This specification is applicable to medium and short-range photoelectric ranging work such as second, third and fourth-class geodetic surveying, urban surveying, engineering surveying (including construction surveying), various levels and non-level plane control networks, and terrain control surveying, and does not involve the layout of the control network. Other precision electrical ranging can be implemented as a reference. GB/T 16818-1997 Medium and Short-Range Photoelectric Ranging Specification GB/T16818-1997 Standard Download Decompression Password: www.bzxz.net
This specification is applicable to medium and short-range photoelectric ranging work such as second, third and fourth-class geodetic surveying, urban surveying, engineering surveying (including construction surveying), various levels and non-level plane control networks, and terrain control surveying, and does not involve the layout of the control network. Other precision electrical ranging can be implemented as a reference.

GB/T 16818-1997
This standard is drafted and formulated on the basis of the original ZBA7600287 "Medium and Short Range Photoelectric Distance Measurement Specification", according to the development level of medium and short range photoelectric distance measurement in China, and with reference to the relevant standards of some foreign countries. This specification does not involve instrument detection and measurement point burial. For relevant detection technology and measurement standards, please refer to the "reference standard" clause. Appendices A, B, C, D, E and F of this standard are all informative appendices. This standard is proposed and managed by the State Administration of Surveying, Mapping and Geoinformation. The drafting unit of this standard is the Surveying and Mapping Standardization Institute of the State Administration of Surveying, Mapping and Geoinformation. The main drafters of this standard are Peng Yuhui and Ren Daosheng. 202
1 Scope
National Standard of the People's Republic of China
Specifications for short to medium rangeselectro-optical distance measurementsGB/T 16818-997
This specification is applicable to medium and short range photoelectric distance measurement work such as second, third and fourth class geodetic surveying, urban surveying, engineering surveying (including construction surveying) and various levels and sub-level plane control networks and terrain control surveying, and does not involve the layout of control networks. Other precision photoelectric distance measurement can be implemented by reference.
2 Reference Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest version of the following standards. JJG703-90 Photoelectric distance meter
CH8001-90 Photoelectric distance meter calibration specification
3 Symbols
D'—Observation distance·m;
D--Measured slant distance after various corrections, m; D--Linear chord length, m;
D,-Horizontal distance or chord length on the reference ellipsoid, m; Dz-Horizontal distance or arc length on the reference ellipsoid, m; k--Refractive coefficient α0.13);
r-Earth radius, m, r is often replaced by the average earth radius m: H1, H.-Measurement point reference ellipsoid elevation, m; Ellipsoid elevation is replaced by normal elevation. 4 Basic requirements
Medium and short-range photoelectric distance measurement refers to the distance measurement using a photoelectric distance meter (referred to as a distance meter) with a range of less than 15km. Photoelectric distance meters are classified into medium, short and long range according to the range. The range of the rangefinder is within 3km, the range of the rangefinder is between 3km and 15km, the rangefinder is medium-range, and the rangefinder is greater than 15km. The rangefinder is classified into four levels of accuracy based on the absolute value of the nominal accuracy of the rangefinder at the factory and the standard deviation of the rangefinder calculated to 1km (see Table 1). Approved by the State Bureau of Technical Supervision on May 28, 1997, and implemented on February 1, 1998
Accuracy grade
N (extra-standard grade)
GB/T 16818-
Accuracy classification of distance meters
Standard deviation of distance measurement
ml≤.2 mm
2 mm≤/mmls5 mm
5 mmImulsi0 mm
10 mm [m}
The expression (1) for the factory nominal accuracy of the distance meter is: (A-tBXD)
Where: A—nominal accuracy weekly error, mm; B—nominal accuracy proportional error coefficient.mm/km; 5 Conditions and preparation for distance measurement
5.1 According to the accuracy requirements of the distance measurement grade, a distance meter with the same or higher grade accuracy should be used. 5.2 Inspection and requirements of the instrument
5.2.1 Inspection of distance meter. According to JJG703-90. Instruments used for measuring the starting side greater than 1km should be checked by comparing multiple sections on the baseline above 1km to meet the corresponding starting side accuracy requirements. 5.2.2 Other measuring instruments used in conjunction with distance measurement, such as theodolite, ten-wet thermometer, barometer, steel tape measure, etc., should be calibrated according to their corresponding calibration procedures. Have complete calibration data. The technical requirements of dry, wet thermometers and barometers used by distance meters of different grades are shown in Table 2. Table 2 Technical requirements for meteorological instruments
Minimum number
Meteorological instruments
Dry and wet thermometers
Distance meter accuracy level
The centering device used in conjunction with the distance meter has the centering accuracy requirements shown in Table 3. Table 3 Requirements for centering device accuracy
Distance meter accuracy level
Jiang, N
5.3 Requirements for points and measuring lines
Requirements for centering accuracy
Forced centering device or precision optical centering device
Optical centering device
Centering rod or hammer ball
5.3.1 The points used for distance measurement should have obvious centering marks or forced centering device interfaces, and the points should be stable, firm and easy to preserve. For permanent marks, ground markers or observation piers should be buried on the bedrock or under the ice and soil. For the stability of temporary points, it is required that the changes affected by external factors should be better than one-fifth of the required distance measurement accuracy during its service life. 5.3.2 When designing the starting edge, conductor edge or other distance measurement edge length of the plane control network, the best use conditions and the maximum measurement range of the distance meter used should be taken into account.
