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GB/T 12898-2009 PDF in English


GB/T 12898-2009 (GB/T12898-2009, GBT 12898-2009, GBT12898-2009)
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GB/T 12898-2009: PDF in English (GBT 12898-2009)

GB/T 12898-2009
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 07.040
A 76
Replacing GB 12898-1991
Specifications for the third and fourth order leveling
ISSUED ON. MAY 06, 2009
IMPLEMENTED ON. OCTOBER 01, 2009
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 4 
1 Scope ... 5 
2 Normative references ... 5 
3 Terms and definitions ... 6 
4 Leveling network ... 7 
4.1 Elevation system and elevation reference ... 7 
4.2 Measurement accuracy ... 7 
4.3 Layout principles ... 8 
4.4 Benchmark layout density ... 8 
4.5 Line naming and benchmarking numbering ... 9 
4.6 Connection of new line and surveyed line ... 9 
4.7 Technical design of leveling network ... 10 
5 Point selection and stone burial ... 10 
5.1 Point selection ... 10 
5.2 Stone burial... 11 
6 Technical requirements of instrument ... 13 
6.1 Selection of instruments ... 13 
6.2 Instrument calibration ... 14 
6.3 Instrument technical indicators ... 15 
7 Leveling observation ... 16 
7.1 Observation methods... 16 
7.2 Survey station setting requirements ... 17 
7.3 Observation sequences and methods on survey stations ... 17 
7.4 Interval and detection ... 19 
7.5 Survey station observation tolerance, digits of reading, and settings ... 20 
7.6 Matters to follow during observation ... 22 
7.7 Observation of nodes... 23 
7.8 Detection made in connect leveling or adjoining leveling of new and old lines
... 23 
7.9 Round-trip observation height difference discrepancy and loop closure error
tolerance ... 23 
7.10 Repeated leveling and selection of leveling results ... 24 
8 Cross-river leveling ... 25 
8.1 Scope of application ... 25 
8.2 Provisions for leveling methods and tolerances ... 26 
8.3 Cross-river site selection and layout ... 26 
8.4 Cross-river leveling observation requirements ... 27 
8.5 Direct rule reading method ... 28 
8.6 Leveling on ice ... 29 
9 Electromagnetic distance measurement height traversing ... 30 
9.1 Scope of application ... 30 
9.2 Observation methods... 30 
9.3 Height difference calculation ... 31 
9.4 Measurement tolerance ... 33 
10 Records, arrangements, and calculations of field achievements ... 33 
10.1 Recording methods and requirements ... 33 
10.2 Field calculation ... 34 
10.3 Inspection and acceptance of field achievements and submission ... 36 
Appendix A (Normative) Drawing format of selected stone burial data and mark
stone fabrication and burial descriptions ... 38 
Appendix B (Normative) Instrument inspection method ... 58 
Appendix C (Normative) Cross-river leveling vane production and observation
records ... 83 
Appendix D (Normative) Observing handbook format and height difference
table compilation ... 86 
Specifications for the third and fourth order leveling
1 Scope
This standard specifies the principles for the establishment of the third and
fourth order leveling network, leveling methods, precision indicators and
technical requirements.
This standard applies to the deployment of the third and fourth order leveling
network.
2 Normative references
The provisions in following documents become the provisions of this Standard
through reference in this Standard. For the dated references, the subsequent
amendments (excluding corrections) or revisions do not apply to this Standard;
however, parties who reach an agreement based on this Standard are
encouraged to study if the latest versions of these documents are applicable.
For undated references, the latest edition of the referenced document applies.
