阅读说明：本技术 一种确定深海压力仪海深测量精度的方法及系统 (Method and system for determining sea depth measurement precision of deep sea pressure instrument ) 是由 管斌 孙中苗 翟振和 刘晓刚 段渭超 于 2019-10-21 设计创作，主要内容包括：本发明公开一种确定深海压力仪海深测量精度的方法及系统。该方法包括：获取深海压力仪的布设位置；获取测高卫星与深海压力仪同步观测期间的卫星轨道数据和深海压力仪在测高卫星过顶时间的海深测量数据；根据卫星轨道数据和深海压力仪的布设位置,获取海面高差；根据卫星轨道数据,获得点PCA处卫星测量海面高值；根据深海压力仪在测高卫星过顶时间的海深测量数据,采用差值计算,获取卫星测量海面高值对应时刻的深海压力仪的海深测量值；获得深海压力仪的测量标准差,得到深海压力仪进行海深测量时的精度。本发明可以实现深海压力仪相对海深测量精度的评估,且评估结果可靠性高。(The invention discloses a method and a system for determining the sea depth measurement precision of a deep sea pressure instrument. The method comprises the following steps: acquiring the layout position of the deep sea pressure gauge; acquiring satellite orbit data of a height measurement satellite and a deep sea pressure instrument during synchronous observation and sea depth measurement data of the deep sea pressure instrument in the overhead time of the height measurement satellite; acquiring sea level altitude difference according to the satellite orbit data and the arrangement position of the deep sea pressure gauge; obtaining a satellite measurement sea level height value at a PCA (principal component analysis) point according to the satellite orbit data; according to the sea depth measurement data of the deep sea pressure instrument in the overhead time of the height measurement satellite, obtaining the sea depth measurement value of the deep sea pressure instrument at the moment corresponding to the sea surface height value measured by the satellite by adopting difference value calculation; and obtaining the measurement standard deviation of the deep sea pressure instrument and the precision of the deep sea pressure instrument in the process of measuring the depth of the sea. The invention can realize the evaluation of the deep sea pressure instrument relative to the measurement precision of the deep sea depth, and the reliability of the evaluation result is high.)

1. a method for determining the sea depth measurement accuracy of a deep sea pressure gauge is characterized by comprising the following steps:

acquiring the layout position of the deep sea pressure gauge;

Acquiring satellite orbit data of a height measurement satellite and the deep sea pressure instrument during synchronous observation and sea depth measurement data of the deep sea pressure instrument in the over-top time of the height measurement satellite;

Acquiring sea level altitude difference according to the satellite orbit data and the arrangement position of the deep sea pressure gauge; the sea level elevation difference is the sea level elevation difference between a sea level point CP corresponding to the arrangement position of the deep sea pressure instrument and a PCA closest to the CP in the satellite ground track;

According to the satellite orbit data, calculating by adopting a difference value to obtain a sea level height value measured by a satellite at a point PCA;

According to the sea depth measurement data of the deep sea pressure gauge in the overhead time of the altimetry satellite, obtaining the sea depth measurement value of the deep sea pressure gauge at the moment corresponding to the sea surface height value measured by the satellite;

and obtaining the measurement standard deviation of the deep sea pressure instrument according to the sea level height difference, the satellite measurement sea level height value at the PCA point and the sea depth measurement value of the deep sea pressure instrument, and obtaining the precision of the deep sea pressure instrument in the sea depth measurement.

2. The method of determining the sea depth measurement accuracy of a deep sea manometer of claim 1, wherein the satellite orbit data during the simultaneous observation of the altimetry satellite and the deep sea manometer comprises the orbit altitude of the satellite, the ranging value of the altimeter from the satellite to the sea surface, dry tropospheric delay correction data, wet tropospheric delay correction data, ionospheric delay correction data, loaded tidal correction data, earth solid tidal correction data, extreme tidal correction data, and sea state bias correction data.

3. the method for determining the sea depth measurement accuracy of the deep sea pressure gauge according to claim 1, wherein the obtaining of the sea level difference according to the satellite orbit data and the layout position of the deep sea pressure gauge specifically comprises:

calculating the distance between a sea surface point CP and a point PCA according to the satellite orbit data and the arrangement position of the deep sea pressure gauge;

Calculating the average sea level height gradient value of the CP by adopting a global average sea level height model;

According to the distance between the sea surface point CP and the point PCA and the average sea surface height gradient value of the point CP, a formula delta MSS (maximum Grad) is utilized_MSSdetermining the sea level height difference by x l; wherein Δ MSS is sea level altitude difference, Grad_MSSis the average sea level height gradient value for point CP and l is the distance between sea level point CP and point PCA.

4. The method for determining the sea depth measurement accuracy of the deep sea pressure gauge according to claim 2, wherein the obtaining of the sea level height measured by the satellite at the point PCA by using the difference calculation according to the satellite orbit data specifically comprises:

using SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) Calculating to obtain a satellite measurement sea level height value at the PCA point; wherein, SSH_satMeasuring sea level height for a satellite at a point PCA, h being the orbital height of the satellite, R being the range from the satellite to a altimeter at the sea level, R_dryRepresenting dry tropospheric delay correction data, R_wetrepresenting wet tropospheric delay correction data, R_ionoData representing ionospheric delay correction, R_ltRepresenting load tide correction data, R_stRepresenting earth's solid tidal correction data, R_ptindicating tidal correction data, R_ssbindicating sea state deviation correction data.