GB/T16818-1997
5.3.3 The survey line should be at least 1.3m above the ground or obstacles, and the height of the instrument arm should be determined according to the landform and ground conditions of the survey line. 5.3.4 There should be no permanent reflective objects on the survey line or its extension line. The survey line should avoid being parallel to the high-voltage (35kV or above) transmission line. If it cannot be avoided, it should be at least 2m away from the transmission line. 5.3.5 The survey line should avoid passing through areas with large differences in heat absorption and heat dissipation. Such as towns, lakes, river valleys, etc. If it cannot be avoided, the survey line should be raised to more than 2m, and a favorable observation time should be selected so that the meteorological data measured at the two end points are better representative of the entire survey line.
5.3.6 There should be no alternating electromagnetic field influence around the arranged measuring points, especially the high-frequency electromagnetic field influence. 5.3.7 The permanent point markers and observation piers shall be buried in accordance with the relevant provisions of the triangulation and traverse measurement specifications and the relative long baseline measurement specifications in combination with the centering method of the distance meter used. 5.3.8 The height difference between the two ends of the distance measurement should not be too large and should meet the following requirements: a. If the height difference between the two ends of the distance measurement is measured by the opposite trigonometric height method, the limit of the height difference shall be calculated according to formula (2): h8D
where: h—height difference between the two ends of the distance measurement, m;
---the value of the denominator of the relative mean error required for the distance measurement. b. If the height difference between the two ends of the distance measurement is measured by grade leveling, except for considering the maximum pitch angle of the distance meter used, the size of the height difference is not limited.
5.4 Data preparation before distance measurement
5.4.1 Collect the topographic map, point selection map and relevant traffic, meteorological and other data of the survey area according to the design task book. 5.4.2 Collect complete calibration data of distance meters and meteorological instruments, maintenance and troubleshooting records, etc. 6 Distance measurement
6.1 Selection of observation time
6.1.1 The selection of observation time should be based on the requirements of distance measurement accuracy and the accuracy level of the distance meter used, the terrain and objects at the measuring point, the season, weather conditions, atmospheric transparency and other factors. 6.1.2 Distance measurement of each level should be carried out within the best observation time period, that is, within one hour before and after the time when the vertical gradient of air temperature is zero. Generally, observations are made within the time period of 0.5h to 2.5h after sunrise and 2.5h to 0.5h before sunset in the measuring area. When the accuracy of the Sichuan distance meter is better than the required distance measurement accuracy, the observation time period can be appropriately extended towards the mid-sky direction. However, on sunny days or with few clouds, measurements should not be made within 1h before and after noon and midnight. 6.1.3 For precision distance measurement, in addition to strictly measuring distance in the best time period, symmetrical observations should be made in the morning and afternoon. The round trip measurement of each level of edge can be carried out in the morning and afternoon or in different time periods during the day. 6.1.4 When it is completely cloudy and there is a light breeze, observation can be carried out all day, and try to avoid the time within 1 hour before and after noon and midnight. 6.1.5 There is no need to strictly limit the observation time for the distance measurement of the length of each level of control edge outside the level. 6.1.6 Distance measurement should not be carried out before and after thunderstorms, heavy fog, strong wind (level 4 or above), rain, snow and when visibility is very poor. 6.2 Distance measurement
6.2.1 Check whether the point is stable, correctly install the instrument, and measure the height of the distance meter. Ensure sufficient instrument preheating time, especially the distance meter with a constant temperature device can only work after reaching a constant temperature. 6.2.2 Install the reflector. When installing, it should be accurately centered, leveled and aligned with the measuring station. According to the instructions of the instrument station, read and report the meteorological elements and mirror height in time.
