阅读说明：本技术 基于近偏移距地震信号的节点时钟漂移校正方法及装置 (Node clock drift correction method and device based on near offset seismic signals ) 是由 杜海涛 罗敏学 杨文渊 李阳 杨云涛 景月红 于 2019-02-27 设计创作，主要内容包括：本发明提供一种基于近偏移距地震信号的节点时钟漂移校正方法及装置,包括：设定地震观测系统中的炮点和节点的位置关系,使得近偏移距的炮点涵盖节点开始采集和节点结束采集的时间段内的炮点；根据位置关系和水深确定近偏移距范围,使得要获取的地震信号的初至波为直达波；利用水中声速对获取的近偏移距地震信号进行线性动校正获得近偏移距校正地震信号；将近偏移距校正地震信号初至波与T0时刻的地震信号进行比较确定时钟漂移量和时钟漂移模型；将近偏移距校正地震信号进行排序,利用时钟漂移模型对排序后的近偏移距校正地震信号进行时钟校正,获得校正后的地震信号。该方案可以准确地实现节点时钟漂移量校正。(The invention provides a node clock drift correction method and a node clock drift correction device based on a near offset seismic signal, wherein the method comprises the following steps: setting the position relation between the shot points and the nodes in the earthquake observation system, so that the shot points with the close offset range cover the shot points in the time period when the nodes start to collect and the nodes finish collecting; determining a near offset range according to the position relation and the water depth, so that the first-motion wave of the seismic signal to be acquired is a direct-arrival wave; carrying out linear dynamic correction on the acquired near offset seismic signal by using the sound velocity in water to obtain a near offset corrected seismic signal; comparing the first-motion wave of the near offset correction seismic signal with the seismic signal at the time of T0 to determine a clock drift amount and a clock drift model; and sequencing the near offset correction seismic signals, and performing clock correction on the sequenced near offset correction seismic signals by using a clock drift model to obtain corrected seismic signals. The scheme can accurately realize the correction of the node clock drift amount.)

1. A node clock drift correction method based on a near offset seismic signal is characterized by comprising the following steps:

setting the position relationship between the shot points and the nodes in the earthquake observation system, wherein the position relationship enables the shot points with the close offset to cover the shot points in the time period when the nodes start to collect and the nodes finish collecting;

determining a near offset range according to the position relation and the water depth, wherein the near offset range enables the first arrival wave of the seismic signal to be acquired to be a direct arrival wave;

acquiring a near offset seismic signal according to the near offset range;

performing linear dynamic correction on the near offset seismic signal by using the sound velocity in water to obtain a near offset correction seismic signal;

comparing the near offset correction seismic signal first arrival wave with the seismic signal at the time of T0, and determining the clock drift amount according to the comparison result;

determining a clock drift model according to the clock drift amount;

sequencing the near offset correction seismic signals to obtain sequenced near offset correction seismic signals;

and performing clock correction on the sequenced near offset correction seismic signals by using the clock drift model to obtain corrected seismic signals.

2. The method for correcting node clock drift based on near offset seismic signals according to claim 1, wherein the positional relationship between the shot and the node in the seismic observation system is set as follows:

taking the node as a center, and enabling the shot point to be located in a rectangular range with a preset length;

or, the shot point is positioned in the circular range with the preset radius by taking the node as the circle center.

3. The method of near-offset seismic signal-based node clock drift correction of claim 1, wherein a clock drift model is determined from the amount of clock drift as follows:

analyzing the clock drift amount to obtain the variation trend of the clock drift amount;

and determining a clock drift model according to the change trend of the clock drift amount.

4. The method of near-offset seismic signal-based node clock drift correction of claim 1, further comprising:

comparing the corrected seismic signal first arrival wave with the seismic signal at the time of T0, and if the corrected seismic signal first arrival wave is consistent with the seismic signal at the time of T0, determining that the clock drift model is correctly selected; and if the corrected seismic signal first-motion wave is inconsistent with the seismic signal at the time T0, determining that the clock drift model is selected incorrectly, and re-determining the clock drift model according to the obtained clock drift amount.