GB/T 3161 Optical Theodolite
GB/T 10156 level
GB/T 12897-2006 Specifications for the first and second order leveling
GB/T 16818 Specifications for short to medium ranges electro-optical
distance measurements
CH/T 1001 General rules for technical summaries of surveying and mapping
CH 1002 Specifications for inspection and acceptance of surveying and
mapping products
CH 1003 Standard for quality assessment of surveying and mapping
products
CH/T 1004 General rules for technical design of surveying and mapping
CH/T 2004 The general rules of the electronic data recording for field
surveying
CH/T 2006 The electronic data recording rules for leveling
JJG 8 Specifications for leveling rule verification
JJG 425 Verification regulation of levels
JJG 414 Verification regulation of optical theodolite
JJG 703 Verification regulation of electro-optical distance meter (EDM
instruments)
JJF 1118 Calibration specification for global positioning system (GPS)
receiver
3 Terms and definitions
The following terms and definitions apply to this standard.
3.1
Node
The benchmark in the leveling network that connects at least three leveling
lines.
3.2
Leveling line
Leveling line between two adjacent nodes in the same order leveling network.
3.3
Section
Leveling line between two adjacent basic benchmarks in a leveling line.
3.4
Leveling section
Leveling line between two adjacent benchmarks.
3.5
Connect leveling
The observation of including a benchmark or other elevation point in a
leveling line.
3.6
stone every 4 km ~ 8 km; in densely populated and economically developed
areas, it can be shortened to 2 km ~ 4 km; in desert areas, the leveling branch
lines can be increased to about 10 km. The mark stone may not be buried when
the branch line length is within 15 km.
4.5 Line naming and benchmarking numbering
4.5.1 The leveling line uses the abbreviation of the starting and ending
geographical names as the line name, the order of starting and ending
geographical names shall be from west to east, and from north to south. As for
the ring name, it is composed of the geographical name of the largest place in
the ring followed by the letter “ring”. The grade of the third and fourth order
leveling lines are respectively represented by III and IV in front of the line name.
4.5.2 The benchmark on the line shall start from the starting benchmark of the
line, the point is numbered in the sequence of 1, 2, 3..., the point number
sequence along ring shall be clockwise, the points shall be numbered in the
sequence of number 1, 2, 3...
4.5.3 Leveling branch line is named by the surveyed elevation point name
followed by the letter “branch”. The benchmark stone of the branch line is
numbered in the sequence of number 1, 2, 3... along the direction from the
starting benchmark to the surveyed elevation point.
4.5.4 When using the old benchmark, the old benchmark name and number
shall be used. If it is really necessary to renumber it, the new name shall be
followed by a bracket to indicate the name of the benchmark where it was buried.
4.6 Connection of new line and surveyed line
4.6.1 The starting point and end point of the newly established leveling line shall
be the benchmarks of the surveyed higher or equivalent order leveling line.
4.6.2 When the newly established third and fourth order leveling line is within 4
km away from each surveyed equivalent benchmark, it shall be subject to
connect leveling or adjoining leveling. In case of adjoining leveling, it shall check
the surveyed benchmarks in accordance with the provisions of clause 7.8.
4.6.3 For the adjoining leveling of the benchmarks on the surveyed line, it shall
be performed in accordance with the requirements of the lower level accuracy
of the newly surveyed line and the surveyed leveling line.
4.6.4 When the new line is coincident with the surveyed line, if the old mark
stone complies with the requirements, it shall use the old mark stone as far as
possible. If the old mark stone does not meet the requirements, it shall select
A.6 of Appendix A. The protection wellbore wall shall not interfere with the
survey of the lower mark.
b) For the leveling mark stones buried in institutions, schools, residential
buildings, and cultivated land and water network areas, it shall build the
protection well and add the protection cover in accordance with the
specifications in A.6 of Appendix A.
c) In open areas such as forests, grasslands, deserts, and Gobi, in addition
to the construction of protective wells and protective cover as required,
two or three bearing pickets may be set up nearby, or small targets may
be constructed.
d) For mark stones buried in the mountains and forest areas, the bearing
pickets can be installed on the roadside closest to the benchmark. Bearing
pickets and targets can be made of wood, stone, concrete or metal
materials. The benchmark number and location direction are marked at
an eye-catching position by the use of red paint or embossing method.
Indicate the direction and distance of the laid topographic marker in the
description of benchmark.