6.2.3 Measure the height of the distance meter and reflector twice, read to millimeters, and take the average value of each. 6.2.4. Strictly follow the instrument operation procedures, input all the data that should be input, and operate the keys gently to prevent the correct placement from being damaged.
6.2.5 Matters needing attention in distance measurement:
GB/T16818—1997
Ensure good air circulation around the instrument, and avoid placing the instrument in an environment with large representative errors (such as buildings, tents, etc.). When working on sunny days, umbrellas should be used to shade the distance meter and meteorological instrument. b. It is strictly forbidden to operate the distance meter or reflector facing the sun. c. When the instrument is measuring distance, wireless calls should be suspended to avoid interference. When the instrument is measuring distance, avoid other reflectors on the measuring line or the extended line of the measuring line, avoid objects shaking on the measuring line, or people walking on the measuring line.
After the instrument is placed, the instrument station and the reflector station must not be left unattended, and attention should be paid to the working status of the instrument and changes in the surrounding environment at all times. When the wind is strong, the instrument and reflector should be protected. 6.3 Determination of meteorological elements
6.3.1 Meteorological elements include: air temperature, air pressure and absolute humidity (water vapor pressure); absolute humidity is obtained by measuring the dry and wet temperatures of the air.
6.3.2 The dry and wet temperature gauges should be placed securely in a well-ventilated windward place that is higher than the rangefinder and reflector to prevent the influence of sunlight and other heat radiation. Add distilled water to the wet bulb in an appropriate amount and ventilate for 2 minutes before reading. When reading, face the windward, keep the handrail away from the temperature sensor head, hold your breath, and quickly obtain the ten and wet temperatures with your eyes level. When the wind force is greater than level three, add a windshield. The barometer should be placed securely and flatly in a shaded place near the instrument. Note: The temperature and air pressure readings should be the instrument indication value plus the correction value. 6.3.3 The meteorological element collection mode shall be determined according to the accuracy of the distance meter, the terrain and topography, the time used for measuring the edge, and the meteorological state. a. When using a first-level instrument to measure a distance with a relative accuracy better than one in five hundred thousand, the atmospheric temperature, humidity and air pressure values ​​shall be measured at the beginning and end points of each edge (and the middle point if necessary) and the average value shall be calculated as the meteorological representative value of the measuring line; b. For the second to fourth level starting edges and guide lines, the atmospheric temperature and air pressure values ​​shall be measured at both ends of the measuring line at the same time and the average value shall be calculated. When the distance measurement time exceeds 2 minutes each time, the atmospheric temperature and air pressure values ​​shall be measured once at the beginning and end of the observation time and the average value shall be calculated. If the area is relatively flat within 500m, the surface coverage is relatively uniform, and there is wind, the air temperature and air pressure values ​​can be measured at a single end (measuring station); c. For the control edges of the second and fourth level, the atmospheric temperature and air pressure values ​​are generally measured once for each edge, and the measuring station measures the atmospheric temperature and air pressure values ​​at a single end. However, when the terrain and objects are complex, the height difference is large, and the distance is greater than 1km, the atmospheric temperature and air pressure values ​​should also be measured at both ends and the average value shall be calculated, d. For rangefinders with working frequency in the microwave band, atmospheric humidity should be measured during distance measurement. e.