5. The method for determining the sea depth measurement accuracy of the deep sea pressure gauge according to claim 1, wherein the obtaining of the standard deviation of the deep sea pressure gauge from the sea level difference, the satellite measurement sea level value at the point PCA and the sea depth measurement value of the deep sea pressure gauge to obtain the accuracy of the deep sea pressure gauge in sea depth measurement specifically comprises:

According to the sea level difference and the sea depth measurement value of the deep sea pressure instrument, a formula SSH is utilized_sat1＝D+d_mooring+ delta MSS calculates the sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the PCA point; wherein, SSH_sat1Measuring sea level height value for a deep sea pressure instrument at the same time as measuring sea level height value for the satellite at the point PCA, D is zero height of the deep sea pressure instrument, D is zero height of the deep sea pressure instrument_mooringThe sea depth measurement value of the deep sea pressure instrument is shown, and delta MSS is the sea level height difference;

According to the sea level height measured by the deep sea pressure instrument and the sea level height measured by the satellite at the point PCA, a formula is utilizedcalculating an observation difference value in a single synchronous observation period; wherein the content of the first and second substances,for observed differences during a single simultaneous observation, SSH_sat2Measuring sea level height values for the satellites at the point PCA;

Obtaining a sequence standard difference value according to the change sequence of the observation difference values in a plurality of synchronous observation periods;

acquiring a precision value of the height measurement satellite for measuring the sea level height;

Measuring the sea level height precision value according to the sea level height difference, the sequence standard difference value and the height measurement satellite by using a formulaCalculating the measurement standard deviation of the deep sea pressure instrument to obtain the precision of the deep sea pressure instrument in the process of measuring the depth of the sea; wherein the content of the first and second substances,Is the standard deviation of the deep sea pressure instrument,Is the standard deviation value of the sequence,Measuring sea level height accuracy value, sigma, for altimetry satellites_ΔMSSStandard deviation of sea level height difference.

6. A system for determining the accuracy of a deep sea pressure gauge sea depth measurement, comprising:

The laying position acquisition module is used for acquiring the laying position of the deep sea pressure gauge;

the observation data acquisition module is used for acquiring satellite orbit data during synchronous observation of a height measurement satellite and the deep sea pressure instrument and deep sea measurement data of the deep sea pressure instrument in the overhead time of the height measurement satellite;

The sea level altitude difference acquisition module is used for acquiring sea level altitude difference according to the satellite orbit data and the arrangement position of the deep sea pressure gauge; the sea level elevation difference is the sea level elevation difference between a sea level point CP corresponding to the arrangement position of the deep sea pressure instrument and a PCA closest to the CP in the satellite ground track;

The satellite measurement sea level height value acquisition module is used for acquiring a satellite measurement sea level height value at a PCA (principal component analysis) point by adopting difference calculation according to the satellite orbit data;

The sea depth measurement value acquisition module of the deep sea pressure instrument is used for acquiring the sea depth measurement value of the deep sea pressure instrument at the moment corresponding to the sea surface measurement value of the satellite according to the sea depth measurement data of the deep sea pressure instrument in the overhead time of the altitude measurement satellite;

And the measurement standard deviation acquisition module is used for acquiring the measurement standard deviation of the deep sea pressure instrument according to the sea level height difference, the satellite measurement sea level height value at the point PCA and the sea depth measurement value of the deep sea pressure instrument, and acquiring the precision of the deep sea pressure instrument in sea depth measurement.

7. the system for determining the sea depth measurement accuracy of deep sea stressometers according to claim 6, wherein the observation data acquisition module acquires satellite orbit data during synchronous observation of the altimetric satellite and the deep sea stressometers, including the orbit height of the satellite, the ranging value of the altimeter from the satellite to the sea surface, dry tropospheric delay correction data, wet tropospheric delay correction data, ionospheric delay correction data, load tide correction data, earth solid tide correction data, extreme tide correction data, and sea state deviation correction data.

8. The system for determining the sea depth measurement accuracy of deep sea pressure gauges according to claim 6, wherein the sea level difference acquisition module comprises:

The distance calculation unit is used for calculating the distance between the sea surface point CP and the point PCA according to the satellite orbit data and the arrangement position of the deep sea pressure gauge;

The average sea surface height gradient value calculating unit is used for calculating the average sea surface height gradient value of the CP by adopting a global average sea surface height model;

A sea level height difference determining unit for determining the average sea level height gradient value of the point CP according to the distance between the sea level point CP and the point PCA and the formula delta MSS Grad_MSSdetermining the sea level height difference by x l; wherein Δ MSS is sea level altitude difference, Grad_MSSIs the average sea level height gradient value for point CP and l is the distance between sea level point CP and point PCA.

9. The system for determining the accuracy of deep sea barometer sea depth measurements of claim 7, wherein the satellite measured sea level height acquisition module utilizes SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) Calculating to obtain a satellite measurement sea level height value at the PCA point; wherein, SSH_satmeasuring sea level height for a satellite at a point PCA, h being the orbital height of the satellite, R being the range from the satellite to a altimeter at the sea level, R_dryRepresenting dry tropospheric delay correction data, R_wetrepresenting wet tropospheric delay correction data, R_ionodata representing ionospheric delay correction, R_ltRepresenting load tide correction data, R_strepresenting earth solidsTidal correction data, R_ptindicating tidal correction data, R_ssbIndicating sea state deviation correction data.

