Some standard content:
National Standard of the People's Republic of China
Specification for offshore observations
The specificatian for offshore observations 1 Subject content and scope of use
GB/T 14914—94
This standard specifies the items, technical requirements, methods and data processing of offshore hydrological and meteorological observations. This standard is applicable to marine observation stations (referred to as observation stations) on coastal and island platforms for offshore hydrological and meteorological observations. 2 Reference standards
GB4696 Navigation aids in waters of China
GB12460 Application record format of marine data
GB12898 National third and fourth level wall measurement specifications ZBA24002 Code of China's marine observation stations Part I General
3 Basic requirements
3.1 The data obtained from offshore observations should be able to reflect the basic characteristics and changing laws of the environment of the observed sea area. 3.2 Coastal observations include observations of hydrological and meteorological elements and data processing. 3.3 The observation items of the station and their measurement accuracy, observation points (fields) shall not be changed at will once determined. 4 Observation items, time and procedure
4.1 Observation items
4.1.1 Hydrological items: tides, waves, surface seawater temperature, surface seawater salinity, sea luminescence, sea ice, etc. 4.1.2 Meteorological items: wind, air pressure, air temperature and humidity, effective visibility on the sea surface, precipitation, fog, etc. 4.2 Observation time
4.2.1 The seaside observation shall be conducted in Beijing time. 4.2.2 The tides, waves, surface seawater temperature and salinity, sea ice shall be based on 24:00 (excluding 24:00) Beijing time as the daily boundary, and sea luminescence shall be based on 20:00 (including 20:00) Beijing time as the daily boundary; the meteorological items shall be based on 20:00 (including 20:00) Beijing time as the daily boundary. 4.2.3 The tide height shall be measured at the hour of each day, and the daily high tide and low tide height and their corresponding time shall also be measured. 4.2.4 Waves should be observed at 02:05:08, 11:00, 14:00, 17:00 and 20:23 daily. Observation stations that are not equipped to observe waves at night should observe at 08:00, 11:00, 14:00 and 17:00. In winter, when it is not convenient to observe at 17:00 due to the dark sky, the observation time can be set in advance according to the actual situation and noted in the remarks column of the observation record book. 4.2.5 Surface seawater temperature should be observed at 08:00, 14:00 and 20:00 daily. 4.2.6 Surface seawater salinity should be observed at 14:00 daily. 4.2.7 Sea luminescence should be observed after dark every day. 4.2.8 Sea ice should be observed at 08:00 and 14:00 daily. The thickness and temperature of sea ice and the ice chart drawing instrument should be observed on May, October, 15, 20, 25 and at 08:00 at the end of each month. CB/T 14914-94 4.2.9 The effective visibility, pressure, air temperature and humidity of the sea surface should be observed at 08:00, 14:00 and 20:00 daily. The precipitation should be observed at 08:20 daily. 4.2.10 Wind and fog should be observed continuously every day. 4.3 Observation of floating ice during severe ice period
4.3.1 During severe ice period each year, representative sea ice measuring points should be selected to conduct discontinuous observations of sea ice thickness, temperature, salinity, density, strength, ice ridges and other elements one to two days each time. At the same time, routine observations of other sea ice elements should also be conducted. 4.3.2 During the observation, surface seawater temperature and salinity and related meteorological elements should be observed at the same time. 4.4 Observation procedures and supplementary measurement regulations
4.4.1 The observation procedures are arranged by each station, but all scheduled observation items (except sea ice) should be completed within 30 minutes before the exact time, and sea ice observations can be completed within one hour after the exact time. Meteorological monthly observations should be arranged as much as possible within 15 minutes before the exact time, air pressure observations should be close to the exact time, and tide calibrations should be conducted on the hour. 4.4.2 During observation, if the instrument cannot be used for some reason, other methods should be used for observation. The observation data can be used as formal records, and the method and reason should be explained in the remarks column.
4.4.3 If a certain item or a certain requirement cannot be observed within the specified observation time, it can be remeasured within · hours (two hours of sea ice) after the exact time. If the sea ice thickness, temperature observation and ice condition map mapping cannot be carried out within the specified remeasurement time, remeasurement can be carried out at the same time on the next day; all remeasurement contents are still used as formal records. The reason and time of remeasurement should be noted in the remarks column of the observation record book. Items or elements that cannot be remeasured within the remeasurement time shall be treated as missing. 5 Observation of disaster process
5.1 When the wind speed or wave height reaches a certain value (the value should be determined according to the specific conditions of each sea area), wave observations should be intensified to once an hour.
5.2 When earthquake tsunamis or storm surges affect the local area and the instruments and equipment cannot be used for normal tidal measurements, the observers must monitor the tidal level changes to obtain complete tidal data. 5.3 The observers should record various marine disaster processes, conditions and abnormal phenomena near the observation station. 6 General Provisions
6. 1 The observers should calibrate the observation clocks at 07:00 and 19:00 every month. The error of the clocks within 24 hours shall not exceed 1 minute. 6.2 Before observation, the observers should inspect the observation points (fields) and the instruments and equipment used. 6.3 The observation instruments and equipment used for seashore observation must be qualified products approved by the relevant functional departments of the state. The instruments and equipment imported from abroad must be identified by the relevant national institutions and confirmed to be of qualified quality before they can be used. The instruments and equipment used must be within the validity period of the calibration, and the instruments and equipment that exceed the inspection shall not be used. The instruments and equipment should be regularly inspected, maintained and maintained. Failures should be promptly eliminated or replaced, and the record should be noted in the preparation column of the observation record book.
6.4 All observation data should be recorded immediately in the observation record sheet (see Appendix A (Supplement) 7 or filled in on the self-recording paper, and written with a black pencil of moderate hardness. The handwriting should be neat and clear, and no erasures are allowed. If there are errors in the record, correct them with a black pencil if you find them yourself, and correct them with a blue-black or pure black pen if you have proofread them. When correcting, cross out the original recorded data and write the correct data in the upper right corner. Items or elements that are missing should be marked with the symbol " " in the relevant column, and suspicious recorded data should be enclosed in brackets "()". 6.5 The observation station should record the relevant materials of the seashore observation work and organize and file them for safekeeping. Part II Tidal Observation
7 Terminology
7.1 Tide
CB/T14914—94
Tidal Induction by Celestial Bodies The phenomenon of periodic fluctuation of the sea surface caused by the action of the force. 7.2 Tidal height datum
The zero surface from which the tide height is calculated.
