CN111551952A - Extraction method of water depth measurement laser data, water depth measurement method and device - Google Patents

Extraction method of water depth measurement laser data, water depth measurement method and device Download PDF

Info

Publication number
CN111551952A
CN111551952A CN202010380093.0A CN202010380093A CN111551952A CN 111551952 A CN111551952 A CN 111551952A CN 202010380093 A CN202010380093 A CN 202010380093A CN 111551952 A CN111551952 A CN 111551952A
Authority
CN
China
Prior art keywords
sequence
reverse
peak
standard deviation
determining
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010380093.0A
Other languages
Chinese (zh)
Other versions
CN111551952B (en
Inventor
谌一夫
乐源
陈伟涛
董玉森
吴临
王力哲
陈云亮
陈小岛
邓泽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China University of Geosciences
Original Assignee
China University of Geosciences
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China University of Geosciences filed Critical China University of Geosciences
Priority to CN202010380093.0A priority Critical patent/CN111551952B/en
Publication of CN111551952A publication Critical patent/CN111551952A/en
Application granted granted Critical
Publication of CN111551952B publication Critical patent/CN111551952B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/487—Extracting wanted echo signals, e.g. pulse detection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/491—Details of non-pulse systems
    • G01S7/493—Extracting wanted echo signals
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/30—Assessment of water resources

Abstract

The invention provides a method for extracting water depth measurement laser data, a water depth measurement method and a device, which relate to the technical field of laser depth measurement and comprise the following steps: acquiring pulse waveform data of the bathymetric laser, and determining a plurality of local extreme points of the pulse waveform data; determining a forward peak sequence, a forward valley sequence, a reverse peak sequence and a reverse valley sequence according to the plurality of local extreme points, wherein the forward direction of the pulse waveform data along the time coordinate axis is taken as the forward direction, and the reverse direction of the pulse waveform data along the time coordinate axis is taken as the reverse direction; determining an effective left boundary of the pulse waveform data according to the forward peak sequence and the forward valley sequence; determining an effective right boundary of the pulse waveform data according to the reverse peak sequence and the reverse valley sequence; pulse waveform data between the effective left boundary and the effective right boundary is extracted as effective data. The invention can improve the processing efficiency and the accuracy of the extraction of the effective data of the waveform by matching the wave crest sequence and the wave trough sequence.

Description

Extraction method of water depth measurement laser data, water depth measurement method and device
Technical Field
The invention relates to the technical field of laser sounding, in particular to a method for extracting water depth measurement laser data, a water depth measurement method and a water depth measurement device.
Background
With the development of the ocean mapping technology, the laser radar depth measurement technology is used as an important branch of the laser radar, is rapidly developed in recent years, and plays an important role in the fields of shallow sea area measurement, river channel water depth measurement, underwater topography and landform mapping and the like. The existing laser radar for measuring the depth of water belongs to an active optical depth measuring system, and the depth of the sea bottom is measured by emitting a high-power narrow-pulse laser beam. The system can be mounted on various platforms, and therefore has the advantages of high mobility and high efficiency. The laser radar for measuring the water depth is the only remote sensing depth measuring method which can meet the drawing precision requirement of IHO (International sea channel surveying organization) except for an acoustic method at present.
At present, most of the laser radars for water depth measurement are clear water bodies with good water quality around the island reef in the south China sea, and the water surface and water bottom waveform data structures of the water bodies are clear, so that the water bodies are easy to process. However, for relatively turbid water bodies such as the yellow sea or the Bohai sea, a large amount of waveform data of the water surface and the water bottom are easily overlapped, and the data overlapping degree in an ultra-shallow region is greatly increased until the limit of the laser physical time resolution is reached. The existing method for processing the laser radar data of the water body has the problem of low extraction precision of effective data, and influences the accuracy of water depth measurement.
Disclosure of Invention
To achieve the above objective and in order to solve at least some technical problems in the related art, an embodiment of a first aspect of the present invention provides a method for extracting bathymetry laser data, including:
acquiring pulse waveform data of a bathymetric laser, and determining a plurality of local extreme points of the pulse waveform data;
determining a forward peak sequence, a forward valley sequence, a reverse peak sequence and a reverse valley sequence according to the plurality of local extreme points, wherein the forward direction of the pulse waveform data along the time coordinate axis is taken as the forward direction, and the reverse direction of the pulse waveform data along the time coordinate axis is taken as the reverse direction;
determining an effective left boundary of the pulse waveform data according to the forward peak sequence and the forward valley sequence;
determining an effective right boundary of the pulse waveform data according to the reverse peak sequence and the reverse valley sequence;
extracting the pulse waveform data between the effective left boundary and the effective right boundary as effective data.
Further, in the forward peak sequence, the forward valley sequence, the reverse peak sequence and the reverse valley sequence determined according to the plurality of local extreme points, a local maximum point in the plurality of local extreme points is determined as a peak, and a local minimum point in the plurality of local extreme points is determined as a valley.