5.2.4 Control of key processes
At the site where the mark stone is buried, the following photographs shall be
taken.
a) The photographs of the mark stone pit, which shall reflect the shape and
size of the mark stone pit and foundation pits;
b) Photographs of mark stone placement, which shall reflect the shape and
size of the mark stone;
c) The photographs of mark stone after trimming, which shall reflect whether
mark stone trimming is normalized;
d) The prospective photographs of the burial location of the mark stone,
which shall be able to reflect the features and geomorphological
landscape of the burial location of the mark stone.
5.2.5 Land occupation and hosting of mark stones
5.2.5.1 The land occupied by the mark stone shall obtain the consent of the
land management department and the land user organization or individual.
5.2.5.2 During the process of mark stone burial, the statutory duties and
precautions for the protection of measurement marks shall be publicized to the
local people and cadres. At the end of the mark stone burial, the relevant
governmental departments at the local township or above shall go through the
a) The black side of the rear view scale (basic division);
b) The black side of the front view scale (basic division);
c) The red face of the front view scale (auxiliary division);
d) The red face of the rear view scale (auxiliary division).
7.3.1.2 The leveling division sequence of the fourth order leveling scale for each
survey station is.
a) The black face of the rear view scale (basic division);
b) The red face of the rear view scale (auxiliary division);
c) The black face of the front view scale (basic division);
d) The red face of the front view scale (auxiliary division).
7.3.1.3 The optical micrometer method is used for survey station observations.
The operating procedure of a survey station is as follows (taking the third order
leveling as an example).
a) First level the instrument (When the bubble-type level instrument
telescope rotates around the vertical axis, the separation of the image at
both ends of the leveling bubble shall not exceed 1 cm. The circular bubble
of the automatic leveling instrument shall be located at the center of the
indicator ring);
b) Position the telescope on the black surface of the rear view scale, use the
tilt screw to adjust the leveling bubble to center accurately, read the scale
reading accurately in accordance with the stadia wire and central wire (for
the fourth order observation, it may not read the reading of the upper and
lower wires, but read the distance directly);
c) Rotate the telescope to aim the black face of the front view scale, and
operate in accordance with item b);
d) Aim the red face of the front view scale and operate in accordance with
item b).
e) Rotate the telescope to aim the red face of the rear view scale, and
operate in accordance with item d).
When using a single-row Invar scale for observation, the single-row division is
subject to two times aiming reading to substitute basic & auxiliary division
reading.
7.3.2 Digital level observation
7.3.2.1 The aiming scale sequence of each survey station by the round-trip
survey of the third order leveling is as follows.
a) Rear view scale;
b) Front view scale;
c) Front view scale;
d) Rear view scale.
7.3.2.2 The aiming scale sequence of each survey station by the round-trip
survey of the fourth order leveling is as follows.
a) Rear view scale;
b) Rear view scale;
c) Front view scale;
d) Front view scale.
7.3.2.3 The operating procedure for a station is as follows (taking a third order
leveling as an example).
a) First level the instrument (the telescope rotates around the vertical axis,
and the circular bubble is always at the center of the index ring);
b) Align the telescope with the rear view scale, use the vertical wire to aim
the center of the bar code, accurately make focusing until the bar code
image is clear, press the measurement key;
c) After readings are displayed, rotate the telescope to the center of the front
view bar code, accurately make focusing until the bar code image is clear,
press the measurement key;
d) After readings are displayed, re-aim the front view scale, press the
measurement key;
e) After the readings are displayed, rotate the telescope to the center of the
rear view bar code. Accurately make focusing until the bar code image is
clear, press the measurement key, to display the survey station results.
After the survey station passes inspection, transfer the station.
7.4 Interval and detection
7.4.1 In case of interval of observations, it is best to end the observation at the
benchmark. Otherwise, it shall select two fixed points which are stable and
- Operate in accordance with the instruction manual of the instrument.