For rangefinders that input meteorological element values ​​for self-correction, the average value of the meteorological elements collected above should be input into the instrument before distance measurement. However, when the meteorological element value changes (dry and wet temperature is greater than 1C, air pressure is greater than 2hPa), the new value should be input immediately and the distance should be measured again. 6.4 Technical requirements for distance measurement
6.4.1 The main accessories of the rangefinder used for distance measurement, such as reflectors, brackets, and bases, should be consistent with those used for calibration. Generally, they shall not be replaced. For off-grade distance measurement, the main accessories can be replaced, but the constant error should be within the allowable range of measurement accuracy. 6.4.2 The technical requirements for distance measurement are shown in Table 4. Table 4
Technical requirements for distance measurement
Use rangefinder accuracy level
1, 1, E
Number of measurements on each side
Or use different time periods instead of round trip measurement
GB/T16818--1997
（ ）A measurement round refers to setting up the instrument to push the target...- times and reading data five times②Time period refers to the time period for completing a distance measurement and forward or return measurement, such as morning, afternoon or different daytimes. 6.4.3 The poor limit of observation results of rangefinders of various levels of accuracy are shown in Table 5: Table 5 Poor limit of accuracy of various levels
Distance meter accuracy level
·Poor limit between readings of measurement rounds
Poor limit between measurement rounds
(①) For round-trip measurement poor, the slant distance should be converted to the same horizontal plane before comparison ②(4+B×DX10-6) is the nominal accuracy of the rangefinder, mm
Poor limit of round-trip measurement or time period
2(A+BXDX10\6)
6.4.4 Use triangulation to determine the elevation difference and make tilt correction. When observing in opposite directions, the difference in elevation should meet the requirements of formula (3): Ah ≤ 0. 1D* × 10-3
In the formula: h-——the difference of the height difference between the round trip observation, m; the requirement for the mean error of vertical angle measurement is calculated according to formula (4): mg
In the formula: o-—206265\;
-the mean error of vertical angle measurement;
Instrument-vertical angle:
-the denominator value of the relative mean error required for distance measurement. The mean error of vertical angle measurement calculated by the above formula is the argument, and the instrument, observation method and number of measurement rounds used should comply with the provisions of Table 6. Table 6 Instrument, observation method and number of rounds of measurement Angular mean error
Instrument model
Observation method
Middle wire method
Three wire method
6.5 Requirements for eccentric observation
5″～10″
10\~30″
More than 30″
6.5.1 When measuring distance, eccentric observation is generally not performed. If eccentric observation is necessary, the centroid element must be measured. The maximum eccentric distance shall not exceed 5m.
6.5.2 When observing on the mark, the left and right sides of the theodolite are used to project and measure the centroid element of the instrument. The intersection angle of the three projection planes is about 60° or 120°. If it is restricted by the terrain, it is also possible to project twice continuously at two positions with an intersection angle of about 90° (the position of the instrument should be slightly changed between the two times). 6.5.3 On the projection paper, except for the center of the benchmark stone, two observation directions should be drawn for each other projection center, one of which should preferably be the observation zero direction. The angle difference between the drawn direction and the observation direction should be less than 2°. 6.5.4 After the distance measurement, the centering element should be measured once, the angle element should be measured to 15', the length element should be measured to millimeters, and the side length of the projection error triangle should not exceed 5mm.
6.5.5 When making large eccentric observations on the ground, the eccentricity should be measured twice with a calibrated steel ruler, measured to millimeters, and the middle value can be taken. The eccentricity angle should be measured twice, and the difference should be less than or equal to 10\. 207
6.6 Requirements for results recording
6.6.1 Requirements for using hand-written notebooks
GB/T 16818--1997
6.6.1.1 Original observation data and record items must be recorded on-site in the measurement notebook. It is strictly forbidden to tear up any page in the notebook. 6.6.1.2 Numbers and words recorded on-site should be written accurately and clearly. Mistakes should be crossed out neatly, and correct numbers and words should be recorded on the top. It is strictly forbidden to erase them. The reasons and the page number of the re-measured results should be indicated for results that are crossed out due to over-limit or other reasons. The written words, symbols and measurement units should comply with the relevant standards promulgated by the state. 6.6.1.3 In on-site distance measurement, each measurement should be recorded in full, and the values ​​of centimeters and below centimeters shall not be changed. Meter and decimeter readings can only be changed in round-trip measurements of the same distance. 6.6.2 Requirements for the use of electronic bookkeeping methods
6.6.2.1 The elements, items, tolerances, etc. of the electronic bookkeeping method shall comply with the technical requirements for distance measurement. 6.6.2.2 The data processing procedures and input (printing) formats shall be reviewed, filed, and approved by the relevant technical management departments before use. 6.6.2.3 The data output (printing) format for each distance measurement shall include: time, network point name (place name), round-trip measurement number, instrument model and number, height difference, original distance reading, meteorological element reading value, final slope distance and horizontal distance, etc. 6.6.3 For instruments with large-capacity data storage, processing and communication functions, in addition to careful operation, various data input on site shall be recorded in detail, including time, network point name, mark serial number, network point mark status, etc. The stored measurement data shall be recorded in the measurement area on the same day to prevent data loss and facilitate recovery.
6.7 Remeasurement and selection of observation results
6.7.1 All observation results that exceed the tolerances listed in Table 5 should be remeasured. 6.7.2 When the difference in readings in a measurement round exceeds the limit, two readings can be remeasured, and then the large and small isolated values ​​can be removed and the average is taken. When the remeasurement exceeds the limit, the entire measurement should be re-observed. If it exceeds the limit repeatedly, the cause should be analyzed and the measurement should be repeated on another day. 6.7.3 When the difference between measurement rounds exceeds the limit, if they are grouped in pairs, the period should be remeasured; if there is only one isolated value, remeasure one measurement round. The remeasurement cannot exceed half. Otherwise, remeasure all the measurement rounds in the entire period. 6.7.4 When the distance in the outbound and return directions (or in different time periods) exceeds the limit, the cause should be analyzed and the distance in one direction should be remeasured. If the distance still exceeds the limit after remeasurement, the distance in both directions should be remeasured.