7.3 Tidal height
The vertical distance from the sea surface to the tidal height datum. 7.4 Tide time
The moment when a certain tide height appears.
7.5 High tide
The highest tide level in a cycle of tidal fluctuation. 7.6 Low tide
The lowest tide level in a cycle of tidal fluctuation. 7.7 Stop tide
In the period before and after the low tide, the sea surface is in a state of equilibrium without rising or falling. 7.8 Slack tide
In the period before and after the high tide, the sea surface is in a state of equilibrium without rising or falling. 8 Technical requirements
8.1 Observation elements
Altitude measurement at the whole hour, high and low tide heights, high and low tide times. B. 2 Units and accuracy of tidal height measurement
The unit of tidal height measurement is centimeter (cm). The accuracy is stipulated in three levels: level one is ±1cm; level two is ±5cm; level three is ±10cm. 8.3 Selection of observation points
The observation point should be selected at a water depth of 1-2 at the lowest tide; it should be connected to the open sea, with a stable water flow, not easy to silt up, and with small wave noise; it should avoid severely eroded and easily collapsed coasts, and make use of breakwaters, docks, piers and other marine structures as much as possible. 8.4 Setting of hydraulic push points and leveling
8.4.1 Setting of leveling points
The survey station should set up a basic leveling point and up to two calibration leveling points at appropriate locations. The basic leveling point is a permanent elevation control point of the survey station. The calibration leveling point is used to guide the survey and check the zero point of the water gauge. .The leveling points, basic leveling points and verification leveling points of the reading pointer elevation shall be buried according to the burying methods of basic leveling stones and ordinary leveling stones, and strict protection measures shall be taken to prevent them from being damaged. The technical design, point selection, burying method and requirements of the leveling stone burial shall be implemented in accordance with the provisions of GB12898, and shall be recorded and archived in detail.
8.4.2 Leveling basis of leveling points
: Basic leveling points shall be connected with the national first-class leveling measurement requirements and the national water and elevation system; b. Verification leveling points shall be connected with basic leveling points according to the national third-class leveling measurement requirements; c. Basic leveling points and verification leveling points shall be re-measured once a year after they are put into use. If no elevation changes are found after two years, basic leveling points shall be re-measured every four noons, and verification leveling points shall be re-measured every two years: d.The measurement of leveling points shall be carried out in accordance with the relevant provisions of GB12898, and the situation of each measurement and re-measurement shall be recorded and filed in detail. 8.5 Determination of tidal height datum surface
8.5.1 The tidal height datum surface of the measuring station is the lowest possible low tide surface in the local area determined by the method of calculation. For measuring stations where the lowest possible low tide surface in the local area has not been determined, the horizontal surface at the zero point of the first water level at the beginning of the observation or a certain horizontal surface can be used as the tidal height datum surface temporarily. After one year of observation, the measured data should be used to determine the lowest possible low tide surface in the local area as the tidal height datum surface of the measuring station through calculation, referred to as the measuring station datum surface. 8.5.2 Once the measuring station datum surface is determined, it cannot be easily changed. The process of determining the measuring station datum surface should be recorded and filed. 8.5.3 After the station base is determined, the tidal height data of the station must be corrected to the station base. 8.6 Design of Tide Wells
GB/T 14914--94
Tide wells are buildings specially designed for observing tides. Their construction must meet the requirements that the difference in tidal level between the well and the outside of the well is less than 1cm, and have good wave absorption performance. For the design of tide wells, see Appendix B (Supplement). The design of tide wells should be recorded and archived in detail. 8.7 Water gauges inside and outside the well
8.7. 1 Requirements and installation
a. The minimum scale of the water gauge outside the well is 1cm. The cumulative error of the ruler length is not more than 0.5cm; h. The minimum scale of the water gauge inside the well is 1mm, and the cumulative error of the ruler length is not more than 5mm; c. For the installation and maintenance of the water gauge, see Appendix C (Supplement). 8.7.2 Leveling
a. Before the newly installed or replaced external well water gauge is used, it should be measured with the calibration water point according to the requirements of the national fourth-class leveling survey to determine the elevation of the zero point of the water gauge. It should be re-measured every six months. When the external water gauge is hit by a typhoon, hit by a ship, or the water gauge plate is replaced or adjusted, or it is believed that the water gauge may be loose, the zero point elevation of the water gauge must be re-measured:
C. After the installation of the internal well water gauge reading pointer, it should be measured with the calibration water point according to the requirements of the national fourth-class leveling disk to determine the elevation of the reading pointer. It should be re-measured every six months.
8.7. 3 Comparative observation
The internal and external water gauges should be compared and observed once a month. During the observation, the comparison observation should be made once at high tide, mid tide, and low tide, and at least three pairs of values should be read each time.
8.7.4 Inspection, adjustment or replacement
For newly installed well water gauges, the length change should be checked every quarter. If there is no change after one month, it can be checked once a quarter.
b. When the zero point of the external water gauge changes, the expansion and contraction of the well water gauge, or the elevation change of the reading pointer is equal to or greater than 1.0cm, it should be replaced or adjusted in time. The inspection method for the zero point of the well water gauge and the elevation change of the well water gauge reading pointer is shown in Appendix D (Supplementary). 8.7.5 Records
The installation, measurement, inspection, comparison, adjustment, replacement, and change of the well water gauge, the external water gauge, and the reading pointer must be recorded and filed in detail.
9. Observation method
Tides can be observed by using float-type, pressure-type, acoustic-type tide gauges or water gauges. Tide gauges need to be built when using float-type tide gauges for observation, and tide gauges are generally not required when using other tide gauges for observation. The observed tide time is recorded to the minute, using the four-digit timekeeping method, such as 8:15, which is recorded as 0815.