7.6 Matters to follow during observation
7.6.1 At 30 min before the observation, the instrument shall be placed in the
shadow of the open air, so that the instrument tends to be in line with the outside
temperature; when setting up the survey station, the umbrella shall be used to
shield the sunlight; when moving the survey station, the instrument shall be
covered. Before using a digital level, it shall also be warmed up, which is not
less than 20 single leveling.
7.6.2 For a bubble type level, the leveling zero point of the tilt screw shall be
measured and marked before the observation. The zero position shall be
adjusted at any time as the temperature changes. For the level of the automatic
leveling instrument, it shall be strictly leveled before the observation.
7.6.3 When the tripod of the leveling instrument is to be placed on successive
survey stations, the two feet shall be parallel to the direction of the leveling line,
and the third foot shall be alternatively placed on the left and right sides of the
line direction.
7.6.4 Except for the turning of the line, the three positions of the instrument and
the front and rear view scales at each survey station shall approach a straight
line.
7.6.5 The scale stake (platform) shall not be placed in a pit in order to increase
the reading of the scale.
7.6.6 The number of survey stations for the direct observation and reversed
observation for each leveling section shall be an even-number. When changing
from direct observation to reversed observation, the places of the two scales
shall be switched, and the instrument shall be reset.
7.6.7 When performing the third order and fourth order leveling in the areas of
large height difference, it shall use the DS3 grade above instrument and scale
to make leveling as far as possible.
7.6.8 When rotating the instrument’s tilt screw and micrometer drum, its final
rotation direction shall be precession.
7.6.9 For digital leveling instruments, avoid the telescopes from direct aiming to
the sun; try to avoid shielding of the line of sight; the shielding shall not exceed
20% of the intercept of the scale in the telescope; the instrument can only work
within the temperature range specified by the factory; the measuring key cannot
be activated until the vibration caused by the vibration source has disappeared.
7.3.2.1 The aiming scale sequence of each survey station by the round-trip
survey of the third order leveling is as follows.
a) Rear view scale;
b) Front view scale;
c) Front view scale;
d) Rear view scale.
7.3.2.2 The aiming scale sequence of each survey station by the round-trip
survey of the fourth order leveling is as follows.
a) Rear view scale;
b) Rear view scale;
c) Front view scale;
d) Front view scale.
7.3.2.3 The operating procedure for a station is as follows (taking a third order
leveling as an example).
a) First level the instrument (the telescope rotates around the vertical axis,
and the circular bubble is always at the center of the index ring);
b) Align the telescope with the rear view scale, use the vertical wire to aim
the center of the bar code, accurately make focusing until the bar code
image is clear, press the measurement key;
c) After readings are displayed, rotate the telescope to the center of the front
view bar code, accurately make focusing until the bar code image is clear,
press the measurement key;
d) After readings are displayed, re-aim the front view scale, press the
measurement key;
e) After the readings are displayed, rotate the telescope to the center of the
rear view bar code. Accurately make focusing until the bar code image is
clear, press the measurement key, to display the survey station results.
After the survey station passes inspection, transfer the station.
7.4 Interval and detection
7.4.1 In case of interval of observations, it is best to end the observation at the
benchmark. Otherwise, it shall select two fixed points which are stable and
7.7 Observation of nodes
7.7.1 When observing to the nodes of the leveling network, it shall make
detailed records of the adjoining leveling in the observation handbook, the node
adjoining leveling is in accordance with A.3.
7.7.2 Nodes located in the ground deformation area shall be subject to adjoining
leveling with the local deformation observation network.
7.7.3 Nodes located in areas with large deformation shall be subject to
cooperative work by several observation groups to minimize the adjoining
leveling time.
7.8 Detection made in connect leveling or adjoining leveling
of new and old lines
7.8.1 When the newly established leveling line is subject to connect leveling or
adjoining leveling with the surveyed benchmark, if the observation time interval
of this benchmark exceeds 3 months, it shall be detected.