7 Distance calculation
7.1 Calculation of various distance correction values
7.1.1 Calculation of meteorological correction value:
ADn. D'(n.- n) × 106
Where: AD.
Meteorological correction value, mm;
Group refractive index of the instrument meteorological reference point,
Actual group refractive index under meteorological conditions during measurement Where (n.1)(287.604+3×16288+5×0.0136)×10\273.16P
(n; — 1) = (ng —1)
(273.16+1) X 1 013. 25
Wherein:
wavelength of the distance measuring light source in vacuum, um;
group refractive index of light under standard atmospheric conditions; air temperature,;
P-air pressure, hPa,
~water vapor pressure, hPa;
wherein: e=Ec(tt)P
E-10fat/(b+]+0.7H5 H
Wherein: dry bulb temperature, ℃
11. 27 X 10-6
273. 16 + t
（6）
.（7）
（8）
\——wet bulb temperature, C;
air pressure, hPa
E——saturated water vapor pressure, hPa;
α, h, coefficient. The values ​​are shown in Table 7.
GB/T 16818-- 1997
Table 7 Coefficient values
Wet bulb not frozen
0.000 662
Wet bulb frozen
According to different distance measurement accuracy requirements, the meteorological correction formula given in the instrument manual and the corresponding meteorological elements can be used or directly input into the instrument or calculated separately.
7.1.2 Calculation of refractive index correction:
ADn—（kA
Where: △Dn2 ---
- refraction correction value, m;
Note: This correction is made for distances above 10km. 7.1.3 Calculation of precision frequency change distance correction value AD,=
Where: △D;--frequency change distance correction value, m; Wan--average value of displayed slant distance, m;
fa——nominal precision frequency of rangefinder, Hz, f--actual precision frequency of rangefinder, Hz.
Note: "The precision frequency value is given in the calibration certificate. 7.1.4 Calculation of period error correction value:
ADA = Asin[ +
Where: ADA-periodic error correction value, mm; A-amplitude of period error, mm;
do\-initial phase angle of period error, \);-precision modulation wavelength of rangefinder, m.
X 3601
(10 ）
（11）
·（12）
Note: The amplitude A of the periodic error and the initial phase angle are given in the calibration certificate. If the amplitude A of the periodic error is greater than √2 times the absolute value of the error in the distance measurement, this correction should be made.
This correction is not made for pulse distance meters. 7.1.5 Calculation of the additive and multiplicative constant correction values ​​of the distance meter: Additive constant correction value: ADk=K
Multiplicative constant correction value.△DkR·D\.
Where: K-
-additive constant of the distance meter, mm;
R-multiplicative constant of the distance meter, mm/km
（13）
·（14 )
Note: The additive and multiplicative constants of the distance meter are calculated by measuring multiple known distances and correcting for frequency, meteorological and periodic errors. Its value is given in the calibration certificate.
In the calibration of the rangefinder, if the distance is corrected for frequency, and the multi-segment reduction result is the multiplication constant R1>1×10-6, you should first check whether the meteorological element sampling is correct, whether the frequency measurement and formula application are incorrect, and if the above are normal, you should perform a comparison on different baseline segments or different baseline fields. When the test results are consistent with the above results, the measured multiplication constant is valid. The frequency and multiplication constant corrections are performed in time. If the distance is corrected for frequency, the result is multiplied by the constant 1R「1×10-6, then only the frequency or multiplication constant single correction is performed. 7.1.6 The slope distance can be converted to the horizontal (or reference ellipsoid) distance after being corrected for meteorological, frequency, periodic errors, additive constants, and multiplication constants.
7.2 Geometric correction of measured distance
7.2.1 Calculation of the centering correction value for eccentric station measurement: a) When the eccentric distance W≤0.3m, calculate according to the following formula: ADw =- W. cos - W'. cose'
Where: W-eccentricity of the measuring station;
Eccentricity angle of the measuring station, i.e. the angle between the eccentricity of the measuring station and the direction of observation; 9-
Eccentricity of the mirror station;
Eccentricity angle of the mirror station, i.e. the angle between the eccentricity of the mirror station and the direction of observation. b) When the offset W>0.3m is used for large eccentric observation, the formula for calculating the horizontal distance is: D. = VD + W2 - 2DwWcoso
Where: W-eccentricity of the measuring station, m;
Eccentricity angle of the measuring station;
Dw——Horizontal distance of eccentric observation.