Further, the determining a forward peak sequence, a forward valley sequence, a reverse peak sequence and a reverse valley sequence according to the plurality of local extreme points includes: determining the forward peak sequence according to the plurality of local maximum points along the forward direction, determining the forward valley sequence according to the plurality of local minimum points along the forward direction, determining the reverse peak sequence according to the plurality of local maximum points along the reverse direction, and determining the reverse valley sequence according to the plurality of local minimum points along the reverse direction.
Further, the determining the valid left boundary of the pulse waveform data according to the forward peak sequence and the forward valley sequence comprises:
determining a forward cumulative standard deviation sequence of the forward peak sequence along the forward direction;
and determining the effective left boundary according to the forward cumulative standard deviation sequence and the forward trough sequence.
Further, the determining the forward cumulative standard deviation sequence of the forward peak sequence along the forward direction includes: and sequentially adding a peak from the first peak of the forward peak sequence along the forward direction, and determining the accumulated standard deviation corresponding to each peak to form the forward accumulated standard deviation sequence.
Further, the determining the effective left boundary according to the forward cumulative standard deviation sequence and the forward trough sequence comprises:
when one accumulated standard deviation in the forward accumulated standard deviation sequence is larger than or equal to a first multiple of the accumulated standard deviation determined last time, determining two time points corresponding to two wave crests corresponding to the accumulated standard deviation and the accumulated standard deviation determined last time;
determining a time point corresponding to a trough between the two time points according to the forward trough sequence;
and determining the time point corresponding to the trough as the effective left boundary.
Further, the determining a valid right boundary of the pulse waveform data from the reverse peak sequence and the reverse trough sequence comprises:
when the number of sampling points of the bathymetric survey laser is less than or equal to a preset threshold value, determining a reverse accumulated standard deviation sequence of the reverse peak sequence along the reverse direction;
and determining the effective right boundary according to the reverse cumulative standard deviation sequence and the reverse valley sequence.
Further, the determining a reverse cumulative standard deviation sequence of the reverse peak sequence along the reverse direction comprises: and sequentially adding a peak from the first peak of the reverse peak sequence along the reverse direction, and determining the accumulated standard deviation corresponding to each peak to form the reverse accumulated standard deviation sequence.
Further, the determining the valid right boundary according to the reverse cumulative standard deviation sequence and the reverse trough sequence comprises:
when one accumulated standard deviation in the reverse accumulated standard deviation sequence is larger than or equal to a second multiple of the accumulated standard deviation determined last time, determining two time points corresponding to two wave crests corresponding to the accumulated standard deviation and the accumulated standard deviation determined last time;
determining a time point corresponding to a trough between the two time points according to the reverse trough sequence;
and determining the time point corresponding to the trough as the effective right boundary.
Further, the determining a valid right boundary of the pulse waveform data from the reverse peak sequence and the reverse trough sequence comprises:
when the number of sampling points of the bathymetric survey laser is larger than a preset threshold value, determining the mean value of a peak accumulated standard deviation sequence and a trough accumulated standard deviation sequence from the initial moment to the effective left boundary of the pulse waveform data along the forward direction, and respectively determining a reverse peak accumulated standard deviation sequence of the reverse peak sequence and a reverse trough accumulated standard deviation sequence of the reverse trough sequence along the reverse direction;
and determining the effective right boundary according to the mean value, the reverse peak accumulated standard deviation sequence, the reverse valley accumulated standard deviation sequence and the reverse valley sequence.
Further, the determining the mean of the peak cumulative standard deviation sequence and the trough cumulative standard deviation sequence of the pulse waveform data from the initial time to the effective left boundary along the forward direction includes:
sequentially increasing a peak from the first peak of the forward peak sequence to the effective left boundary along the forward direction, and determining the accumulated standard deviation corresponding to each peak to form the peak accumulated standard deviation sequence;
sequentially increasing a trough from the first trough of the forward trough sequence to the effective left boundary along the forward direction, and determining the accumulated standard deviation corresponding to each trough to form the trough accumulated standard deviation sequence;
and determining the mean value of the peak accumulated standard deviation sequence and the trough accumulated standard deviation sequence.
Further, the determining the reverse peak cumulative standard deviation sequence of the reverse peak sequence and the reverse valley cumulative standard deviation sequence of the reverse valley sequence along the reverse direction respectively includes: sequentially adding a peak from the first peak of the reverse peak sequence along the reverse direction, and determining the accumulated standard deviation corresponding to each peak to form the reverse peak accumulated standard deviation sequence; and sequentially increasing a trough from the first trough of the reverse trough sequence along the reverse direction, and determining the accumulated standard deviation corresponding to each trough to form the reverse trough accumulated standard deviation sequence.
Further, determining the valid right boundary according to the mean, the reverse peak cumulative standard deviation sequence, the reverse valley cumulative standard deviation sequence, and the reverse valley sequence comprises:
when the average value of the accumulated standard deviations is larger than or equal to a third multiple of the average value, determining a time point corresponding to the corresponding peak according to the reverse peak sequence, wherein the average value of the accumulated standard deviations is the average value of one peak accumulated standard deviation in the reverse peak accumulated standard deviation sequence and one trough accumulated standard deviation in the reverse trough accumulated standard deviation sequence;
determining a time point corresponding to a trough adjacent to the peak along the forward direction according to the reverse trough sequence;
and determining the time point corresponding to the trough as the effective right boundary.