5. A node clock drift correction apparatus based on near offset seismic signals, comprising:

the position relation setting module is used for setting the position relation between the shot points and the nodes in the earthquake observation system, and the position relation enables the shot points with the close offset to cover the shot points in the time period when the nodes start to collect and the nodes finish to collect;

a near offset range determining module, configured to determine a near offset range according to the position relationship and the water depth, where the near offset range enables a first-arrival wave of the seismic signal to be acquired to be a direct-arrival wave;

the near offset seismic signal acquisition module is used for acquiring a near offset seismic signal according to the near offset range;

the linear dynamic correction module is used for carrying out linear dynamic correction on the near offset seismic signal by utilizing the sound velocity in water to obtain a near offset correction seismic signal;

the clock drift amount determining module is used for comparing the near offset correction seismic signal first arrival wave with the seismic signal at the time of T0 and determining the clock drift amount according to the comparison result;

the clock drift model determining module is used for determining a clock drift model according to the clock drift amount;

a sorting module for sorting the near offset correction seismic signals to obtain sorted near offset correction seismic signals;

and the clock correction module is used for performing clock correction on the sequenced near offset correction seismic signals by using the clock drift model to obtain corrected seismic signals.

6. The near-offset seismic signal-based node clock drift correction device of claim 5, wherein the positional relationship setting module is specifically configured to:

setting the position relation of the shot points and the nodes in the seismic observation system according to the following modes:

taking the node as a center, and enabling the shot point to be located in a rectangular range with a preset length;

or, the shot point is positioned in the circular range with the preset radius by taking the node as the circle center.

7. The near-offset seismic signal-based node clock drift correction apparatus of claim 5, wherein the clock drift model determination module is specifically configured to;

determining a clock drift model according to the obtained clock drift amount according to the following modes:

analyzing the clock drift amount to obtain the variation trend of the clock drift amount;

and determining a clock drift model according to the change trend of the clock drift amount.

8. The near-offset seismic signal-based node clock drift correction apparatus of claim 5, further comprising: the clock drift model verification module is used for comparing the corrected seismic signal first arrival wave with the seismic signal at the time of T0, and if the corrected seismic signal first arrival wave is consistent with the seismic signal at the time of T0, determining that the clock drift model is correctly selected; and if the corrected seismic signal first-motion wave is inconsistent with the seismic signal at the time T0, determining that the clock drift model is selected incorrectly, and re-determining the clock drift model according to the obtained clock drift amount.

9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the computer program implements the method for node clock drift correction based on near-offset seismic signals of any of claims 1 to 4.

10. A computer-readable storage medium storing a computer program for executing the method for correcting node clock drift based on a near offset seismic signal according to any one of claims 1 to 4.

Technical Field

The invention relates to the technical field of node clock quality control, in particular to a node clock drift correction method and device based on a near offset seismic signal.

Background

In the seismic exploration data acquisition of an Ocean Bottom Node (OBN is called an Ocean Bottom Node, which is a multi-component seismograph which is positioned on the Ocean Bottom and can independently acquire and record seismic signals), each Node (namely a wave detection point) is an independently operated data acquisition unit after being started, and no external monitoring equipment is connected in a wired or wireless mode, so that compared with the traditional land and Ocean towline wired or wireless remote sensing equipment, the Node equipment lacks a GPS synchronous signal for real-time service of a clock, and cannot perform synchronous correction of the clock in real time. Clock drift exists in each node device after the collection is completed, and generally, the clock drift amount of the node device continuously collects data underwater for 20 days is less than 6ms, so that the clock drift amount is firstly corrected after the node data downloading is completed. However, node equipment has just emerged in the geophysical prospecting industry, and many people do not know that node clock drift exists in the node equipment, so that a node clock drift correction method is urgently needed to be established to accurately correct the clock drift.

Disclosure of Invention

The embodiment of the invention provides a node clock drift correction method and device based on a near offset seismic signal, which can accurately correct clock drift.