7.2.2 After various corrections, the formula for converting the measured distance D into horizontal distance or onto the reference ellipsoid is as follows: a) For short distances within 3km, the formula for calculating the horizontal distance is: D, D? AH2
b) For the measured distance D of more than 3km, first convert it to the chord length D of the straight line between the two end points, and the formula is D.=D-k2
（15 ）Www.bzxZ.net
（16）
For medium and short distances (D<15km), this item can be ignored, D. ~D; then convert the chord length D of the straight line between the two points to the chord length D of the reference ellipsoid, and the formula is:
D -(H, H,)2
D,=Na+HR(+HD
Convert the chord length on the reference ellipsoid to the arc length on the reference ellipsoid, and the formula is: Dz= Di +
·（19）
（20）
In the above formulas, the ellipsoid elevation is replaced by the normal elevation; the normal elevation can be obtained from leveling or trigonometric elevation. The ellipsoid elevation is only used in high-level geodetic measurements, while the difference between the ellipsoid elevation and the normal elevation can be ignored in low-level or short-range measurements.
7.2.3 Use the measured zenith distance to convert the distance to the reference ellipsoid surfacea) First convert the measured distance to the chord length of the straight line. For medium and short distances (<15km), this correction can be ignored, and the measured distance is approximately equal to the chord length of the straight line.
b) Perform tilt correction on the chord length of the straight line (i.e., the slant distance) and convert it to a horizontal distance. The formula is: Dht = DesinZ, -
c) Convert D to the chord length on the reference ellipsoid: D%(2 - k)
sin2Z,
D, D(1 - H,/r)
d）The formula for converting the chord length of a straight line on the reference ellipsoid into arc length is: Dz = D, + Di/24r2
（21）
（22）
(23）
In the above formulas:
GB/T 16818—1997
horizontal distance from measuring point P, to point P, m;
Z,-—zenith distance at measuring point P, (°); H,-normal height of measuring point P, m.
7.2.4 Calculate the height difference using the observed zenith distance and slant distance: a) One-way observation
b) Opposite observation
In the above two formulas
(1=k)(Desinz)2
H, -- H1 -- Dcosz+ +
H, -- H, D,/2(cosZ? -- cosZ21)Z12——Zenith distance from P, to P, measuring point, (°): Z2——Zenith distance from P to P measuring point, (°). 7.2.5 The length D on the reference ellipsoid is converted to the length D on the Gaussian plane. Calculate according to the following formula: + (A
D.= D,[1 +
The difference in horizontal coordinates between the two end points of the survey line, Ay=yi-yi; where: Ay—
-The average value of the horizontal coordinates of the two end points of the survey line, ym-1/2(y+y), m; -The average earth radius of the midpoint of the survey line on the reference ellipsoid, m. 7.2.6 The length of the horizontal distance to any other elevation surface is calculated according to the following formula: D, - D,(1 - H'm/ra)
Where D
The distance on any elevation surface, m,
-The average elevation of the two end points of the horizontal distance to any elevation surface, m; Hm'-The radius of curvature of the
normal section, m.
Where: rA— VNM(1-
e'?cos*βmcos2a)
Where: M, N—respectively are the meridian and meridian curvature radii of the midpoint of the ranging edge, m; the eccentricity of the ellipsoid used;
βm—the latitude of the midpoint of the ranging edge, \;
—the azimuth of the ranging edge, . .
7.3 Accuracy assessment of distance measurement
7.3.1 Accuracy assessment of one-way observation distance
According to the accuracy of the ranging instrument, the placement, use and environmental conditions during ranging, the ranging accuracy is estimated by analyzing the size of the ranging error source. The error formula for ranging adopts the empirical formula: mo=±(A+B XD)
wherein: A--fixed error, mm;
B---proportional error coefficient, mm/km;
wherein: A[m+m2+m+m+m]1/2
B--Em+m+m+m]1/?