7.8.2 When the third and fourth order leveling lines (or branch lines) are subject
to connect leveling with the surveyed benchmarks, it shall detect a surveyed
leveling section in single trip. If the results of the single-trip detection exceed
limits, it shall detect the other single trip of this leveling section. If it still exceeds
limit, it shall continue forwarding detection, to determine a stable and reliable
surveyed point as the connect point. If the intersection point changes, it shall
make repeated leveling of the relevant leveling section.
7.8.3 The detection of higher order leveling line shall be conducted in
accordance with the order of the newly established line; the detection of lower
order leveling line shall be conducted in accordance with the order of the
original leveling line.
7.9 Round-trip observation height difference discrepancy and
loop closure error tolerance
7.9.1 The round-trip observation height difference discrepancy, the tolerance of
the difference between the loop closure error and the detected height difference
shall not exceed the requirements of Table 9.
meanwhile the discrepancy between its mean and the originally surveyed
height difference of the other single-trip does not exceed tolerance, the
mean of this same direction is taken as the height difference of this single
trip. If it exceeds the above tolerance, the other single trip shall be subject
to repeated leveling.
b) In single-trip double-turn point observation, when the discrepancy
between the height differences of the right and left lines of the leveling
section exceeds tolerance, it may perform repeated leveling for a single-
trip single line, and take the mean of it and one of the original survey result
which complies with tolerance requirements; if both the results of the
repeated leveling and the original leveling comply with tolerance
requirements, take the mean of the three single line results. When both
the results of the repeated leveling and the two single line results of the
original leveling exceed limit, it shall analyze the causes and perform the
repeated leveling for a single-trip single line.
c) When the accident error square error MΔ per kilometer leveling which is
calculated from the discrepancy of the round-trip height difference (or left-
right line height difference) exceeds the limit, some of the leveling sections
with large discrepancy values shall be subject to repeated leveling.
d) When the loop closure error exceeds the limit, it shall perform repeated
leveling against the leveling section of lower reliability (a large discrepancy
in the height-difference of round-trip observation or that which is poor in
observation conditions). When the annexed line closure error exceeds
limit, it shall analyze the causes and re-survey the relevant leveling
sections. In areas of large height difference, it should include the gravity
anomaly correction.
8 Cross-river leveling
8.1 Scope of application
When the leveling line spans rivers (or lakes, wide gullies, depressions, valleys,
etc.) and the sight line length is within 200 m, general observation methods may
be used, but the height of the instrument shall be changed once at the survey
station to make two observations. The difference between the two height
differences shall not exceed 7 mm, take the median of the two results. If the
length of line of sight exceeds 200 m, the method described in this clause shall
be used for observation in accordance with the length of sight and equipment
and other conditions.
It shall not be excessively inclined or swing.
e) After completion of one observation, it shall suspend for 15 min ~ 20 min,
then start the next observation.
f) Before the start of cross-river observation, a round-trip leveling shall be
conducted between the common leveling stones (or fixed points) on both
sides of the river and the scale points, as a benchmark for detecting the
change of the scale points. Before the start of the daily work, it shall
perform one single-trip detection, the results shall comply with the
detection tolerances as specified in 7.9. If it confirms that the scale point
changes, it shall reinforce the scale point to perform the cross-river
leveling observation again.
8.5 Direct rule reading method
8.5.1 Observation methods
The observation method of each observation set is as follows.
a) After leveling the leveling instrument at the center of the points I1 and b1
(or I2 and b2) and at the point in same distance from I1 and b1, use the
same scale to determine the height difference I1b1 in accordance with the
general operating procedure.
b) Move the instrument to point I1. After leveling the instrument precisely, aim
the near scale on the b1 point of the bank, read the basic & auxiliary
division once based on central wire.
c) Turn the instrument to aim the far scale on the I2 point of the opposite bank.