10. The system for determining the sea depth measurement accuracy of deep sea pressure gauges according to claim 6, wherein the measurement standard deviation obtaining module comprises:

a calculation unit for measuring sea surface height value of the deep sea pressure instrument, which is used for utilizing a formula SSH according to the sea surface height difference and the sea depth measurement value of the deep sea pressure instrument_sat1＝D+d_mooring+ delta MSS calculates the sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the PCA point; wherein, SSH_sat1Measuring sea level height value for a deep sea pressure instrument at the same time as measuring sea level height value for the satellite at the point PCA, D is zero height of the deep sea pressure instrument, D is zero height of the deep sea pressure instrument_mooringThe sea depth measurement value of the deep sea pressure instrument is shown, and delta MSS is the sea level height difference;

an observation difference value calculation unit for calculating the sea level height value according to the sea level height value measured by the deep sea pressure instrument and the sea level height value measured by the satellite at the point PCA by using a formulacalculating an observation difference value in a single synchronous observation period; wherein the content of the first and second substances,For observed differences during a single simultaneous observation, SSH_sat2Measuring sea level height values for the satellites at the point PCA;

a sequence standard deviation value obtaining unit, configured to obtain a sequence standard deviation value according to a change sequence of the observation deviation values in the multiple synchronous observation periods;

The height measurement satellite height measurement accuracy value acquisition unit is used for acquiring an accuracy value of the height measurement satellite for measuring the sea level height;

A deep sea pressure instrument measurement standard deviation obtaining unit for measuring the sea level height precision value according to the sea level height difference, the sequence standard deviation value and the height measurement satellite by using a formulacalculating the measurement standard deviation of the deep sea pressure instrument to obtain the precision of the deep sea pressure instrument in the process of measuring the depth of the sea; wherein the content of the first and second substances,Is the standard deviation of the deep sea pressure instrument,Is the standard deviation value of the sequence,Measuring sea level height accuracy value, sigma, for altimetry satellites_ΔMSSstandard deviation of sea level height difference.

Technical Field

The invention relates to the field of marine surveying and mapping, in particular to a method and a system for determining the sea depth measurement precision of a deep sea pressure instrument.

Background

along with the continuous improvement of the cognitive demand of human beings on the accuracy of the deep blue sea, high-precision wide-range sea depth measuring equipment is produced. In recent years, the performance of sea depth measuring equipment is further improved, and the measuring resolution reaches millimeter level when the sea depth of thousands of meters is observed. However, the accuracy assessment of sea depth measuring devices has long lacked an effective means. This mainly involves two reasons: on one hand, the measuring precision of the pressure instrument for monitoring the deep sea and sea depth change is difficult to evaluate through simulating an experimental environment; on the other hand, for a wide-range deep sea depth measuring apparatus, it is difficult to find a high-precision deep sea depth reference value for measurement precision evaluation thereof.

Therefore, it is very important to find a method for evaluating the high-quality precision of a pressure gauge (called deep sea pressure gauge for short) arranged on the deep sea bottom.

Disclosure of Invention

the invention aims to provide a method and a system for determining the sea depth measurement precision of a deep sea pressure instrument, which are used for determining the relative sea depth measurement precision of the deep sea pressure instrument by using the data of a marine height measurement satellite so as to realize the evaluation of the relative sea depth measurement precision of the deep sea pressure instrument.

In order to achieve the purpose, the invention provides the following scheme:

a method of determining the accuracy of a deep sea pressure gauge sea depth measurement, comprising:

acquiring the layout position of the deep sea pressure gauge;

Acquiring satellite orbit data of a height measurement satellite and the deep sea pressure instrument during synchronous observation and sea depth measurement data of the deep sea pressure instrument in the over-top time of the height measurement satellite;

acquiring sea level altitude difference according to the satellite orbit data and the arrangement position of the deep sea pressure gauge; the sea level elevation difference is the sea level elevation difference between a sea level point CP corresponding to the arrangement position of the deep sea pressure instrument and a PCA closest to the CP in the satellite ground track;

According to the satellite orbit data, calculating by adopting a difference value to obtain a sea level height value measured by a satellite at a point PCA;

according to the sea depth measurement data of the deep sea pressure gauge in the overhead time of the altimetry satellite, obtaining the sea depth measurement value of the deep sea pressure gauge at the moment corresponding to the sea surface height value measured by the satellite;

And obtaining the measurement standard deviation of the deep sea pressure instrument according to the sea level height difference, the satellite measurement sea level height value at the PCA point and the sea depth measurement value of the deep sea pressure instrument, and obtaining the precision of the deep sea pressure instrument in the sea depth measurement.

Optionally, the satellite orbit data during the synchronous observation of the height measurement satellite and the deep sea pressure gauge comprises the orbit height of the satellite, the distance measurement value of an altimeter from the satellite to the sea surface, dry troposphere delay correction data, wet troposphere delay correction data, ionosphere delay correction data, load tide correction data, earth solid tide correction data, extreme tide correction data and sea state deviation correction data.