9.1 Tide gauge observation
9.1.1 Calibration of high tide recording
During observation, the internal and external water gauge and observation clock should be used for calibration. 9.1.1.1 Using analog curve recording
a. According to the measurement accuracy level, the calibration time is: first level calibration every 12 hours; second level calibration every 24 hours, first level calibration every 48 hours: each calibration should be carried out at the top of the hour; b. During calibration, a pencil should be used to draw a line about 1 cm long and perpendicular to the time line at the tip of the self-recording pen (if affected by waves, at the middle position of the pen tip change), and the water gauge value of the tide height should be noted on the right side, and the tide time should be noted on the left side. 9.1.1.2 Using data recorder
a, calibrate at least once every half month, and the calibration work should be carried out at the hour; b during observation, if the error is found to be greater than the accuracy requirement, the cause should be found in time, the instrument should be adjusted, and the situation should be recorded in detail. 9.1.2 Replacement of recording medium
GB/T 14914—94
9.1.2.1 Replace the analog curve recording paper immediately after calibration. Fill in the relevant columns on the recording paper before replacement. After replacement, calibrate the tide height and tide time again, and note the calibration results on the recording paper. Continue to observe for 5 minutes to check whether the instrument can record normally. When changing paper, avoid high tide. Low tide, the paper change time can be appropriately delayed. If the flat (stop) tide time is long, there is no need to wait. 9.1.2.2 Replace the data recording paper or other recording medium on time, and indicate the number and start and end time on the medium. 9.2 Water gauge observation
9.2.1 Water gauge observation is carried out at the top of the hour every day. H should be observed every 10 minutes within half an hour before and after high and low tide (if the flat tide or the tidal period is long, it should be observed 1 hour before and after high and low tide). 9.2.2 Parallax should be reduced during observation; if there is wave influence, the middle value of the two wave crests and troughs should be read continuously, and the average value should be taken as the observation value of this time.
9.2.3 Water gauge zero point refers to the starting point for observing the sea level with a water gauge. When the sea level drops below the water gauge zero point, read the distance from the water gauge zero point to the sea surface, and record this value with a negative sign "-". 10 Arrangement of observation records
10.1 Arrangement of simulation curve records
10.1.1 Check of records
1. Check whether the relevant columns of the record paper are missing or wrong: b. Check whether the tide time and tide height at the beginning of the curve are connected with the curve of the previous recording paper. 10.1.2 Curve correction
If the curve is interrupted and the interval of interruption does not exceed 3h, the interrupted part should be drawn and filled in with a pencil according to the development trend of the curve and with reference to the curve of the previous day; if the curve interruption is not at high or low tide, the drawn curve can be used as a formal record, if the interruption occurs at high or low tide, the drawn curve is used as a condensable record; if the interval of interruption exceeds 3h, it should be treated as missing measurement. Indicate the reason for the interruption on the back of the recording paper. b. Due to poor wave absorption performance, the curve is in the shape of a belt (including high and low tide periods). A smooth curve can be drawn in pencil in the middle of the curve belt as a formal record.
10.1.3 Correction of tidal time and height
10.1.3.1 Correction requirements
a. When the accuracy is level 1, if the error of tidal time is less than or equal to 1 min during the 12 hours between two consecutive calibrations, a tidal time correction should be made; if the error of tidal height is equal to or greater than 1 cm, a tidal height correction should be made; b. When the accuracy is level 2, if the error of tidal time is equal to or greater than 5 min during the 24 hours between two consecutive calibrations, a tidal time correction should be made; if the error of tidal time is equal to or greater than 3 min and the maximum tidal level difference between two consecutive hourly points is greater than 100 cm, a tidal time correction should be made; if the error of tidal height is equal to or greater than 2 cm, a tidal time correction should be made. c. When the accuracy is level 2, if the error of tidal time is equal to or greater than 10trin in the 48h between two consecutive calibrations, a tidal time correction should be made; when the error of tidal time is equal to or greater than 6min and the maximum tidal level difference between two consecutive hourly points is greater than 100cm, a tidal time correction should be made; if the error of tidal height is equal to or greater than 5cm, a tidal height correction should be made. 10.1.3.2 Correction order tidal time correction should be made first, followed by tidal height correction. 10.1.3.3 Correction method
Generally, the correction method is adopted, and the correction value is calculated by the following formula: D1 = K1 + D.
K1 = +-I(D - D.)t:
Formula, D1 is the correction value of tide time or tide height at time i + min or ctm; K1 is the error distribution value of tide time or tide height at time i between two consecutive calibrations, min or cm-(1
GB/T 14914-94
Dr is the error value of the previous calibration, min or cmD-I), and the error value of the next adjacent calibration, min or cm; D. or D, with positive or negative signs. When the self-recording clock is faster than the standard time, the tide time error is negative, otherwise it is positive; when the measured value of the tide height is less than the self-recording value, the tide height error is negative, otherwise it is positive. 1-the whole number of hours between two consecutive calibrations (such as 12h, 24h, etc.); t;-1 The whole number of hours from the calibration time (where /-0,1*23), when t12, and the calibration is at 08.20, such as 09 and 21:00, that is: -9 and i=21, then -1, t21-1, 10.1.4 Selection and correction of high and low tides 10.1.4.1. Selection method of high and low tides
Select high and low tides from the corrected record curve and mark them: the mark symbol for high tide is "\", and the mark symbol for low tide is "+". The high tide value is recorded on the right side of the mark and the tide time value is recorded on the left side; a
b. If the curve is relatively regular, high tide and low tide can be marked at the highest and lowest points respectively; if the time of flat tide or no tide is long and the curve is smooth, high tide or low tide can be marked in the middle of the flat tide or no tide curve c
During the period of flat tide or no tide, if the record curve rises (falls), the high and low tide marks are made at the highest (lowest) point. If the high and low tide appear during the period of changing the record paper, the two record papers are connected along the time series, and the high and low tide marks are made at the highest or lowest point respectively. In the mixed tide area or when there is a secondary vibration, the island line will show more fluctuations than the general rules. When the amplitude of the fluctuation exceeds 10cⅡ, f.