To achieve the above object, an embodiment of the second aspect of the present invention further provides an extraction apparatus for bathymetry laser data, including:
the acquisition module is used for acquiring pulse waveform data of the water depth measuring laser and determining a plurality of local extreme points of the pulse waveform data;
the processing module is used for determining a forward peak sequence, a forward valley sequence, a reverse peak sequence and a reverse valley sequence according to the local extreme points, wherein the forward direction of the pulse waveform data along a time coordinate axis is taken as the forward direction, and the reverse direction of the pulse waveform data along the time coordinate axis is taken as the reverse direction; further configured to determine an effective left boundary of the pulse waveform data from the forward peak sequence and the forward valley sequence; further configured to determine a valid right boundary of the pulse waveform data from the reverse peak sequence and the reverse valley sequence;
an extraction module to extract the pulse waveform data between the effective left boundary and the effective right boundary as effective data.
By using the method or the device for extracting the water depth measurement laser data, the accuracy of extracting the waveform effective data can be improved by extracting the local extreme points in the original pulse waveform, reconstructing the forward and reverse wave crest sequence and wave trough sequence according to a plurality of local extreme points, matching the wave crest sequence with the wave trough sequence and extracting the waveform effective left boundary and the waveform effective right boundary according to the corresponding accumulated standard deviation. In addition, the invention does not need to calculate and judge all sampling points, thereby effectively improving the efficiency of the system for processing the waveform. The invention can also count out system errors, can avoid mixing of useless waveform data containing system and random errors in subsequent processing, and effectively improves the success rate and precision of waveform data calculation.
To achieve the above object, an embodiment of a third aspect of the present invention provides a water depth measuring method, including:
obtaining effective data of a bathymetric laser waveform, wherein the effective data is obtained by adopting the above extraction method of the bathymetric laser data;
and determining the water depth of the measured area according to the effective data.
To achieve the above object, an embodiment of a fourth aspect of the present invention provides a water depth measuring apparatus, including:
the acquisition module is used for acquiring effective data of the bathymetric laser waveform, and the effective data is acquired by adopting the above extraction method of the bathymetric laser data;
and the measuring module is used for determining the water depth of the measured area according to the effective data.
By using the method or the device for water depth measurement, the original pulse waveform data is preprocessed by using an effective waveform extraction mode, so that the extraction of the effective range of the waveform signal can be effectively improved, and the accuracy and the processing efficiency of the water depth measurement are improved. And a large amount of environmental noise and system errors can be avoided, and the resolving success rate and precision of the system are improved.
To achieve the above object, an embodiment of a fifth aspect of the present invention provides a non-transitory computer-readable storage medium on which a computer program is stored, which, when executed by a processor, implements the method for extracting bathymetric laser data according to the first aspect of the present invention or implements the bathymetric method according to the third aspect of the present invention.
To achieve the above object, an embodiment of a sixth aspect of the present invention provides a computing device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor implements the method for extracting bathymetric laser data according to the first aspect of the present invention or implements the bathymetric method according to the third aspect of the present invention when executing the program.
The non-transitory computer-readable storage medium and the computing apparatus according to the present invention have similar advantageous effects to the method for extracting bathymetry laser data according to the first aspect of the present invention or to the method for bathymetry according to the third aspect of the present invention, and will not be described in detail herein.
Drawings
FIG. 1 is a schematic flow chart of a method for extracting bathymetric laser data according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of raw laser waveform data for one pulse in accordance with an embodiment of the present invention;
FIG. 3 is a diagram illustrating the determination of a plurality of sequences based on local extremum points according to an embodiment of the present invention;
FIG. 4 is a flowchart illustrating a method for determining a valid left boundary of pulse shape data according to an embodiment of the present invention;
FIG. 5 is a schematic flow chart illustrating the determination of an effective left boundary according to a forward cumulative standard deviation sequence and a forward trough sequence according to an embodiment of the present invention;
FIG. 6 is a flowchart illustrating a process for determining a valid right boundary of pulse shape data according to an embodiment of the present invention;
FIG. 7 is a flowchart illustrating the determination of an effective right boundary according to an inverse cumulative standard deviation sequence and an inverse valley sequence according to an embodiment of the present invention;
FIG. 8 is a second flowchart illustrating a process for determining a valid right boundary of pulse shape data according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of a laser pulse waveform with a large number of sample points according to an embodiment of the present invention;
FIG. 10 is a flowchart illustrating a process of determining a mean of a sequence of accumulated standard deviations, according to an embodiment of the present invention;
FIG. 11 is a schematic flow chart illustrating the determination of an effective right boundary based on a mean, an inverse peak cumulative standard deviation sequence, an inverse valley cumulative standard deviation sequence, and an inverse valley sequence in accordance with embodiments of the present invention;
FIG. 12 is a schematic diagram of an apparatus for extracting bathymetric laser data according to an embodiment of the present invention;
FIG. 13 is a schematic flow diagram of a water depth measurement method according to an embodiment of the present invention;
FIG. 14 is a schematic structural diagram of a bathymetric survey apparatus according to an embodiment of the present invention;
FIG. 15 is a schematic diagram of a computing device according to an embodiment of the invention.