Optionally, the obtaining sea height difference according to the satellite orbit data and the layout position of the deep sea pressure gauge specifically includes:

Calculating the distance between a sea surface point CP and a point PCA according to the satellite orbit data and the arrangement position of the deep sea pressure gauge;

Calculating the average sea level height gradient value of the CP by adopting a global average sea level height model;

According to the distance between the sea surface point CP and the point PCA and the average sea surface height gradient value of the point CP, a formula delta MSS (maximum Grad) is utilized_MSSDetermining the sea level height difference by x l; wherein Δ MSS is sea level altitude difference, Grad_MSSis the average sea level height gradient value for point CP and l is the distance between sea level point CP and point PCA.

optionally, the obtaining a sea height value measured by a satellite at a point PCA according to the satellite orbit data by using difference calculation specifically includes:

using SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) Calculating to obtain a satellite measurement sea level height value at the PCA point; wherein, SSH_satMeasuring sea level height for a satellite at a point PCA, h being the orbital height of the satellite, R being the range from the satellite to a altimeter at the sea level, R_dryRepresenting dry tropospheric delay correction data, R_wetRepresenting wet tropospheric delay correction data, R_ionodata representing ionospheric delay correction, R_ltRepresenting load tide correction data, R_stRepresenting earth's solid tidal correction data, R_ptIndicating tidal correction data, R_ssbIndicating sea state deviation correction data.

Optionally, the obtaining a measurement standard deviation of the deep sea pressure gauge according to the sea level height difference, the satellite measurement sea level height value at the point PCA and the sea depth measurement value of the deep sea pressure gauge to obtain the precision of the deep sea pressure gauge in sea depth measurement specifically includes:

According to the sea level difference and the sea depth measurement value of the deep sea pressure instrument, a formula SSH is utilized_sat1＝D+d_mooring+ delta MSS calculates the sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the PCA point; wherein, SSH_sat1Measuring sea level height value for a deep sea pressure instrument at the same time as measuring sea level height value for the satellite at the point PCA, D is zero height of the deep sea pressure instrument, D is zero height of the deep sea pressure instrument_mooringThe sea depth measurement value of the deep sea pressure instrument is shown, and delta MSS is the sea level height difference;

According to the sea level height measured by the deep sea pressure instrument and the sea level height measured by the satellite at the point PCA, a formula is utilizedcalculating an observation difference value in a single synchronous observation period; wherein the content of the first and second substances,For observed differences during a single simultaneous observation, SSH_sat2Measuring sea level height values for the satellites at the point PCA;

obtaining a sequence standard difference value according to the change sequence of the observation difference values in a plurality of synchronous observation periods;

Acquiring a precision value of the height measurement satellite for measuring the sea level height;

Measuring the sea level height precision value according to the sea level height difference, the sequence standard difference value and the height measurement satellite by using a formulaCalculating the measurement standard deviation of the deep sea pressure instrument to obtain the precision of the deep sea pressure instrument in the process of measuring the depth of the sea; wherein the content of the first and second substances,Is the standard deviation of the deep sea pressure instrument,is the standard deviation value of the sequence,Measuring sea level height accuracy value, sigma, for altimetry satellites_ΔMSSStandard deviation of sea level height difference.

The invention also provides a system for determining the sea depth measurement accuracy of the deep sea pressure instrument, which comprises:

The laying position acquisition module is used for acquiring the laying position of the deep sea pressure gauge;

The observation data acquisition module is used for acquiring satellite orbit data during synchronous observation of a height measurement satellite and the deep sea pressure instrument and deep sea measurement data of the deep sea pressure instrument in the overhead time of the height measurement satellite;

The sea level altitude difference acquisition module is used for acquiring sea level altitude difference according to the satellite orbit data and the arrangement position of the deep sea pressure gauge; the sea level elevation difference is the sea level elevation difference between a sea level point CP corresponding to the arrangement position of the deep sea pressure instrument and a PCA closest to the CP in the satellite ground track;

The satellite measurement sea level height value acquisition module is used for acquiring a satellite measurement sea level height value at a PCA (principal component analysis) point by adopting difference calculation according to the satellite orbit data;

The sea depth measurement value acquisition module of the deep sea pressure instrument is used for acquiring the sea depth measurement value of the deep sea pressure instrument at the moment corresponding to the sea surface measurement value of the satellite according to the sea depth measurement data of the deep sea pressure instrument in the overhead time of the altitude measurement satellite;

And the measurement standard deviation acquisition module is used for acquiring the measurement standard deviation of the deep sea pressure instrument according to the sea level height difference, the satellite measurement sea level height value at the point PCA and the sea depth measurement value of the deep sea pressure instrument, and acquiring the precision of the deep sea pressure instrument in sea depth measurement.

Optionally, the satellite orbit data during the synchronous observation of the altimetric satellite and the deep sea pressure gauge, which is acquired by the observation data acquisition module, includes the orbit height of the satellite, the distance measurement value of the altimeter from the satellite to the sea surface, dry troposphere delay correction data, wet troposphere delay correction data, ionosphere delay correction data, load tide correction data, earth solid tide correction data, extreme tide correction data, and sea state deviation correction data.

Optionally, the sea level difference obtaining module specifically includes:

The distance calculation unit is used for calculating the distance between the sea surface point CP and the point PCA according to the satellite orbit data and the arrangement position of the deep sea pressure gauge;

The average sea surface height gradient value calculating unit is used for calculating the average sea surface height gradient value of the CP by adopting a global average sea surface height model;

a sea level height difference determining unit for determining the average sea level height gradient value of the point CP according to the distance between the sea level point CP and the point PCA and the formula delta MSS Grad_MSSDetermining the sea level height difference by x l; wherein Δ MSS is sea level altitude difference, Grad_MSSIs the average sea level height gradient value for point CP and l is the distance between sea level point CP and point PCA.

Optionally, the module for obtaining sea level height measured by the satellite uses SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) Calculating to obtain a satellite measurement sea level height value at the PCA point; wherein, SSH_satmeasuring sea level height for a satellite at a point PCA, h being the orbital height of the satellite, R being the range from the satellite to a altimeter at the sea level, R_dryRepresenting dry tropospheric delay correction data, R_wetRepresenting wet tropospheric delay correction data, R_ionoData representing ionospheric delay correction, R_ltrepresenting load tide correction data, R_stRepresenting earth's solid tidal correction data, R_ptIndicating tidal correction data, R_ssbindicating sea state deviation correction data.

