic formula Modulation wave modulation frequency f, angular frequency t, period T,1,4-3 Electromagnetic rangefind,4
18、-3 Electromagnetic rangefinder,三、Phase photoelectric rangefinder 2Basic formula Set modulated signal is sine signal, including the euploid of 2,2 N2, and terminal part less than 2, namely:,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,三、Phase photoelectric rangefinder3The determina
19、tion of N value,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,三、Phase photoelectric rangefinder4The inner light path set,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,四、Total reflecting prisms 由于光在玻璃中的折射率为1.51.6，而光在空气中的折射率近似等于1，也就是说光在玻璃中的传播要比空气中慢，因此光在棱镜中传播所用的超量时间会
20、使所测距离增大某一数值，称为棱镜常数。,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,五、Distance measurement steps 测距时，将测距仪和反射镜分别安置在测线的两端，仔细地对中。接通测距仪的电源，然后照准反射镜，检查经反射镜反射回的光强信号。合乎要求后即可开始测距。六、Distance measurement data process1Add constants correct,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rang
21、efinder,六、Distance measurement data process2Multiply constant corrections 3Meteorological correct 不同型号的测距仪，气象改正公式的系数也不同，在仪器使用说明书内给出了气象改正计算公式。4.Tilt correction 5To calculate to geoid corrections,1,4-3 Electromagnetic rangefind,4-3 Electromagnetic rangefinder,七、Error sources of photoelectric rangingDi
22、stance error can be divided into two parts: The first part error of it is proportional to distance D, namely the speed of light value error, atmospheric refraction error and ranging frequency error; Another part is irrelevant with distance, namely phase error, to add constant error, plummet error, G
23、enerally rangefinder precision expression,1,4-3 Electromagnetic rangefind,1,4-4 Electromagnetic wave rangefinder inspection,一、OverviewInspection items mainly include: 1 function examines, 2 The correctness of calibration of three axis relationship 3 luminescence tubes phase uniformity (beadle error)
24、 measurement, 4 Amplitude phase error measurement, 5 period errors measurement, 6 determination of add constants 7 by constant (including crystal frequency), 8 internal and external precision of the examination. 9 adaptive performance testing:10 measurement process detection,14-4 Electromagnetic wav
25、e ran,4-4 Electromagnetic wave rangefinder inspection,一、OverviewInspection items mainly include: 功能检视;三轴关系正确性的检校;发光管相位均匀性（照准误差）的测定；幅相误差的测定；周期误差的测定；加常数的测定；乘常数（包括晶振频率）的测定；内部、外部符合精度的检验；适应性能的检测：测程的检测。,1,4-4 Electromagnetic wave rang,4-4 Electromagnetic wave rangefinder inspection,二、The determination of
26、the period errors1. What is the period errors Cycle repeated error according to certain distance, mainly comes from internal fixed crosstalk signal.,1,4-4 Electromagnetic wave rang,4-4 Electromagnetic wave rangefinder inspection,二、The determination of the period errors 2The measurement method of the
27、 period errors,1,4-4 Electromagnetic wave rang,4-4 Electromagnetic wave rangefinder inspection,三、The determination of surveying distance constant1. Simple measurement of add constant2.Fix add, by constant by 6 sections comparison. To get the observation value by comparison method ,to compare observa
28、tion with the known baseline data to obtain constant K, by constant R.,1,4-4 Electromagnetic wave rang,4-5 Line orientation,Determine the horizontal angle between a straight line and a basic direction. 一、Basic direction1True north direction :过地面某点真子午线的切线北端所指示的方向。采用天文测量的方法测定。2Magnetic north direction
29、 ：磁针自由静止时其指北端所指的方向，称为磁北方向，可用罗盘仪测定。 3Coordinates north direction ：过O点的真子午线坐标纵轴（X轴）正向所指示的方向，称为坐标北方向。实用上常取与高斯平面直角坐标系中X坐标轴平行的方向为坐标北方向。,1,4-5 Line orientationDetermine,4-5 Line orientation,二、方位角（Azimuth ） An azimuth is the direction of a line as given by an angle measured clockwise from the north end of
30、a meridian. It ranges in magnitude from 0360。1True azimuth (A): the direction of a line as given by an angle measured clockwise from the true north。2. Magnetic azimuth(Am)：the direction of a line as given by an angle measured clockwise from the magnetic north。3Grid azimuth()：the direction of a line
31、as given by an angle measured clockwise from the Grid north。,1,4-5 Line orientation二、方位角（Azi,4-5 Line orientation,三、磁偏角（Magnetic declination） 子午线收敛角（meridian convergence）1Magnetic declination: The horizontal angle between the north of the compass and true north 。2meridian convergence： The horizontal
32、 angle between true and grid north。 and are positive when themagnetic north or grid north is in the east to true north, the otherwise are negative.,过O点的真子午线,1,4-5 Line orientation三、磁偏角（Mag,4-5 Line orientation,四、The relationship between three azimuths,1,4-5 Line orientation四、The rel,4-5 Line orienta
33、tion,五、Pros and cons grid azimuth,1,4-5 Line orientation五、Pros an,4-6 The azimuth surveying,一、Compass determination magnetic azimuth 1. compass construction telescope, compass box, base,1,4-6 The azimuth surveying一、Co,4-6 The azimuth surveying,一、A compass determination magnetic azimuth 2.Compass ope
34、ration（1）安置罗盘仪于直线的一个端点，进行对中和整平。 （2）用望远镜瞄准直线另一端点的标杆。（3）松开磁针制动螺旋，将磁针放下，待磁针静止后，磁针在刻度盘上所指的读数即为该直线的磁方位角。,1,4-6 The azimuth surveying一、A,4-6 The azimuth surveying,二、Gyro theodolite determination true azimuth1Gyro theodolite construction由望远镜、罗盘盒、基座三部分组成。,GYROMAT2000,AGP1,1,4-6 The azimuth surveying二、Gy,4-6
35、 The azimuth surveying,二、Gyro theodolite determination true azimuth1Gyro theodolite observation methods(1) Roughly orientation 两逆转点法: 四分之一周期法：,1,4-6 The azimuth surveying二、Gy,4-6 The azimuth surveying,（2）Precision direction 精密定向一般采用跟踪逆转点法和中天法。,1,4-6 The azimuth surveying（2）P,Chapt.4 Content review,1. Steel tape distance surveying2. Stadia measurement3. Electromagnetic rangefinder 4. Electromagnetic rangefinder inspection 5. Line orientation6. The azimuth surveying,Thats all for this chapter！,1,Chapt.4 Content review1. Ste,