Detailed Description
Embodiments in accordance with the present invention will now be described in detail with reference to the drawings, wherein like reference numerals refer to the same or similar elements throughout the different views unless otherwise specified. It is to be noted that the embodiments described in the following exemplary embodiments do not represent all embodiments of the present invention. They are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the claims, and the scope of the present disclosure is not limited in these respects. Features of the various embodiments of the invention may be combined with each other without departing from the scope of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
The acquisition of the submarine topography is one of the core contents of ocean basic mapping, and has very important significance for economic construction, ocean equity maintenance, national defense and scientific construction. In recent years, the laser radar depth measurement technology is rapidly developed and gradually replaces the traditional water depth measurement method to be widely applied to the field of ocean mapping.
However, echo pulse signals acquired by the existing water depth measurement laser radar have a large amount of noise, and particularly the measurement of relatively turbid water bodies and water bodies in extremely shallow regions belongs to the difficulty in the field. Because in the echo signal of this kind of water, surface echo and bottom echo can produce certain overlap, when the water is more muddy, the bottom echo signal still can be confused with other noises because the energy is less strong, and it is more difficult to extract.
By selecting the effective boundary of the laser data, the invention can effectively extract and de-noise the single-beam or multi-beam bathymetric measurement laser aiming at the echo signals under different water qualities, water depths and water body environments, thereby realizing automatic, rapid and efficient effective waveform data extraction and de-noising and improving the accuracy of bathymetry.
Fig. 1 is a schematic flowchart of a method for extracting bathymetric laser data according to an embodiment of the present invention, including steps S1 to S5.
In step S1, one pulse waveform data of the bathymetric laser is acquired, and a plurality of local extreme points of the pulse waveform data are determined. FIG. 2 is a diagram of raw laser waveform data for one pulse according to an embodiment of the present invention, wherein the axis of abscissa represents the time axis and the axis of ordinate represents the amplitude of the echo signal. In the embodiment of the invention, after the original waveform data of one pulse is acquired, a plurality of local extreme points along the time coordinate axis are determined according to the first derivative. And respectively determining a local maximum point and a local minimum point in the local extreme points through the direction change of the first derivative.
In step S2, a forward peak sequence, a forward valley sequence, a reverse peak sequence, and a reverse valley sequence are determined according to the plurality of local extreme points, where the forward direction of the pulse waveform data along the time coordinate axis is the forward direction, and the reverse direction of the pulse waveform data along the time coordinate axis is the reverse direction. In the embodiment of the present invention, a local maximum point in the plurality of local maximum points is determined as a peak, and a local minimum point in the plurality of local maximum points is determined as a trough. In an embodiment of the present invention, the forward peak sequence is determined according to the plurality of local maximum points along the forward direction, the forward valley sequence is determined according to the plurality of local minimum points along the forward direction, the reverse peak sequence is determined according to the plurality of local maximum points along the reverse direction, and the reverse valley sequence is determined according to the plurality of local minimum points along the reverse direction.
Fig. 3 is a schematic diagram illustrating a plurality of sequences determined according to local extreme points, wherein a positive direction along a time axis is a positive direction and a negative direction is a negative direction based on the time axis.
In the embodiment of the invention, the determined multiple local extreme points are respectively reordered along the forward direction and the reverse direction according to the wave crests and the wave troughs and are determined as a forward wave crest sequence
Figure BDA0002481621390000091
Positive trough sequence
Figure BDA0002481621390000092
Reverse peak sequence
Figure BDA0002481621390000093
And reverse trough sequence
Figure BDA0002481621390000094
And is represented by the following formula (1):
Figure BDA0002481621390000095
where n represents the number of peaks and m represents the number of troughs.
In step S3, a valid left boundary of the pulse waveform data is determined according to the forward peak sequence and the forward valley sequence. FIG. 4 is a flowchart illustrating a process of determining a valid left boundary of pulse waveform data according to an embodiment of the present invention, including steps S31-S32.
In step S31, a forward cumulative standard deviation sequence of the forward peak sequence is determined along the forward direction. In the embodiment of the present invention, a peak is sequentially added from a first peak of the forward peak sequence along the forward direction, and an accumulated standard deviation corresponding to each peak is determined to form the forward accumulated standard deviation sequence.
In the embodiment of the invention, the wave crest sequence is formed from the positive direction
Figure BDA0002481621390000101
Starting with the first peak, based on the average of the accumulated amplitudes of each increment of one peak
Figure BDA0002481621390000102
And the total number of the current accumulated increase wave crest
Figure BDA0002481621390000103
Determining the accumulated standard deviation corresponding to each peak to form a forward accumulated standard deviation sequence
Figure BDA0002481621390000104
Represented by the following formula (2):
Figure BDA0002481621390000105
wherein the content of the first and second substances,
Figure BDA0002481621390000106
the average value of the accumulated amplitudes representing one peak at a time in the positive direction is represented by the following equation (3):
Figure BDA0002481621390000107
in step S32, the valid left boundary is determined according to the forward cumulative standard deviation sequence and the forward trough sequence. Fig. 5 is a flowchart illustrating a process of determining a valid left boundary according to a forward cumulative standard deviation sequence and a forward trough sequence according to an embodiment of the present invention, which includes steps S321 to S323.