Optionally, the measurement standard deviation obtaining module specifically includes:

a calculation unit for measuring sea surface height value of the deep sea pressure instrument, which is used for utilizing a formula SSH according to the sea surface height difference and the sea depth measurement value of the deep sea pressure instrument_sat1＝D+d_mooring+ delta MSS calculates the sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the PCA point; wherein, SSH_sat1measuring sea level height value for a deep sea pressure instrument at the same time as measuring sea level height value for the satellite at the point PCA, D is zero height of the deep sea pressure instrument, D is zero height of the deep sea pressure instrument_mooringThe sea depth measurement value of the deep sea pressure instrument is shown, and delta MSS is the sea level height difference;

An observation difference value calculating unit for measuring sea level height value according to the deep sea pressure instrument and the satellite at the point PCA by using a formula delta-SSH_sat2-SSH_sat1Calculating an observation difference value in a single synchronous observation period; wherein the content of the first and second substances,for observed differences during a single simultaneous observation, SSH_sat2Measuring sea level height values for the satellites at the point PCA;

A sequence standard deviation value obtaining unit, configured to obtain a sequence standard deviation value according to a change sequence of the observation deviation values in the multiple synchronous observation periods;

The height measurement satellite height measurement accuracy value acquisition unit is used for acquiring an accuracy value of the height measurement satellite for measuring the sea level height;

A deep sea pressure instrument measurement standard deviation obtaining unit for measuring the sea level height precision value according to the sea level height difference, the sequence standard deviation value and the height measurement satellite by using a formulaCalculating the measurement standard deviation of the deep sea pressure instrument to obtain the precision of the deep sea pressure instrument in the process of measuring the depth of the sea; wherein the content of the first and second substances,Is the standard deviation of the deep sea pressure instrument,is the standard deviation value of the sequence,Measuring sea level height accuracy value, sigma, for altimetry satellites_ΔMSSstandard deviation of sea level height difference.

according to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the invention uses the high-precision height measurement satellite data to evaluate the precision of the deep sea pressure instrument for measuring the relative change of the sea depth, and provides a feasible way for evaluating the measurement precision of the pressure instrument in the deep sea environment; the high-precision sea surface high observation characteristic of the satellite height measurement technology in the deep sea area is fully utilized, and the precision evaluation result has high reliability; the method is simple in principle and simple and convenient to calculate, and can be used as a tool for performing performance test on the deep sea pressure instrument by a third party.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a schematic flow chart of a method for determining the sea depth measurement accuracy of a deep sea pressure gauge according to the present invention;

FIG. 2 is a schematic structural diagram of a system for determining the sea depth measurement accuracy of a deep sea pressure gauge according to the present invention;

FIG. 3 is a schematic diagram of a system according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the relationship between the CP and the position of the satellite constellation point trajectory in accordance with an embodiment of the present invention;

FIG. 5 is a schematic diagram of a positional relationship between a survey station and a ground track in an embodiment of the present invention;

Fig. 6 is a sequence diagram of the observed difference value according to the embodiment of the present invention.

Detailed Description

the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a method and a system for determining the sea depth measurement precision of a deep sea pressure instrument, which utilize the characteristic advantages of a height measurement satellite on the high-precision measurement of the sea surface and use the observed value as a reference value for evaluating the deep sea pressure instrument, thereby evaluating the measurement precision of the deep sea pressure instrument on the relative sea depth, providing a measurement index of the deep sea pressure instrument in a specific sea depth and using the measurement index as a third-party evaluation means of the measurement performance of the deep sea pressure instrument.

in order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

FIG. 1 is a schematic flow chart of the method for determining the sea depth measurement accuracy of the deep sea pressure gauge according to the present invention. As shown in fig. 1, the method for determining the sea depth measurement accuracy of the deep sea pressure gauge comprises the following steps:

Step 100: and acquiring the layout position of the deep sea pressure gauge.

Step 200: and acquiring satellite orbit data during synchronous observation of the height measuring satellite and the deep sea pressure gauge and sea depth measurement data of the deep sea pressure gauge in the overhead time of the height measuring satellite.

according to the determined height measuring satellite, satellite orbit data of a plurality of periods during synchronous observation can be directly obtained, wherein the satellite orbit data comprises the orbit height of the satellite, the distance measurement value of an altimeter from the satellite to the sea surface, dry troposphere delay correction data, wet troposphere delay correction data, ionosphere delay correction data, load tide correction data, earth solid tide correction data, extreme tide correction data and sea state deviation correction data. And the sea depth measurement data of the deep sea pressure instrument in the satellite over-top time can be obtained.

Step 300: and acquiring sea level altitude difference according to the satellite orbit data and the arrangement position of the deep sea pressure gauge. The sea level height difference is the sea level height difference between a sea level point CP corresponding to the arrangement position of the deep sea pressure gauge and a point PCA closest to the point CP in the satellite ground track. The specific process is as follows:

firstly, the position of the point PCA can be obtained according to the satellite orbit data and the coordinates of the layout position of the pressure instrument, and the distance l between the sea surface point CP and the point PCA can be calculated.

Then, calculating the average sea level height gradient value Grad of the point CP by adopting a global average sea level height model according to the coordinates of the layout position of the pressure gauge_MSS。

Finally, the formula Δ MSS ═ Grad is used_MSSX l determines the sea level difference Δ MSS.