-additive constant measurement error, given in the calibration certificate; where: mi-
m2--phase uniformity error, given in the calibration certificate; ms--periodic error measurement error, given by the calibration department; m--centering error, determined by the centering method used, refer to Table 3;·(24)
-(25)
(26)
(27)
GB/T 16818—1997
——mean error of the arithmetic mean of the observation results at each distance, calculated by the following formula: [Vv]
Nn(n - 1)
the difference between each reading and the mean of the readings;
number of readings;
m——mean error of determination by multiplication constant, given by the calibration department; m
error of the refractive index calculation formula, generally taken as 0.2×10-; m—drift of the precision measurement frequency and relative mean error of determination; ·(29)
m.-representative meteorological error, related to the atmospheric conditions and the terrain and surface cover through which the survey line passes, and the empirical value is shown in Table 8. Table 8 Empirical value table of representative meteorological errors
Representative meteorological conditions
7.3.2 Accuracy assessment of opposite observation distance
a) The mean error of the "second measurement is calculated using the following formula: Meteorological measurement at one end
b) The mean error of the average value of opposite observations is calculated using the following formula: ma =
c) Relative mean error:
= D,/md
In the above formula: dr—
The difference of each pair of horizontal distances calculated to the same elevation surface, mm; -The number of opposite observation differences, n≥4;
D,The average value of horizontal distance
8 Arrangement and submission of distance measurement data
Weather measurement at both ends
（30）
·（31）
（32）
8.1 In order to facilitate the long-term preservation and use of distance measurement data, it should be calculated accurately, annotated clearly, formatted uniformly, neatly and beautifully, and bound into a book. 8.2 The submitted data after arrangement should include the following contents: Survey task book: fill in the survey unit, operation time, personnel list and major event records and personnel and instrument accidents, etc. The format a.
As shown in Appendix A ( Appendix for suggestions).
Measurement distribution outline, its format is as Appendix B (Appendix for suggestions). b.
Operation requirement registration form: the content includes the name and number of the implementation standard, the technical requirements for distance measurement operation (including the electronic notebook program), and its format is as Appendix C (Appendix for suggestions).
d. Observation notebook, its format is as Appendix D (Appendix for suggestions), or the original record printout of the electronic field record and its copy, affixed to the notebook. Or data recording floppy disk and its printout. Observation results and accuracy statistics table, its format is as Appendix E (Appendix for suggestions). e.
Calibration certificate or its copy of the distance meter and meteorological instrument. Acceptance report, its format is as Appendix F (Appendix for suggestions). 9Maintenance and care of distance meter
GB/T 16818--1997
9.1 The rangefinder should be protected from moisture, dust, rain and sunlight during use, transportation and storage. It is generally not suitable for use and storage in an environment with a high temperature above 40℃ and a low temperature below -15℃. 9.2 During use, it should be strictly protected from rain. If it is slightly wet, it should be wiped dry with a clean soft cloth immediately. After use, it should be placed in a ventilated place to air for a period of time before it can be packed and stored.
9.3 After each use, the box and the instrument should be wiped with a soft cloth, dust and moisture should be removed, the internal battery should be removed, and the accessories should be checked. Are they complete? 9.4 When storing the instrument, it should be placed in a well-ventilated, dry and cool place, and moisture-proof and mildew-proof agents should be placed in the storage box. For instruments that are stored for a long time, they should be powered on regularly (for more than half an hour) (no longer than one month) to remove moisture, maintain and service, and check whether the instrument is working normally. 9.5 When storing the special battery of the rangefinder, it should be handled according to its instructions. For commonly used nickel-cadmium batteries, they must be stored with full power and charged regularly during storage.
9.6 It is not advisable to use highly volatile solutions or other organic solvents to clean the instrument. Generally, a mixture of anhydrous ethanol and ether (6:4) is used, and it is scrubbed with an absorbent cotton swab.
9.7 During use, non-maintenance personnel are strictly prohibited from disassembling various components of the instrument and arbitrarily adjusting components that should not be adjusted. 213/md
In the above formula: dr—
The difference of each pair of horizontal distances calculated to the same elevation surface, mm; -The number of opposite observation differences, n≥4;
D, the average value of horizontal distances
8 Arrangement and submission of distance measurement data
Weather measurement at both ends
（30）
·（31）
（32）
8.1 In order to facilitate the long-term preservation and use of distance measurement data, the calculation should be accurate, the annotations should be clear, the format should be unified, neat and beautiful, and bound into a book. 8.2 The data submitted after arrangement should include the following contents: Survey task book: fill in the survey unit, operation time, personnel list and major event records and personnel and instrument accidents, etc., the format a.
As Appendix A (suggested appendix).
Measurement distribution outline, the format is as Appendix B (suggested appendix). b.