and the time exceeds 2 h, should be selected as a high tide or low tide. 10.1.4.2 Examples of selection of irregular high and low tides: a. Rising (falling) type, the highest (lowest) tide peak (valley) is used to read the tide time and tide height (see Figure 1); b. Biased peak (valley) type, the highest (lowest) peak (valley) is selected to read the tide time and tide height (see Figure 2) 1c. Parallel peak (valley) type, the width of the two peaks (valleys) is the same, and one of the peaks (valleys) can be selected according to the situation to determine the tide time and tide height of the high and low tides (see Figure 3 (a)] The width of the two peaks (valleys) is different, and the peak (valley) with the larger width is selected to read the tide time and tidal height [see Figure 3 (b); d. For multi-peak (valley) type, if there are multiple peaks (valleys), the high and low tides and tidal heights can be selected at the peak (containment) closer to the middle bone than the highest (low) tide peak (valley) with a height difference of no more than 1cm (see Figures 4 and 5). 10.1.4.3 Correction of high and low tides
a. According to the tidal time and tidal height correction values of the two adjacent whole points on both sides of the high and low tides, use the interpolation method to correct; b. If the high and low tides are exactly in the middle of the two adjacent whole points, the difference between the correction values of the two whole points is 1min or 1c m, use the correction value of the next hour for correction;
c. High and low tides appear at the time of paper change, and the correction value should be the correction value on the recording paper where the high (low) tide appears. 10.1.5 Correction of tidal height error caused by changes in the well water gauge or reading pointer 10.1.5.1 Correction requirements
a. If the difference in tidal readings between the well and outside the well is found to be equal to or greater than 1 cm, and it is confirmed that it is caused by changes in the well water gauge or reading pointer, the following corrections should be made:
b. If the error in the length product of the well water gauge is equal to or greater than 1 cm, the following corrections should be made: c. Use leveling to confirm that the reading pointer change is equal to or greater than 1cm, then it should be corrected. 10.1.5.2 Correction method
a. When the change of the water gauge or reading pointer can be determined and confirmed, it should be corrected according to the actual situation. b. When the cause and date of the change of the water gauge or reading pointer in the well cannot be confirmed, it can be interpolated from the last inspection to the time to be inspected.
10.2 Arrangement of data records
10.2.1 Data records should be corrected if the error is greater than the accuracy requirement. GB/T1491494
10.2.2 When the cause of the error can be determined, it should be corrected according to the actual situation. When the cause and date of the error cannot be confirmed, it can be interpolated from the last calibration to the time to be calibrated. 10.3 Arrangement of water gauge observation records
Sudden II (drop) type
Parallel peaks
Collation of peak (valley) type
b. Parallel valley
Figure Parallel bee (valley) type
CB/T 14914—94
Multiple peaks (valleys) type
Figure 5 Multi-peaks (valleys) type
Based on the water gauge observation records, use the corrected tidal height values to draw a simulation curve of the monthly tidal height changing with time on the calculation paper, and then select the tidal height and tidal time of high and low tides from the curve. Part III Wave Observation
11 Terminology
11-1 Waves
Wind waves and swells appearing on the sea surface are collectively referred to as waves. The waves generated by the direct action of wind are called wind waves. The waves transmitted from other sea areas, or the waves left after the local wind force decreases sharply, the wind direction changes or the wind subsides, are called swell waves. 11.2 Wave height
The vertical distance between adjacent wave crests and waves. 11.3 Period
The time interval between two adjacent wave crests or two waves passing through a certain fixed point is called the period of a wave. 11.4 Sea state
The surface characteristics under the action of wind.
11.5 Wave type
The appearance characteristics of the waves.
11.6 Wave direction
The direction from which the waves come.
12 Technical requirements
12.1 Observation elements
Wave height, period, sea state, wave type, wave direction. 12.2 Measurement units and accuracy
GB/T 14914—94
12.2.1 The unit of wave height measurement is meter (1m), with one decimal place, and the accuracy is specified as two levels, level one is ±10% and level two is ±15%. 12.2.2 The unit of period measurement is second (s), and the accuracy is ±0.58. 12.2.3 The unit of wave direction measurement is degree (\), and the accuracy is ±5°. 12.3 The sampling time interval and time length of the recording instrument The sampling time interval of the self-recording wave measuring instrument should be less than or equal to 0.5≤, and the number of waves recorded continuously should not be less than 100. The length of the recording time depends on the size of the average period, and is generally 17 to 20 minutes. 12.4 Selection of wave measuring points and observation sites
12.4.1 The sea surface at the observation point should be open, without the influence of obstacles such as islands, reefs, sandbanks, aquaculture and fishing areas, and try to avoid steep banks. 12.4.2 The water depth at the place where the buoy (or sensor) is deployed should not be less than half the wavelength of the common waves in the swimming area. The seabed should be flat and avoid the rapids as much as possible.
12.4.3 The observation site should be close to the observation point. The height of the optical wave measurement site above the sea should be 20~30m. 12.5 Instrument deployment and installation
The deployment and installation of instruments should be carried out according to the requirements of each instrument. After the sensor or wave measurement buoy is deployed, the water depth at the deployment point, the tide height at the time of deployment, the azimuth and horizontal distance of the deployment point relative to the observation site (or receiving point) on the shore must be measured immediately. The height from the seabed of the deployment point to the tide height reference plane is calculated using the formula:
D, = D h
Where: D—the height from the seabed of the deployment point to the tide height reference plane, m: D——the water depth of the deployment point at the time of deployment, m
h——the tide height at the time of deployment, m.
The measured parameters should be recorded and archived in detail. 13 Observation methods
13.1 Observation of sea conditions
Observe the signs of the visible sea surface outside the shore break zone by force, and judge according to Table 1 based on the shape of the wave crest, the degree of breaking and the amount of spray on the sea surface.
Table 1 Sea condition grade table
Sea condition (grade)
The sea surface is smooth as a mirror
The wind and waves are very small, and the waves are beginning to be broken, but the spray is not white
The wind and waves are not big, but very smooth, the wave crests are broken, and white spray is formed in some places. White waves
Sea condition (grade)
13.2 Observation of wave type
GB/T 14914---94
Continued Table 1
The wind and waves have obvious shapes, and white waves are formed everywhere
Tall wave crests appear, and the spray occupies a large area on the wave crest. The wind begins to shave off the waves on the crests. The waves shaved off by the wind on the crests begin to grow into strips on the wave slope. The strips of waves shaved by the wind cover the entire wave slope and reach the trough in some places. The dense strips of waves cover the entire wave slope, and the sea surface turns white. Only in some places in the trough there are no waves. The entire sea surface is covered with a dense layer of waves, and the air is filled with water droplets and foam. Visibility is significantly reduced. Observe the appearance of waves on the sea surface in a large area outside the surging wave belt with the naked eye, and determine the wave type according to Table 2, and record its symbol: there are no waves on the sea surface, and the wave type column is blank.