The embodiment of the invention provides a node clock drift correction method based on a near offset seismic signal, which comprises the following steps:

setting the position relationship between the shot points and the nodes in the earthquake observation system, wherein the position relationship enables the shot points with the close offset to cover the shot points in the time period when the nodes start to collect and the nodes finish collecting;

determining a near offset range according to the position relation and the water depth, wherein the near offset range enables the first arrival wave of the seismic signal to be acquired to be a direct arrival wave;

acquiring a near offset seismic signal according to the near offset range;

performing linear dynamic correction on the near offset seismic signal by using the sound velocity in water to obtain a near offset correction seismic signal;

comparing the near offset correction seismic signal first arrival wave with the seismic signal at the time of T0, and determining the clock drift amount according to the comparison result;

determining a clock drift model according to the clock drift amount;

sequencing the near offset correction seismic signals to obtain sequenced near offset correction seismic signals;

and performing clock correction on the sequenced near offset correction seismic signals by using the clock drift model to obtain corrected seismic signals.

The embodiment of the invention also provides a node clock drift correction device based on the near offset seismic signal, which comprises:

the position relation setting module is used for setting the position relation between the shot points and the nodes in the earthquake observation system, and the position relation enables the shot points with the close offset to cover the shot points in the time period when the nodes start to collect and the nodes finish to collect;

a near offset range determining module, configured to determine a near offset range according to the position relationship and the water depth, where the near offset range enables a first-arrival wave of the seismic signal to be acquired to be a direct-arrival wave;

the near offset seismic signal acquisition module is used for acquiring a near offset seismic signal according to the near offset range;

the linear dynamic correction module is used for carrying out linear dynamic correction on the near offset seismic signal by utilizing the sound velocity in water to obtain a near offset correction seismic signal;

the clock drift amount determining module is used for comparing the near offset correction seismic signal first arrival wave with the seismic signal at the time of T0 and determining the clock drift amount according to the comparison result;

the clock drift model determining module is used for determining a clock drift model according to the clock drift amount;

a sorting module for sorting the near offset correction seismic signals to obtain sorted near offset correction seismic signals;

and the clock correction module is used for performing clock correction on the sequenced near offset correction seismic signals by using the clock drift model to obtain corrected seismic signals.

The embodiment of the invention also provides computer equipment which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein when the processor executes the computer program, the node clock drift correction method based on the near offset distance seismic signals is realized.

The embodiment of the invention also provides a computer readable storage medium, which stores a computer program for executing the node clock drift correction method based on the near offset distance seismic signal.

In the embodiment of the invention, the position relationship between a shot point and a node in a seismic observation system is set in advance, so that the shot point with the near offset covers the shot point in the time period when the node starts to collect and finishes collecting, the near offset range is determined according to the position relationship and the water depth, the first arrival wave of the seismic signal to be acquired is a direct arrival wave, and the seismic signal with the near offset is acquired according to the near offset range; performing linear dynamic correction on the near offset seismic signal by using the sound velocity in water to obtain a near offset correction seismic signal; comparing the near offset correction seismic signal first arrival wave with the seismic signal at the time of T0, and determining the clock drift amount according to the comparison result; determining a clock drift model according to the clock drift amount; sequencing the near offset correction seismic signals to obtain sequenced near offset correction seismic signals; and performing clock correction on the sequenced near offset correction seismic signals by using the clock drift model to obtain corrected seismic signals, so that the clock drift amount can be accurately corrected, the correctness of data time of each shot after segmentation is ensured, and the method is of great importance to the subsequent quality control and processing of nodes.

Drawings

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

FIG. 1 is a flow chart of a method for correcting node clock drift based on a near offset seismic signal according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a linear clock drift model according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a quadratic clock drift model according to an embodiment of the present invention;

FIG. 4 is a flow chart of a method for correcting node clock drift based on a near offset seismic signal according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a nodal close-offset seismic signal volume provided by an embodiment of the present invention;

FIG. 6 is a graphical illustration of a result of linear dynamic correction of a seismic signal prior to clock correction for a selected near offset range, in accordance with an embodiment of the present invention;

FIG. 7 is a graphical illustration of a linear motion correction result of a seismic signal after clock correction in a selected near offset range, in accordance with an embodiment of the present invention;

FIG. 8 is a block diagram of a node clock drift correction apparatus based on a near offset seismic signal according to an embodiment of the present invention;

fig. 9 is a structural block diagram of a node clock drift correction device based on a near offset seismic signal according to an embodiment of the present invention (ii).

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.