In step S321, when one accumulated standard deviation in the forward accumulated standard deviation sequence is greater than or equal to a first multiple of the accumulated standard deviation determined last time, two time points corresponding to two peaks corresponding to the accumulated standard deviation and the accumulated standard deviation determined last time are determined. In the embodiment of the invention, when the accumulated standard deviation of a certain peak is larger than or equal to k of the accumulated standard deviation calculated last time1Determining the time points corresponding to the two wave crests
Figure BDA0002481621390000108
And
Figure BDA0002481621390000109
in the embodiment of the present invention, k1The value of (a) is generally about 3, and the value may be smaller or larger due to different equipment and environments. Unlike the water bottom echo, the water surface echo energy is usually large, and therefore often produces a large sudden change (as shown in FIG. 3) relative to the noise waveform, whereby k is1The value of 3 can better distinguish noise from water surface echo.
In step S322, a time point corresponding to a trough between the two time points is determined according to the forward trough sequence. In the embodiment of the invention, the forward valley sequence is based on
Figure BDA00024816213900001010
Find at these two time points
Figure BDA00024816213900001011
And
Figure BDA00024816213900001012
the time point corresponding to the trough in between is recorded as
Figure BDA00024816213900001013
In step S323, the time point corresponding to the trough is determined as the valid left boundary. In the embodiment of the invention, the time point corresponding to the trough
Figure BDA00024816213900001014
Expressed as the following expression (4), the timing point is determined as the effective left boundary of the detection effective waveform.
Figure BDA0002481621390000111
In the embodiment of the present invention, as shown in fig. 3, when new peak amplitudes are continuously added in the positive direction, the added peak amplitudes have small differences, so the accumulated standard deviation fluctuates around a small amplitude data. When a peak with a large difference in amplitude value suddenly appears, the cumulative standard deviation at the peak is suddenly increased. To ensure that the left boundary of the valid waveform data is obtained, in the embodiment of the present invention, the nearest trough is found from the time point corresponding to the peak back to the left (i.e., in the reverse direction), and the time point corresponding to the trough is determined as the valid left boundary. By adopting the method that the wave crests and the wave troughs are matched with each other correspondingly, the influence of the sampling points belonging to the non-extreme point on the processing result can be effectively avoided, meanwhile, the calculation and judgment of all the sampling points can be avoided, and the calculation efficiency is effectively improved.
In step S4, a valid right boundary of the pulse waveform data is determined according to the inverse peak sequence and the inverse valley sequence. FIG. 6 is a flowchart illustrating a process of determining a valid right boundary of pulse waveform data according to an embodiment of the present invention, including steps S41-S42.
In step S41, when the number of sampling points of the bathymetric survey laser is less than or equal to a preset threshold, determining a reverse accumulated standard deviation sequence of the reverse peak sequence in the reverse direction. In the embodiment of the present invention, when the number of sampling points of the laser pulse is small, that is, the number of sampling points is less than or equal to a preset threshold, for example, when the number of sampling points of the laser pulse is 320, the sequence of accumulated standard deviations of the reverse peak sequence is determined in the reverse direction. The number of samples in each laser pulse of the single-beam laser which is available is 320, and the number of samples of a single pulse wave of a large device with double frequency (a large laser radar such as a laser radar of the LADM-2 of a Shanghai optical machine) is 3000. It is understood that the preset threshold may be set to 800 to 1000, and the present invention is not limited thereto, because the sampling point data of the device is different.
In the embodiment of the present invention, a peak is sequentially added from a first peak of the inverse peak sequence along the inverse direction, and an accumulated standard deviation corresponding to each peak is determined to form the inverse accumulated standard deviation sequence.
In the embodiment of the invention, the reverse peak sequence is adopted
Figure BDA0002481621390000112
Starting with the first peak, based on the average of the accumulated amplitudes of each increment of one peak
Figure BDA0002481621390000113
And the total number of the current accumulated increase wave crest
Figure BDA0002481621390000114
Determining the accumulated standard deviation corresponding to each peak to form a reverse peak accumulated standard deviation sequence
Figure BDA0002481621390000115
It will be appreciated that the sequence of troughs is reversed from
Figure BDA0002481621390000121
Starting from the first trough, based on the average of the accumulated amplitudes of each increment of one trough
Figure BDA0002481621390000122
And the total number of the troughs accumulated and increased currently
Figure BDA0002481621390000123
Determining the accumulated standard deviation corresponding to each wave trough to form a reverse wave trough accumulated standard deviation sequence
Figure BDA0002481621390000124
Represented by the following formula (5):
Figure BDA0002481621390000125
wherein the content of the first and second substances,
Figure BDA0002481621390000126
the average value of the cumulative amplitudes, which represents each time one trough is added in the reverse direction, is represented by the following equation (6):
Figure BDA0002481621390000127
in step S42, the valid right boundary is determined according to the reverse cumulative standard deviation sequence and the reverse trough sequence. Fig. 7 is a schematic flowchart illustrating a process of determining an effective right boundary according to the reverse cumulative standard deviation sequence and the reverse valley sequence, including steps S421 to S423.