Step 400: and calculating by adopting a difference value according to the satellite orbit data to obtain a sea level height value measured by the satellite at the point PCA. Specifically, the satellite orbit data is obtained by interpolation calculation in the calculation process according to the error change characteristic, the interpolation calculation method is shown in table 1, and a specific value of the satellite orbit data when the satellite reaches the PCA can be obtained by the interpolation calculation method.

TABLE 1 fitting interpolation method for different parameter items

Parameter item	Fitting interpolation method
		Ionosphere	Averaging TCA-21s to +20s
dry troposphere	Linear fitting of TCA-5s to +5 s; interpolation at TCA time
		wet troposphere	Linear fit between TCA-15s to +15 s; interpolation at TCA time
Deviation from sea state	Fitting a ternary polynomial from TCA-10s to +10 s; interpolation at TCA time
		Ku band range finding value	a fifth order polynomial fit between TCA-20s to +19 s; interpolation at TCA time
High orbit of satellite	Fitting a cubic polynomial between TCA-20s and +19 s; interpolation at TCA time
		Measured value of deep sea pressure gauge	Linear fitting TCA-1100s to +1100 s; interpolation at TCA time

Then, using the formula SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) Calculating to obtain a satellite measurement sea level height value at the PCA point; wherein, SSH_satMeasuring sea level height for a satellite at a point PCA, h being the orbital height of the satellite, R being the range from the satellite to a altimeter at the sea level, R_dryIndicating dry convectionLayer delay corrected data, R_wetRepresenting wet tropospheric delay correction data, R_ionoData representing ionospheric delay correction, R_ltRepresenting load tide correction data, R_stRepresenting earth's solid tidal correction data, R_ptindicating tidal correction data, R_ssbIndicating sea state deviation correction data.

step 500: and acquiring the sea depth measurement value of the deep sea pressure gauge at the moment corresponding to the sea surface height value measured by the satellite according to the sea depth measurement data of the deep sea pressure gauge in the satellite over-top time.

And defining the time of the satellite reaching the point PCA as TCA, and screening to obtain the sea depth measurement value of the deep sea pressure instrument corresponding to the TCA time according to the sea depth measurement data of the deep sea pressure instrument in the overhead time of the altitude measurement satellite, namely the sea depth measurement value of the deep sea pressure instrument corresponding to the sea surface height measured by the satellite at the point PCA.

Step 600: and obtaining a measurement standard deviation of the deep sea pressure instrument according to the sea level height difference, the sea level height value measured by the satellite at the point PCA and the sea depth measurement value of the deep sea pressure instrument, and obtaining the precision of the deep sea pressure instrument in measuring the sea depth. The specific process is as follows:

Step 1: according to the sea level difference and the sea depth measurement value of the deep sea pressure instrument, a formula SSH is utilized_sat1＝D+d_mooring+ delta MSS calculates the sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the PCA point; wherein, SSH_sat1Measuring sea level height value for a deep sea pressure instrument at the same time as measuring sea level height value for the satellite at the point PCA, D is zero height of the deep sea pressure instrument, D is zero height of the deep sea pressure instrument_mooringAnd the delta MSS is the sea level height difference.

step 2: according to the sea level height measured by the deep sea pressure instrument and the sea level height measured by the satellite at the point PCA, a formula is utilizedCalculating an observation difference value in a single synchronous observation period; wherein the content of the first and second substances,for observed differences during a single simultaneous observation, SSH_sat2Sea level height values are measured for the satellites at the point PCA. According to the formula of Step1, the method can obtain

step 3: obtaining a sequence standard deviation value according to the change sequence of the observation deviation values in a plurality of synchronous observation periods

Step 4: and acquiring the precision value of the height measurement satellite for measuring the sea level height. The parameter is related to the adopted height measurement satellite, and the height measurement satellite can obtain high-precision sea surface measurement through checking and reading according to the adopted height measurement satellite

step 5: measuring the sea level height precision value according to the sea level height difference, the sequence standard difference value and the height measurement satellite by using a formulaCalculating the measurement standard deviation of the deep sea pressure instrument to obtain the precision of the deep sea pressure instrument in the process of measuring the depth of the sea; wherein the content of the first and second substances,Is the standard deviation of the deep sea pressure instrument,is the standard deviation value of the sequence,Measuring sea level height accuracy value, sigma, for altimetry satellites_ΔMSSStandard deviation of sea level height difference.

Formula (II)Corresponding error propagation equation isSince D is constant at zero tidal frame, there is σ_Dis 0, so thatTherefore, the temperature of the molten metal is controlled,

corresponding to the method for determining the sea depth measurement accuracy of the deep sea pressure instrument shown in fig. 1, the invention also provides a system for determining the sea depth measurement accuracy of the deep sea pressure instrument, and fig. 2 is a schematic structural diagram of the system for determining the sea depth measurement accuracy of the deep sea pressure instrument. As shown in fig. 2, the system for measuring the sea depth precision of the deep sea pressure gauge comprises the following structures:

and a layout position acquisition module 201, configured to acquire a layout position of the deep sea pressure gauge.

The observation data acquisition module 202 is used for acquiring satellite orbit data during synchronous observation of the altimeter satellite and the deep sea pressure instrument and deep sea measurement data of the deep sea pressure instrument during the overhead time of the altimeter satellite.