Table 2 Wave type classification table
Mixed waves
13.3 Observation of waves
Appearance of waves
Affected directly by wind, the wave crest is sharper, the wave crest line is shorter, the leeward side is stronger than the windward side, and there are often sprays and splashes on the wave bee. Under the action of inertia, the wave shape is smooth, the wave crest line is longer, the wave is obvious, and the slope is relatively steep. Wind waves and swell waves exist at the same time, and the difference between the height of wind waves and the height of swell waves is not much. Wind waves and swell waves exist at the same time, and the height of wind waves is obviously greater than the height of irrigation waves. Wind waves and swell waves exist at the same time, and the height of wind waves is obviously less than the height of pain waves. 13.3.1 Use instruments to measure the wave height of wind waves and swell waves respectively. 13.3.2 When only (swell) waves appear on the sea surface, the direction of (wind) waves is recorded as C. 13.3.3 If more than one wind (swell) wave system appears on the sea surface at the same time, only the wave direction of the main wave system shall be determined. 13.3.4 If there are no waves on the sea surface or there are waves but the wave quotient and period cannot be measured, record C in the wave direction column. If the wave height and period can be measured but the wave direction cannot be measured, record × in the wave direction column.
13.4 Observation of wave height and period
Observation of wave height and period includes characteristic values such as maximum wave height and its corresponding period, wave height of one tenth of the largest wave and its period, effective wave height and its period, average wave height and its average period. 13.4.1 Characteristic values of wave quotient and period and their codesa.
The maximum wave height (IImx) is the maximum value of the wave height in the continuous record of waves; its corresponding period is the maximum wave period (Tmx);b. The wave height of one tenth of the largest wave (H1t) is the average wave height of one tenth of the total number of wave heights in the continuous record of waves; its corresponding period average value is one tenth of the largest wave period (T);c. The effective wave height (II) is the average wave height of one tenth of the total number of wave heights in the continuous record of waves; its corresponding period average value is the effective wave period (T);d. The average wave height (H) is the average value of all wave heights in the continuous record of waves; its corresponding period average value is the average period (T). 13.4.2 Wave measurement method with self-recording wave meter
13.4.2.1 Determine the recording range of the instrument according to the water depth and sea conditions at the observation point, select the sampling time interval according to the requirements of Article 12.3, measure the wave height and period of no less than 100 waves within the sampling time (1720min), and take 100 consecutive waves to obtain the characteristic values or record the wave surface simulation curve.
13.4.2.2 When using the wave surface simulation curve to record, the measurement date, time, paper feed speed and range should be noted. 13.4.2.3 When the wave height reaches the height required for magnetic recording as specified by the measuring station, the original wave sampling data shall be transferred to a medium (tape, floppy disk) and labeled.
13.4.3 Wave measurement method using an optical wave meter on the shore
13.4.3.1 Observe the top of the buoy pole that jumps with the waves, measure the time required for 10 consecutive waves to pass through the buoy, repeat the measurement 3 times (the time interval between two consecutive measurements should be less than 1 minute), and divide the sum of the 3 measured times by 30 as the average period. 13.4.3.2 When 15 to 20 large waves pass through the buoy within 100 times the average period, measure the number of grids of the wave height scale (take a decimal place) that the top of the buoy pole drops from the wave crest to the wave trough. Then observe a series of continuous waves (generally 15-20) passing through the buoy, the average position of the top of the buoy pole jumping is read on the wave height scale 7, take one decimal place, in order to reduce the error, the d value should be read as much as possible when the wave is small.
13.4.4 Monthly measurement method
13.4.4.1 Select a representative fixed point on the sea surface F, visually observe the time required for 10 continuous waves to pass through a fixed point, repeat the measurement three times, and take the average value as the average period. 13.4.4.2 In the time of 100 times the average period, pay close attention to a fixed point on the sea surface, and estimate the tenth-large wave height and the maximum wave height.
14 Arrangement of observation records
14.1 Arrangement of self-recording records
When arranging the self-recording records of sea waves, the passband uses the zero-crossing method to determine the wave height and period. 14.1.1 Principles of pre-processing of self-records
Determine the "zero line" of the record. When the "zero line" has obvious drift, it should be carried out in sections: a.www.bzxz.net
Obviously wrong data records (singular points) should be eliminated and then reasonably processed; determine the upper zero points of the surface record;
d. Select 100 continuous or quasi-continuous waves in the wave surface record. 14.1.2 Arrangement of sampling data records
After calculating the wave height and corresponding period of each wave of the 100 waves selected after pre-processing (the total number of waves is 100), arrange them from the highest to the lowest according to the height, and calculate the maximum wave height, maximum wave period, one-tenth of the large wave height, one-tenth of the large wave period, effective wave height, effective wave period, average wave height, and average period.
14.1.3 Arrangement of simulation curve records
14.1.3.1 Correction of cycle
If the paper feed speed of the simulation curve recording paper is inconsistent with the specified paper feed speed, the read cycle should be divided by the correction value of the recording paper feed speed.
14.1.3.2 Calculate the wave height and cycle by the measurement method. Measure the wave height and cycle of the simulation curve of 100 waves selected after pretreatment one by one. Calculate various wave height and cycle characteristics according to the requirements of Article 14.1.2.