After adjusting the focus, use the tape to fix the focusing screw, read the
basic & auxiliary division twice, respectively, based on central wire.
d) Immediately move the instrument to point I2 on the opposite bank,
ensuring that the focusing screw is not touched. Meanwhile move the
scale on point b1 to point I1. After leveling the instrument precisely, first
aim the far scale at point I1 on the opposite side, take readings based on
the reversed sequence of c), b), a) and the operating requirements.
e) Move the instrument to between I2 and b2 and at equal distances. Measure
the height difference hI2b2 between I2 and b2 in accordance with the normal
operation method.
The above a), b), and c) are for the first half observation, d) and e) are for the
second half observation.
as those for the corresponding order of leveling.
9 Electromagnetic distance measurement height
traversing
9.1 Scope of application
In the mountainous areas and swamps and water network areas where
geodetic leveling is difficult, the fourth order leveling lines or branch line may be
subject to leveling by electromagnetic distance measurement height traversing
wires (hereinafter referred to as height traversing).
9.2 Observation methods
9.2.1 Before height traversing, it shall select the survey stations along the line.
The length of sight line is generally not more than 700 m, the maximum length
does not exceed 1 km, the vertical angle of line of sight shall not exceed 15’.
The height of line of sight and the distance from the obstacle shall not be less
than 1.5 m.
9.2.2 The height traversing may be arranged for the line that each aiming point
is arranged with instrument for opposite direction observation (hereinafter
referred to as establishing survey station at each point); it may also be arranged
for the line that the instrument is placed at every other aiming point (hereinafter
referred to as establishing survey station at every other point). In case of
establishing survey station at every other point, it shall use the single-trip
double-leveling method, that is, make two observations for each station by
changing the height or location of instrument, the difference between the front
and rear sight line length shall not exceed 100 m.
9.2.3 In case of distance measurement by electromagnetic distance meter,
preparation of distance measurement, observation methods and operation
requirements, meteorological element determination, record of results and
repeated leveling selection, calculation of correction value of meteorology,
additive constants, multiplicative constants, and the edge length reduction shall
be in accordance with the corresponding provisions of GB/T 16818.
9.2.4 Technical requirements and observation tolerances for distance
measurement are as follows.
a) Observation of the slant distance and vertical angle shall be performed
with clear imaging and stable signal;
Appendix B
(Normative)
Instrument inspection method
B.1 Visual inspection of scale
B.1.1 Whether the scale has dents, cracks, bumps, scratches, paint stripping and so
on.
B.1.2 Whether the scale marking line is clear and whether there is any abnormal flaw.
B.2 Calibration of circular level on leveling scale
B.2.1 Place a leveling scale on a ruled peg approximately 50 m away from the leveling
instrument so that the centerline (or edge) of the leveling scale coincides exactly with
the vertical wire of the telescope. If the air bubble on the scale deviates, use the
correction pin to guide the circular level bubble of the scale to the center.
B.2.2 Rotate the leveling scale for 180° so that the centerline (or edge) of the leveling
scale accurately coincides with the vertical wire of the leveling instrument. Observe the
air bubble. If the bubble is centered, it means that the surface of the scale is vertical.
Otherwise, it shall calibrate the cross wire of the leveling instrument again.
B.2.3 Rotate the leveling scale for 90° to check if the other side of the scale is vertical.
The method of calibration is the same as B.2.1, B.2.2.
B.2.4 Repeat such calibration for many times, so that the scale can be accurately
positioned in a vertical position in accordance with the circular level on the scale.
B.3 Determination of division plane bending difference of leveling scale
B.3.1 Determination method
A thin straight line is drawn at both ends of the scale, measure the distance from the
division plane to this thin line from both ends and center of the scale surface.
B.3.2 Calculation method
The scale bending difference f is calculated in accordance with formula (B.1).
f = R center - (R upper + R lower)/2 ...(B.1)
Where.
R center - Center reading, in millimeters (mm);
B.5.1 Preparation
Select to perform this inspection in a stable temperature room. Place the third order
standard metal linear scale or same accuracy of inspection scale and the leveling scale
under detection at the place of detection. During detection, the leveling sc......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.