In step S421, when one accumulated standard deviation in the reverse accumulated standard deviation sequence is greater than or equal to a second multiple of the accumulated standard deviation determined last time, two time points corresponding to two peaks corresponding to the accumulated standard deviation and the accumulated standard deviation determined last time are determined. In the embodiment of the invention, when the peak sequence is reversed
Figure BDA0002481621390000128
The accumulated standard deviation corresponding to a certain peak in the wave crest is more than or equal to k of the accumulated standard deviation determined by the last calculation2Determining the time points corresponding to the two wave crests
Figure BDA0002481621390000129
And
Figure BDA00024816213900001210
in the embodiment of the present invention, k2The value of (a) is related to many factors, and generally the value of (b) is about 2 to 4. Since the value depends on the magnitude of the systematic noise and random environmental noise of the lidar, as well as the magnitude of the energy amplitude of the water bottom echo signal. However, the size of the water body echo signal relates to the water body depth, the turbidity, the size of the laser radar pulse emission energy, the data acquisition time (day, night, sun, cloudy day), and other factors. It will be appreciated that k is different depending on the equipment and environment2The values of (a) may be smaller or larger, and the invention is not limited thereto.
In step S422, a time point corresponding to a trough between the two time points is determined according to the reverse trough sequence. In the embodiment of the invention, the method is based on reverse valley sequence
Figure BDA00024816213900001211
Find at these two time points
Figure BDA00024816213900001212
And
Figure BDA00024816213900001213
the time points corresponding to the troughs in between are recorded as
Figure BDA00024816213900001214
In step S423, the time point corresponding to the trough is determined as the valid right boundary. In the embodiment of the invention, the time point corresponding to the trough
Figure BDA0002481621390000131
Expressed as the following expression (7), this timing point is determined as the effective right boundary of the detection effective waveform.
Figure BDA0002481621390000132
In the embodiment of the present invention, as shown in fig. 3, when new peak amplitudes are added continuously in a reverse direction, the accumulated standard deviation fluctuates around a small amplitude data because the added peaks have small differences. When a peak with a large amplitude value difference suddenly appears, the corresponding accumulated standard deviation at the peak is suddenly increased. To ensure that the right boundary of the valid data is obtained, the nearest trough is found back from the time point corresponding to the peak to the right (i.e. along the forward direction), and the time point corresponding to the trough is determined as the valid right boundary. By adopting the method that the wave crests and the wave troughs are matched with each other correspondingly, the influence of the sampling points belonging to non-extreme point positions on the processing result can be effectively avoided, meanwhile, the calculation and judgment of all the sampling points can be avoided, and the calculation efficiency is effectively improved.
FIG. 8 is a second flowchart illustrating a process of determining the valid right boundary of the pulse waveform data according to the embodiment of the invention, which includes steps S43 to S44.
In step S43, when the number of sampling points of the bathymetric survey laser is greater than a preset threshold, determining the mean of the peak cumulative standard deviation sequence and the trough cumulative standard deviation sequence from the initial time to the effective left boundary of the pulse waveform data along the forward direction, and determining the reverse peak cumulative standard deviation sequence of the reverse peak sequence and the reverse trough cumulative standard deviation sequence of the reverse trough sequence along the reverse direction, respectively. The reverse peak cumulative standard deviation sequence and the reverse trough cumulative standard deviation sequence may be calculated in the manner described above, and are not described herein again.
Fig. 9 is a schematic diagram of a laser pulse waveform when the number of sampling points is large according to an embodiment of the present invention. In the embodiment of the present invention, when the number of sampling points of each laser pulse is greater than the preset threshold, for example, 3000 sampling points shown in fig. 9, since the sampling points are very dense, that is, each sampling point is very sensitive to echo signals at different times, a peak and a trough tend to increase and decrease synchronously in an echo region at the water bottom, and there is no sudden change, so that a method for detecting an effective right boundary needs to be changed.
Fig. 10 is a flowchart illustrating a process of determining a mean value of a cumulative standard deviation sequence according to an embodiment of the present invention, including steps S431 to S433.
In step S431, sequentially adding one peak from the first peak of the forward peak sequence to the effective left boundary along the forward direction, and determining an accumulated standard deviation corresponding to each peak to form the peak accumulated standard deviation sequence. In the embodiment of the present invention, a peak cumulative standard deviation sequence in an invalid region on the left side of the valid waveform (i.e., a region from the initial time to the valid left boundary) is determined, where the peak cumulative standard deviation can be calculated in the manner described above, and details thereof are not repeated herein. The peak cumulative standard deviation sequence is represented by the following formula (8):
Figure BDA0002481621390000141
in step S432, sequentially increasing one trough from the first trough of the forward trough sequence to the effective left boundary along the forward direction, and determining the cumulative standard deviation corresponding to each trough to form the trough cumulative standard deviation sequence. In the embodiment of the present invention, a valley cumulative standard deviation sequence in an invalid region on the left side of the valid waveform (i.e., a region from the initial time to the valid left boundary) is determined, where the valley cumulative standard deviation can be calculated in the manner described above, and details are not described here again. The trough cumulative standard deviation sequence is represented by the following formula (9):
Figure BDA0002481621390000142
in step S433, the mean of the peak cumulative standard deviation sequence and the trough cumulative standard deviation sequence is determined. In the embodiment of the invention, the mean value is denoted as σmeanExpressed by the following formula (10):
Figure BDA0002481621390000143
wherein, N and M respectively represent the number of peaks and troughs in the interval from the initial time to the effective left boundary.