14.1.3.3 Calculate the wave height and cycle a by the maximum value method. Among the 100 wave simulation curve records selected after preprocessing, calculate the time interval t between the first upper span zero point and the last working span peak point and the number of upper span zero points Nh. Find the highest peak, lowest trough, second highest peak and second lowest trough in the wave surface record, and measure their heights from the zero line (all positive values); use the formula to calculate the effective wave height:
Where: Hs-
GB/T 14914---94
[K,(HA +He) + K,(H +H))]
K, = 21/29-1/3(1 + 0. 2898-1 - 0. 2478-2)-1K. = 21/80-/3(1 - 0. 2118-1 -- 0. 1038-*)-1B- LnN
-effective wave height + m #
the quotient of the highest point of a wave surface to the zero line, He—the height of the lowest point of the wave surface to the zero line, m; Hs-the height of the second highest point of the wave surface to the zero line, m; Hu—the height of the second lowest point of the wave surface to the zero line, m! K1, K,..wave height correction coefficient,
6——the natural logarithm of the number of times of crossing zero point, N
-the number of times of crossing zero point.
In the wave surface simulation curve record, find the maximum wave height and directly measure the maximum wave height value to calculate the average period;
T=t/(N- 1)
In the formula,
average period; 83
&…-the time interval between the first upper crossing zero point to the last upper crossing zero point of this observation record, .N is the number of upper crossing points.
14.2 Arrangement of optical wave observation records
(5)
14.2.1 Select 10 large waves from the 15 to 20 grid values of the observed waves, calculate their average value A, and select the largest grid value M, respectively calculate the tenth sky wave height and the maximum wave height, the formula is as follows: H/L=ABKH
H.. MBKH*
K = [H—(-d)B]-1
H=a-(h+c)
Where: a—
tenth sky wave height, m!
maximum wave height, m
—average of the number of grids of 10 large wave jumps!
Maximum wave runout grid value
Unit scale value of the wave height scale of the graticule:
Design height of the wave meter, m
During observation, the distance from the optical axis of the meter to the end of the buoy pole, m: the reading of the average position disk of the buoy pole end runout on the wave height scale; the center scale value of the wave height scale of the design wave meter, the distance from the optical axis of the meter to the tide height reference plane, m; the distance from the top of the buoy pole to the water surface, m;. (92
Wave height correction coefficient can also be found in the wave height correction table of the wave meter. When looking up the table, (d, + d)/2 in the table is replaced by 73. According to the requirements of Article 3, the sampling time interval is selected, and the wave height and period of no less than 100 waves are measured within the sampling time (1720min), and 100 of them are selected to obtain the characteristic values or record the wave surface simulation curve.
13.4.2.2 When using the wave surface simulation curve to record, the measurement date, time, paper feed speed and range should be noted. 13.4.2.3 When the wave height reaches the height required for magnetic recording as specified by the measuring station, the original wave sampling data shall be transferred to a medium (tape, floppy disk) and labeled.
13.4.3 Wave measurement method using an optical wave meter on the shore
13.4.3.1 Observe the top of the buoy pole that jumps with the waves, measure the time required for 10 consecutive waves to pass through the buoy, repeat the measurement 3 times (the time interval between two consecutive measurements should be less than 1 minute), and divide the sum of the 3 measured times by 30 as the average period. 13.4.3.2 When 15 to 20 large waves pass through the buoy within 100 times the average period, measure the number of grids of the wave height scale (take a decimal place) that the top of the buoy pole drops from the wave crest to the wave trough. Then observe a series of continuous waves (generally 15-20) passing through the buoy, the average position of the top of the buoy pole jumping is read on the wave height scale 7, take one decimal place, in order to reduce the error, the d value should be read as much as possible when the wave is small.
13.4.4 Monthly measurement method
13.4.4.1 Select a representative fixed point on the sea surface F, visually observe the time required for 10 continuous waves to pass through a fixed point, repeat the measurement three times, and take the average value as the average period. 13.4.4.2 In the time of 100 times the average period, pay close attention to a fixed point on the sea surface, and estimate the tenth-large wave height and the maximum wave height.
14 Arrangement of observation records
14.1 Arrangement of self-recording records
When arranging the self-recording records of sea waves, the passband uses the zero-crossing method to determine the wave height and period. 14.1.1 Principles of pre-processing of self-records
Determine the "zero line" of the record. When the "zero line" has obvious drift, it should be carried out in sections: a.
Obviously wrong data records (singular points) should be eliminated and then reasonably processed; determine the upper zero points of the surface record;
d. Select 100 continuous or quasi-continuous waves in the wave surface record. 14.1.2 Arrangement of sampling data records
After calculating the wave height and corresponding period of each wave of the 100 waves selected after pre-processing (the total number of waves is 100), arrange them from the highest to the lowest according to the height, and calculate the maximum wave height, maximum wave period, one-tenth of the large wave height, one-tenth of the large wave period, effective wave height, effective wave period, average wave height, and average period.
14.1.3 Arrangement of simulation curve records
14.1.3.1 Correction of cycle
If the paper feed speed of the simulation curve recording paper is inconsistent with the specified paper feed speed, the read cycle should be divided by the correction value of the recording paper feed speed.
14.1.3.2 Calculate the wave height and cycle by the measurement method. Measure the wave height and cycle of the simulation curve of 100 waves selected after pretreatment one by one. Calculate various wave height and cycle characteristics according to the requirements of Article 14.1.2.
14.1.3.3 Calculate the wave height and cycle a by the maximum value method. Among the 100 wave simulation curve records selected after preprocessing, calculate the time interval t between the first upper span zero point and the last working span peak point and the number of upper span zero points Nh. Find the highest peak, lowest trough, second highest peak and second lowest trough in the wave surface record, and measure their heights from the zero line (all positive values); use the formula to calculate the effective wave height:
Where: Hs-
GB/T 14914---94
[K,(HA +He) + K,(H +H))]
K, = 21/29-1/3(1 + 0. 2898-1 - 0. 2478-2)-1K. = 21/80-/3(1 - 0. 2118-1 -- 0. 1038-*)-1B- LnN
-effective wave height + m #
the quotient of the highest point of a wave surface to the zero line, He—the height of the lowest point of the wave surface to the zero line, m; Hs-the height of the second highest point of the wave surface to the zero line, m; Hu—the height of the second lowest point of the wave surface to the zero line, m! K1, K,..wave height correction coefficient,
6——the natural logarithm of the number of times of crossing zero point, N
-the number of times of crossing zero point.