A sea level altitude difference obtaining module 203, configured to obtain a sea level altitude difference according to the satellite orbit data and the layout position of the deep sea pressure gauge; the sea level height difference is the sea level height difference between a sea level point CP corresponding to the arrangement position of the deep sea pressure gauge and a point PCA closest to the point CP in the satellite ground track.

and the satellite measurement sea level height value acquisition module 204 is used for acquiring a satellite measurement sea level height value at the PCA position by adopting difference calculation according to the satellite orbit data.

the sea depth measurement value acquisition module 205 of the deep sea pressure gauge is configured to acquire the sea depth measurement value of the deep sea pressure gauge at a time corresponding to the sea surface measurement value of the satellite according to the sea depth measurement data of the deep sea pressure gauge at the time when the altitude measurement satellite passes the top.

And the measurement standard deviation acquisition module 206 is configured to obtain a measurement standard deviation of the deep sea pressure gauge according to the sea level height difference, the satellite measurement sea level height value at the point PCA and the sea depth measurement value of the deep sea pressure gauge, so as to obtain the precision of the deep sea pressure gauge in sea depth measurement.

as another embodiment, the satellite orbit data during the synchronous observation of the altimetric satellite and the deep sea pressure gauge, which is acquired by the observation data acquisition module 202 of the present invention, includes the orbit height of the satellite, the ranging value of the altimeter from the satellite to the sea surface, the dry troposphere delay correction data, the wet troposphere delay correction data, the ionosphere delay correction data, the loaded tide correction data, the earth solid tide correction data, the extreme tide correction data, and the sea state deviation correction data.

As another embodiment, the sea level difference obtaining module 203 of the present invention specifically includes:

And the distance calculation unit is used for calculating the distance between the sea surface point CP and the point PCA according to the satellite orbit data and the arrangement position of the deep sea pressure gauge.

and the average sea surface height gradient value calculating unit is used for calculating the average sea surface height gradient value of the point CP by adopting the global average sea surface height model.

A sea level height difference determining unit for determining the average sea level height gradient value of the point CP according to the distance between the sea level point CP and the point PCA and the formula delta MSS Grad_MSSdetermining the sea level height difference by x l; wherein Δ MSS is sea level altitude difference, Grad_MSSIs the average sea level height gradient value for point CP and l is the distance between sea level point CP and point PCA.

as another embodiment, the module 204 for acquiring sea level height measured by the satellite of the present invention utilizes SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) Calculating to obtain a satellite measurement sea level height value at the PCA point; wherein, SSH_satMeasuring sea level height for a satellite at a point PCA, h being the orbital height of the satellite, R being the range from the satellite to a altimeter at the sea level, R_dryrepresenting dry tropospheric delay correction data, R_wetIndicating wet tropospheric delayCorrection of data, R_ionoData representing ionospheric delay correction, R_ltRepresenting load tide correction data, R_stRepresenting earth's solid tidal correction data, R_ptindicating tidal correction data, R_ssbIndicating sea state deviation correction data.

As another embodiment, the measurement standard deviation obtaining module 206 of the present invention specifically includes:

A calculation unit for measuring sea surface height value of the deep sea pressure instrument, which is used for utilizing a formula SSH according to the sea surface height difference and the sea depth measurement value of the deep sea pressure instrument_sat1＝D+d_mooring+ delta MSS calculates the sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the PCA point; wherein, SSH_sat1Measuring sea level height value for a deep sea pressure instrument at the same time as measuring sea level height value for the satellite at the point PCA, D is zero height of the deep sea pressure instrument, D is zero height of the deep sea pressure instrument_mooringand the delta MSS is the sea level height difference.

An observation difference value calculation unit for calculating the sea level height value according to the sea level height value measured by the deep sea pressure instrument and the sea level height value measured by the satellite at the point PCA by using a formulaCalculating an observation difference value in a single synchronous observation period; wherein the content of the first and second substances,for observed differences during a single simultaneous observation, SSH_sat2Sea level height values are measured for the satellites at the point PCA.

And the sequence standard difference value acquisition unit is used for obtaining the sequence standard difference value according to the change sequence of the observation difference values in the synchronous observation periods.

And the height measurement satellite height measurement accuracy value acquisition unit is used for acquiring the accuracy value of the height measurement satellite for measuring the sea level height.

A deep sea pressure instrument measurement standard deviation obtaining unit for measuring the sea level height precision value according to the sea level height difference, the sequence standard deviation value and the height measurement satelliteby the formulacalculating the measurement standard deviation of the deep sea pressure instrument to obtain the precision of the deep sea pressure instrument in the process of measuring the depth of the sea; wherein the content of the first and second substances,is the standard deviation of the deep sea pressure instrument,is the standard deviation value of the sequence,measuring sea level height accuracy value, sigma, for altimetry satellites_ΔMSSstandard deviation of sea level height difference.

The following provides a specific embodiment to further illustrate the technical solution of the present invention shown in fig. 1 and 2.

Fig. 3 is a schematic diagram of a system structure in an embodiment of the present invention, and as shown in fig. 3, the present embodiment uses a satellite altimeter technology to measure an instantaneous sea level height SSH of a satellite through an altimeter mounted on the satellite, assisted by a precise orbit determination technology, and then performs propagation delay correction and sea state deviation effect correction of an electromagnetic signal of the altimeter. The depth change measured by the pressure gauge is the difference between the instantaneous sea level height and the zero level height of the pressure gauge. The zero elevation of the pressure gauge cannot be measured accurately and directly, and can be considered as a constant value under a zero tidal frame.