In step S44, the effective right boundary is determined according to the mean, the reverse peak cumulative standard deviation sequence, the reverse valley cumulative standard deviation sequence, and the reverse valley sequence. Fig. 11 is a flowchart illustrating the determination of the valid right boundary according to the mean, the reverse cumulative standard deviation sequence, the reverse valley cumulative standard deviation sequence and the reverse valley sequence, including steps S441 to S443.
In step S441, when the average of the cumulative standard deviations is greater than or equal to the third multiple of the mean, determining a time point corresponding to the corresponding peak according to the reverse peak sequence, where the average of the cumulative standard deviations is an average of one peak cumulative standard deviation in the reverse peak cumulative standard deviation sequence and one trough cumulative standard deviation in the reverse trough cumulative standard deviation sequence. In the embodiment of the present invention, when one is usedThe average value of the peak accumulated standard deviation and the trough accumulated standard deviation is more than or equal to k3Mean value of multiple σmeanAnd determining the time point corresponding to the peak.
In step S442, a time point corresponding to a trough adjacent to the peak in the forward direction is determined according to the reverse trough sequence
Figure BDA0002481621390000151
In an embodiment of the invention, the method is based on an inverse valley sequence
Figure BDA0002481621390000152
Finding the nearest valley along the reverse direction (i.e. along the forward direction) with the determined peak, and determining the corresponding time point of the valley
Figure BDA0002481621390000153
In step S443, the time point corresponding to the trough is determined
Figure BDA0002481621390000154
Determined as the valid right boundary. In the embodiment of the invention, the time point corresponding to the trough
Figure BDA0002481621390000155
Expressed as the following expression (11), this timing point is determined as the effective right boundary of the detection effective waveform.
Figure BDA0002481621390000156
In the embodiment of the invention, no matter what equipment and environment, the water surface echo energy is strong, so that sudden change (transient enhancement) can be generated, and the extraction of the effective left boundary is easier. As shown in FIG. 3, the invalid region from the initial time to the valid left boundary is the combined noise of the system noise and the environmental random noise, which has the same property as the combined noise after the water bottom echo, and the noise mean and the accumulated standard deviation (σ) have the same sizemean) Thus, it is possible toThe effective right boundary can be effectively extracted by taking the value as a reference, so that the accuracy is improved.
In step S5, the pulse waveform data between the effective left boundary and the effective right boundary is extracted as effective data. In the embodiment of the invention, the waveform data between the determined effective left boundary and the effective right boundary is taken as effective data to be extracted and taken as pretreatment of the data, thereby being beneficial to improving the accuracy of subsequent water depth measurement analysis.
By adopting the method for extracting the water depth measurement laser data, provided by the embodiment of the invention, the accuracy of extracting the waveform effective data can be improved by extracting the local extreme points in the original pulse waveform, reconstructing the forward and reverse wave crest sequences and wave trough sequences according to a plurality of local extreme points, matching the wave crest sequences and the wave trough sequences and extracting the waveform effective left boundary and the waveform effective right boundary according to the corresponding accumulated standard deviation. In addition, the invention does not need to calculate and judge all sampling points, thereby effectively improving the efficiency of the system for processing the waveform. The invention can also count out system errors, can avoid mixing of useless waveform data containing system and random errors in subsequent processing, and effectively improves the success rate and precision of waveform data calculation.
The embodiment of the second aspect of the invention also provides a device for extracting the bathymetric survey laser data. Fig. 12 is a schematic structural diagram of an extraction apparatus 1200 for bathymetric laser data according to an embodiment of the present invention, including an acquisition module 1201, a processing module 1202, and an extraction module 1203.
The obtaining module 1201 is configured to obtain pulse waveform data of the bathymetric laser, and determine a plurality of local extreme points of the pulse waveform data.
The processing module 1202 is configured to determine a forward peak sequence, a forward valley sequence, a reverse peak sequence, and a reverse valley sequence according to the plurality of local extreme points, where a forward direction of the pulse waveform data along a time coordinate axis is a forward direction, and a reverse direction of the pulse waveform data along the time coordinate axis is a reverse direction; further configured to determine an effective left boundary of the pulse waveform data from the forward peak sequence and the forward valley sequence; and is further configured to determine an effective right boundary of the pulse waveform data from the reverse peak sequence and the reverse valley sequence.
The extraction module 1203 is configured to extract the pulse waveform data between the effective left boundary and the effective right boundary as effective data.
In this embodiment of the present invention, the processing module 1202 is further configured to determine a forward cumulative standard deviation sequence of the forward peak sequence along the forward direction; and determining the effective left boundary according to the forward cumulative standard deviation sequence and the forward trough sequence.