In the wave surface simulation curve record, find the maximum wave height and directly measure the maximum wave height value to calculate the average period;
T=t/(N- 1)
In the formula,
average period; 83
&…-the time interval between the first upper crossing zero point to the last upper crossing zero point of this observation record, .N is the number of upper crossing points.
14.2 Arrangement of optical wave observation records
(5)
14.2.1 Select 10 large waves from the 15 to 20 grid values of the observed waves, calculate their average value A, and select the largest grid value M, respectively calculate the tenth sky wave height and the maximum wave height, the formula is as follows: H/L=ABKH
H.. MBKH*
K = [H—(-d)B]-1
H=a-(h+c)
Where: a—
tenth sky wave height, m!
maximum wave height, m
—average of the number of grids of 10 large wave jumps!
Maximum wave runout grid value
Unit scale value of the wave height scale of the graticule:
Design height of the wave meter, m
During observation, the distance from the optical axis of the meter to the end of the buoy pole, m: the reading of the average position disk of the buoy pole end runout on the wave height scale; the center scale value of the wave height scale of the design wave meter, the distance from the optical axis of the meter to the tide height reference plane, m; the distance from the top of the buoy pole to the water surface, m;. (92
Wave height correction coefficient can also be found in the wave height correction table of the wave meter. When looking up the table, (d, + d)/2 in the table is replaced by 73. According to the requirements of Article 3, the sampling time interval is selected, and the wave height and period of no less than 100 waves are measured within the sampling time (1720min), and 100 of them are selected to obtain the characteristic values or record the wave surface simulation curve.
13.4.2.2 When using the wave surface simulation curve to record, the measurement date, time, paper feed speed and range should be noted. 13.4.2.3 When the wave height reaches the height required for magnetic recording as specified by the measuring station, the original wave sampling data shall be transferred to a medium (tape, floppy disk) and labeled.
13.4.3 Wave measurement method using an optical wave meter on the shore
13.4.3.1 Observe the top of the buoy pole that jumps with the waves, measure the time required for 10 consecutive waves to pass through the buoy, repeat the measurement 3 times (the time interval between two consecutive measurements should be less than 1 minute), and divide the sum of the 3 measured times by 30 as the average period. 13.4.3.2 When 15 to 20 large waves pass through the buoy within 100 times the average period, measure the number of grids of the wave height scale (take a decimal place) that the top of the buoy pole drops from the wave crest to the wave trough. Then observe a series of continuous waves (generally 15-20) passing through the buoy, the average position of the top of the buoy pole jumping is read on the wave height scale 7, take one decimal place, in order to reduce the error, the d value should be read as much as possible when the wave is small.
13.4.4 Monthly measurement method
13.4.4.1 Select a representative fixed point on the sea surface F, visually observe the time required for 10 continuous waves to pass through a fixed point, repeat the measurement three times, and take the average value as the average period. 13.4.4.2 In the time of 100 times the average period, pay close attention to a fixed point on the sea surface, and estimate the tenth-large wave height and the maximum wave height.
14 Arrangement of observation records
14.1 Arrangement of self-recording records
When arranging the self-recording records of sea waves, the passband uses the zero-crossing method to determine the wave height and period. 14.1.1 Principles of pre-processing of self-records
Determine the "zero line" of the record. When the "zero line" has obvious drift, it should be carried out in sections: a.
Obviously wrong data records (singular points) should be eliminated and then reasonably processed; determine the upper zero points of the surface record;
d. Select 100 continuous or quasi-continuous waves in the wave surface record. 14.1.2 Arrangement of sampling data records
After calculating the wave height and corresponding period of each wave of the 100 waves selected after pre-processing (the total number of waves is 100), arrange them from the highest to the lowest according to the height, and calculate the maximum wave height, maximum wave period, one-tenth of the large wave height, one-tenth of the large wave period, effective wave height, effective wave period, average wave height, and average period.
14.1.3 Arrangement of simulation curve records
14.1.3.1 Correction of cycle
If the paper feed speed of the simulation curve recording paper is inconsistent with the specified paper feed speed, the read cycle should be divided by the correction value of the recording paper feed speed.
14.1.3.2 Calculate the wave height and cycle by the measurement method. Measure the wave height and cycle of the simulation curve of 100 waves selected after pretreatment one by one. Calculate various wave height and cycle characteristics according to the requirements of Article 14.1.2.
14.1.3.3 Calculate the wave height and cycle a by the maximum value method. Among the 100 wave simulation curve records selected after preprocessing, calculate the time interval t between the first upper span zero point and the last working span peak point and the number of upper span zero points Nh. Find the highest peak, lowest trough, second highest peak and second lowest trough in the wave surface record, and measure their heights from the zero line (all positive values); use the formula to calculate the effective wave height:
Where: Hs-
GB/T 14914---94
[K,(HA +He) + K,(H +H))]
K, = 21/29-1/3(1 + 0. 2898-1 - 0. 2478-2)-1K. = 21/80-/3(1 - 0. 2118-1 -- 0. 1038-*)-1B- LnN
-effective wave height + m #
the quotient of the highest point of a wave surface to the zero line, He—the height of the lowest point of the wave surface to the zero line, m; Hs-the height of the second highest point of the wave surface to the zero line, m; Hu—the height of the second lowest point of the wave surface to the zero line, m! K1, K,..wave height correction coefficient,
6——the natural logarithm of the number of times of crossing zero point, N
-the number of times of crossing zero point.
In the wave surface simulation curve record, find the maximum wave height and directly measure the maximum wave height value to calculate the average period;
T=t/(N- 1)
In the formula,
average period; 83
&…-the time interval between the first upper crossing zero point to the last upper crossing zero point of this observation record, .N is the number of upper crossing points.
14.2 Arrangement of optical wave observation records
(5)
14.2.1 Select 10 large waves from the 15 to 20 grid values of the observed waves, calculate their average value A, and select the largest grid value M, respectively calculate the tenth sky wave height and the maximum wave height, the formula is as follows: H/L=ABKH
H.. MBKH*
K = [H—(-d)B]-1
H=a-(h+c)
Where: a—
tenth sky wave height, m!
maximum wave height, m
—average of the number of grids of 10 large wave jumps!