The instantaneous sea level height is usually not completely coincident with the sea level position (marked as point CP) corresponding to the pressure gauge, the point Closest to the arrangement position of the pressure gauge in the satellite ground track is a PCA (Point of close approach) point, the position relationship of the points is shown in FIG. 4, FIG. 4 is a schematic diagram of the relationship between the point CP and the satellite subsatellite point track position in the specific implementation case of the invention, wherein T is the satellite ground track running direction. The time corresponding to the point PCA is denoted as TCA (time of ClosestApproach).

the actual sea level difference between the point PCA and the point CP is the instantaneous sea level differenceΔ SSH, the instantaneous Sea level difference can be approximated by using the difference between the average Sea level heights (MSS), which is denoted as Δ MSS_PCA-MSS_CP. Δ MSS may pass through the average sea level high gradient Grad of point CP_MSSAnd the product of the distance l between the PCA and the CP is obtained as follows:

ΔMSS＝MSS_PCA-MSS_DART＝Grad_MSS×l (1)

Wherein, Grad_MSSMay be found by a global average sea height model (e.g., CNES _ CLS 15).

In FIG. 4, the y-axis is aligned with the north, and the angle between the normal of the trajectory and the positive y-axis is θ ([ - π, π]) Positive clockwise about the origin on the y-axis. Firstly, the average sea level height of a point CP in the global average sea level height model and adjacent grid points is used for calculating the gradient Grad of the average sea level height of the point CP in the east-west direction_xAnd north-south average sea level high gradient Grad_yThen, Grad can be obtained according to the formula (2)_MSS。

Grad_MSS＝Grad_xsinθ+Grad_ycosθ (2)

The sea level height value measured by the deep sea pressure instrument at the same time as the sea level height value measured by the satellite at the point PCA is as follows:

SSH_sat1＝D+d_mooring+ΔMSS (3)

SSH in zero tidal conditions_sat2Can be calculated from equation (4), i.e.:

SSH_sat2＝h-(R+R_dry+R_wet+R_iono+R_ssb+R_lt+R_st+R_pt) (4)

Wherein h is the orbital altitude of the satellite, R is the ranging value of the altimeter from the satellite to the sea surface, R_dryrepresenting dry tropospheric delay correction data, R_wetRepresenting wet tropospheric delay correction data, R_ionoData representing ionospheric delay correction, R_ltrepresenting load tide correction data, R_stRepresenting earth's solid tidal correction data, R_ptIndicating tidal correction data, R_ssbindicating sea state deviation correction data.

in the specific implementation case, the deep sea pressure gauge is arranged on the seabed of thousands of meters, and the calculation result of the invention is given by taking data of synchronous observation of a Jason-3 height measurement satellite and a DART station to an adjacent sea area as an example. 21419A DART survey station is deployed at a depth of about 5.3km in the sea, the distance between the deployed position and the theoretical ground track of the Jason-3 satellite is less than 1km, the position relationship between the two is shown in FIG. 5, FIG. 5 is a schematic diagram of the position relationship between the survey station and the ground track in the embodiment of the present invention, and the DART survey station is a Parasitic Digiquartz 410K pressure sensor. The specific process is as follows:

The method comprises the following steps: according to the observation data of No. 21419 DART survey station, the survey station arranges a coordinate position (44.435 degrees N, 155.717 degrees E) between 2016, 2, 23 and 2017, 7, 3, and obtains a gradient Grad value of the normal average sea level height of the satellite trajectory at the arrangement point of the region through the calculation of three global average sea level height models of DTU13, CNES _ CLS15 and WHU2013 according to the coordinate position (44.435 degrees N, 155.717 degrees E)_MSSis-1.43 cm/km east west.

Taking synchronous observation data of the 3 rd period of the Jason-3 satellite as an example, the steps from the second step to the fifth step are as follows:

step two: acquiring change values (30 s before and after TCA) of front and back nine parameters of a satellite overpressure instrument according to a GDR data product of a Jason-3 satellite; and acquiring the measured sea depth change value of the pressure instrument 1h before and after the TCA according to the satellite over-top time.

Step three: obtaining the position of the PCA point as (44.4396 degrees N,155.7065 degrees E), wherein the distance between the PCA point and the sea surface point corresponding to the pressure instrument is 0.98 km; calculating the average sea level height gradient Grad according to the step one_MSSAnd the delta MSS between the two points is calculated to be-1.4 cm (the PCA point is 1.4cm higher than the sea surface of the pressure instrument point).

Step four: according to the table 1, the PCA point at the TCA moment is obtained to measure the sea height SSH_satis 10.8234m, d_mooring10.9594m (assuming D is a constant 5336.586 m);

Step five: according to the formulaObserved difference during single synchronous observationIs-12.2 cm;

the difference sequence is obtained by repeating the second step to the fifth step according to the results of 51 times synchronous observation of the Jason-3 satellite and the 21419 DART pressure gauge during the period from 2016, 23 and 2017, 7, 3, and fig. 6 is a sequence diagram of the change of the observed difference in the embodiment of the present invention.

Step six: calculating to obtain the standard deviation of the difference sequenceis 10.78 cm;

step seven: consult the Jason-3 satellite user manual, the satellite sea level high measurement accuracyis 3.53cm, sigma_ΔMSSSet to 0.3 cm. Obtaining the standard deviation of the pressure gauge by calculationThe sea depth measuring precision is 10.18cm, namely the sea depth relative measuring precision of a deep sea pressure gauge used by a DART measuring station No. 21419 is 10.18 cm.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.