Operation requirement registration form: the content includes the name and number of the implementation standard, the technical requirements for distance measurement operation (including the electronic bookkeeping program), and its format is as Appendix C (suggested Appendix).
d. Observation notebook, its format is as Appendix D (suggested Appendix), or the original record printout of the electronic field record and its copy, affixed to the notebook. Or data recording floppy disk and its printout. Observation results and accuracy statistics table, its format is as Appendix E (suggested Appendix). e.
Calibration certificate of distance meter and meteorological instrument or its copy. Acceptance report, its format is as Appendix F (suggested Appendix). 9 Maintenance and care of distance meter
GB/T 16818--1997
9.1 The distance meter should be protected from moisture, dust, rain and sunlight during use, transportation and storage. It is generally not suitable for use and storage in an environment with a high temperature above 40℃ and a low temperature below -15℃. 9.2 During use, avoid rain. If slightly wet, wipe dry with a clean soft cloth immediately. After use, place in a ventilated place to air dry for a period of time before packing and storing.
9.3 After each use, wipe the box and the instrument with a soft cloth, remove dust and moisture, remove the internal battery, and check whether the accessories are complete. 9.4 When storing the instrument, it should be placed in a well-ventilated, dry and cool place, and a moisture-proof and mildew-proof agent should be placed in the storage box. For instruments stored for a long time, they should be powered on regularly (no longer than one month) (for more than half an hour) to remove moisture, maintain and service, and check whether the instrument is working normally. 9.5 The special battery of the rangefinder should be handled according to its manual when stored. For commonly used nickel-cadmium batteries, they must be stored with full power and charged regularly during storage.
9.6 It is not advisable to use highly volatile solutions or other organic solvents to clean the instrument. Generally, a mixture of anhydrous ethanol and ether (6:4) is used and scrubbed with a degreased cotton swab.
9.7 During use, non-maintenance personnel are strictly prohibited from disassembling various parts of the instrument and arbitrarily adjusting parts that should not be adjusted. 213/md
In the above formula: dr—
The difference of each pair of horizontal distances calculated to the same elevation surface, mm; -The number of opposite observation differences, n≥4;
D, the average value of horizontal distances
8 Arrangement and submission of distance measurement data
Weather measurement at both ends
（30）
·（31）
（32）
8.1 In order to facilitate the long-term preservation and use of distance measurement data, the calculation should be accurate, the annotations should be clear, the format should be unified, neat and beautiful, and bound into a book. 8.2 The data submitted after arrangement should include the following contents: Survey task book: fill in the survey unit, operation time, personnel list and major event records and personnel and instrument accidents, etc., the format a.
As Appendix A (suggested appendix).
Measurement distribution outline, the format is as Appendix B (suggested appendix). b.
Operation requirement registration form: the content includes the name and number of the implementation standard, the technical requirements for distance measurement operation (including the electronic bookkeeping program), and its format is as Appendix C (suggested Appendix).
d. Observation notebook, its format is as Appendix D (suggested Appendix), or the original record printout of the electronic field record and its copy, affixed to the notebook. Or data recording floppy disk and its printout. Observation results and accuracy statistics table, its format is as Appendix E (suggested Appendix). e.
Calibration certificate of distance meter and meteorological instrument or its copy. Acceptance report, its format is as Appendix F (suggested Appendix). 9 Maintenance and care of distance meter
GB/T 16818--1997
9.1 The distance meter should be protected from moisture, dust, rain and sunlight during use, transportation and storage. It is generally not suitable for use and storage in an environment with a high temperature above 40℃ and a low temperature below -15℃. 9.2 During use, avoid rain. If slightly wet, wipe dry with a clean soft cloth immediately. After use, place in a ventilated place to air dry for a period of time before packing and storing.
9.3 After each use, wipe the box and the instrument with a soft cloth, remove dust and moisture, remove the internal battery, and check whether the accessories are complete. 9.4 When storing the instrument, it should be placed in a well-ventilated, dry and cool place, and a moisture-proof and mildew-proof agent should be placed in the storage box. For instruments stored for a long time, they should be powered on regularly (no longer than one month) (for more than half an hour) to remove moisture, maintain and service, and check whether the instrument is working normally. 9.5 The special battery of the rangefinder should be handled according to its manual when stored. For commonly used nickel-cadmium batteries, they must be stored with full power and charged regularly during storage.
9.6 It is not advisable to use highly volatile solutions or other organic solvents to clean the instrument. Generally, a mixture of anhydrous ethanol and ether (6:4) is used and scrubbed with a degreased cotton swab.
9.7 During use, non-maintenance personnel are strictly prohibited from disassembling various parts of the instrument and arbitrarily adjusting parts that should not be adjusted. 213
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