Maximum wave runout grid value
Unit scale value of the wave height scale of the graticule:
Design height of the wave meter, m
During observation, the distance from the optical axis of the meter to the end of the buoy pole, m: the reading of the average position disk of the buoy pole end runout on the wave height scale; the center scale value of the wave height scale of the design wave meter, the distance from the optical axis of the meter to the tide height reference plane, m; the distance from the top of the buoy pole to the water surface, m;. (92
Wave height correction coefficient can also be found in the wave height correction table of the wave meter. When looking up the table, (d, + d)/2 in the table is replaced by 71 Correction of cycle
If the paper feed speed of the analog curve recording paper is inconsistent with the specified paper feed speed, the read cycle should be divided by the correction value of the recording paper feed speed.
14.1.3.2 Calculate the wave height and period by the measurement method. Measure the wave height and period of the simulation curve of 100 waves selected after preprocessing one by one. After the cycle, calculate the various wave height and period characteristic values according to the requirements of Article 14.1.2.
14.1.3.3 Calculate the wave height and period a by the maximum value method. Among the 100 wave simulation curve records selected after preprocessing, calculate the time interval t between the first upper span zero point and the last working span peak point and the number of upper span zero points Nh. Find the highest peak, lowest trough, second highest peak and second lowest trough in the wave surface record, and measure their heights from the zero line (all positive values); use the formula to calculate the effective wave height:
Where: Hs-
GB/T 14914---94
[K,(HA +He) + K,(H +H))]
K, = 21/29-1/3(1 + 0. 2898-1 - 0. 2478-2)-1K. = 21/80-/3(1 - 0. 2118-1 -- 0. 1038-*)-1B- LnN
-effective wave height + m #
the quotient of the highest point of a wave surface to the zero line, He—the height of the lowest point of the wave surface to the zero line, m; Hs-the height of the second highest point of the wave surface to the zero line, m; Hu—the height of the second lowest point of the wave surface to the zero line, m! K1, K,..wave height correction coefficient,
6——the natural logarithm of the number of times of crossing zero point, N
-the number of times of crossing zero point.
In the wave surface simulation curve record, find the maximum wave height and directly measure the maximum wave height value to calculate the average period;
T=t/(N- 1)
In the formula,
average period; 83
&…-the time interval between the first upper crossing zero point to the last upper crossing zero point of this observation record, .N is the number of upper crossing points.
14.2 Arrangement of optical wave observation records
(5)
14.2.1 Select 10 large waves from the 15 to 20 grid values of the observed waves, calculate their average value A, and select the largest grid value M, respectively calculate the tenth sky wave height and the maximum wave height, the formula is as follows: H/L=ABKH
H.. MBKH*
K = [H—(-d)B]-1
H=a-(h+c)
Where: a—
tenth sky wave height, m!
maximum wave height, m
—average of the number of grids of 10 large wave jumps!
Maximum wave runout grid value
Unit scale value of the wave height scale of the graticule:
Design height of the wave meter, m
During observation, the distance from the optical axis of the meter to the end of the buoy pole, m: the reading of the average position disk of the buoy pole end runout on the wave height scale; the center scale value of the wave height scale of the design wave meter, the distance from the optical axis of the meter to the tide height reference plane, m; the distance from the top of the buoy pole to the water surface, m;. (92
Wave height correction coefficient can also be found in the wave height correction table of the wave meter. When looking up the table, (d, + d)/2 in the table is replaced by 71 Correction of cycle
If the paper feed speed of the analog curve recording paper is inconsistent with the specified paper feed speed, the read cycle should be divided by the correction value of the recording paper feed speed.
14.1.3.2 Calculate the wave height and period by the measurement method. Measure the wave height and period of the simulation curve of 100 waves selected after preprocessing one by one. After the cycle, calculate the various wave height and period characteristic values according to the requirements of Article 14.1.2.
14.1.3.3 Calculate the wave height and period a by the maximum value method. Among the 100 wave simulation curve records selected after preprocessing, calculate the time interval t between the first upper span zero point and the last working span peak point and the number of upper span zero points Nh. Find the highest peak, lowest trough, second highest peak and second lowest trough in the wave surface record, and measure their heights from the zero line (all positive values); use the formula to calculate the effective wave height:
Where: Hs-
GB/T 14914---94
[K,(HA +He) + K,(H +H))]
K, = 21/29-1/3(1 + 0. 2898-1 - 0. 2478-2)-1K. = 21/80-/3(1 - 0. 2118-1 -- 0. 1038-*)-1B- LnN
-effective wave height + m #
the quotient of the highest point of a wave surface to the zero line, He—the height of the lowest point of the wave surface to the zero line, m; Hs-the height of the second highest point of the wave surface to the zero line, m; Hu—the height of the second lowest point of the wave surface to the zero line, m! K1, K,..wave height correction coefficient,
6——the natural logarithm of the number of times of crossing zero point, N
-the number of times of crossing zero point.
In the wave surface simulation curve record, find the maximum wave height and directly measure the maximum wave height value to calculate the average period;
T=t/(N- 1)
In the formula,
average period; 83
&…-the time interval between the first upper crossing zero point to the last upper crossing zero point of this observation record, .N is the number of upper crossing points.
14.2 Arrangement of optical wave observation records
(5)
14.2.1 Select 10 large waves from the 15 to 20 grid values of the observed waves, calculate their average value A, and select the largest grid value M, respectively calculate the tenth sky wave height and the maximum wave height, the formula is as follows: H/L=ABKH
H.. MBKH*
K = [H—(-d)B]-1
H=a-(h+c)
Where: a—
tenth sky wave height, m!
maximum wave height, m
—average of the number of grids of 10 large wave jumps!
Maximum wave runout grid value
Unit scale value of the wave height scale of the graticule:
Design height of the wave meter, m
During observation, the distance from the optical axis of the meter to the end of the buoy pole, m: the reading of the average position disk of the buoy pole end runout on the wave height scale; the center scale value of the wave height scale of the design wave meter, the distance from the optical axis of the meter to the tide height reference plane, m; the distance from the top of the buoy pole to the water surface, m;. (92
Wave height correction coefficient can also be found in the wave height correction table of the wave meter. When looking up the table, (d, + d)/2 in the table is replaced by 7
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