In this embodiment of the present invention, the processing module 1202 is further configured to determine a reverse cumulative standard deviation sequence of the reverse peak sequence in the reverse direction when the number of sampling points of the bathymetric survey laser is less than or equal to a preset threshold; and determining the effective right boundary according to the reverse cumulative standard deviation sequence and the reverse valley sequence. The processing module 1202 is further configured to determine, along the forward direction, a mean value of a peak cumulative standard deviation sequence and a trough cumulative standard deviation sequence of the pulse waveform data from an initial time to the effective left boundary when the number of sampling points of the bathymetric laser is greater than a preset threshold, and determine, along the reverse direction, a reverse peak cumulative standard deviation sequence of the reverse peak sequence and a reverse trough cumulative standard deviation sequence of the reverse trough sequence, respectively; and determining the effective right boundary according to the mean value, the reverse peak accumulated standard deviation sequence, the reverse valley accumulated standard deviation sequence and the reverse valley sequence.
For a more specific implementation manner of each module of the apparatus 1200 for extracting bathymetric laser data, reference may be made to the description of the method for extracting bathymetric laser data of the present invention, and similar beneficial effects are obtained, and details are not repeated herein.
An embodiment of a third aspect of the invention provides a water depth measuring method. Fig. 13 is a schematic flow chart of a water depth measuring method according to an embodiment of the present invention, which includes steps S131 to S132.
In step S131, effective data of the bathymetric laser waveform is obtained, and the effective data is obtained by the above-described extraction method of the bathymetric laser data. It can be understood that, in the embodiment of the present invention, the effective left boundary and the effective right boundary of the waveform may be determined in the above manner for the echo pulse signals acquired by the single-beam or multi-beam bathymetry laser radar, so as to extract the effective signals.
In step S132, the depth of the water in the measured area is determined according to the valid data. In the embodiment of the invention, the extracted waveforms in the effective left and right boundaries can be subjected to subsequent processing to complete the water depth measurement of the detection area.
By adopting the water depth measurement method provided by the embodiment of the invention, the original pulse waveform data is preprocessed by using an effective waveform extraction mode, so that the extraction of the effective range of the waveform signal can be effectively improved, and the accuracy and the processing efficiency of water depth measurement are improved. And a large amount of environmental noise and system errors can be avoided, and the resolving success rate and precision of the system are improved.
An embodiment of a fourth aspect of the invention provides a water depth measuring device. Fig. 14 is a schematic structural diagram of a water depth measuring apparatus 1400 according to an embodiment of the present invention, which includes an obtaining module 1401 and a measuring module 1402.
The obtaining module 1401 is configured to obtain effective data of the bathymetric laser waveform, where the effective data is obtained by using the above-described extraction method of the bathymetric laser data.
The measurement module 1402 is configured to determine a depth of a body of water of the measured area according to the valid data.
For a more detailed implementation of each module of the water depth measuring apparatus 1400, reference may be made to the description of the water depth measuring method of the present invention, and similar beneficial effects are obtained, and details are not repeated here.
An embodiment of the fifth aspect of the invention proposes a non-transitory computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method for extracting bathymetry laser data according to the first aspect of the invention or implements the method for bathymetry according to the third aspect of the invention.
Generally, computer instructions for carrying out the methods of the present invention may be carried using any combination of one or more computer-readable storage media. Non-transitory computer readable storage media may include any computer readable medium except for the signal itself, which is temporarily propagating.
A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C + +, and conventional procedural programming languages, such as the "C" programming language or similar programming languages, and in particular may employ Python languages suitable for neural network computing and TensorFlow, PyTorch-based platform frameworks. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider).
An embodiment of a sixth aspect of the present invention provides a computing device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method for training an object detection model with constrained error gradients according to the first aspect of the present invention or implementing the method for object detection with constrained error gradients according to the third aspect of the present invention when executing the program.
The non-transitory computer-readable storage medium and the computing device according to the fifth and sixth aspects of the present invention may be implemented with reference to the contents specifically described in the embodiments of the first aspect or the third aspect of the present invention, and have similar beneficial effects to the object detection model training method with constrained error gradients according to the embodiments of the first aspect of the present invention or the object detection method with constrained error gradients according to the embodiments of the third aspect of the present invention, and are not described herein again.
FIG. 15 illustrates a block diagram of an exemplary computing device suitable for use to implement embodiments of the present disclosure. The computing device 15 shown in fig. 15 is only one example and should not impose any limitations on the functionality or scope of use of embodiments of the disclosure.
As shown in FIG. 8, computing device 15 may be implemented in the form of a general purpose computing device. Components of computing device 15 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that couples various system components including the system memory 28 and the processing unit 16.
Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. These architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus, to name a few.
Computing device 15 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computing device 15 and includes both volatile and nonvolatile media, removable and non-removable media.
Memory 28 may include computer system readable media in the form of volatile Memory, such as Random Access Memory (RAM) 30 and/or cache Memory 32. The computing device 15 may further include other removable/non-removable, volatile/nonvolatile computer-readable storage media. By way of example only, storage system 34 may be used to read from and write to non-removable, nonvolatile magnetic media (not shown, but commonly referred to as a "hard drive"). Although not shown in FIG. 8, a disk drive for reading from and writing to a removable, nonvolatile magnetic disk (e.g., a "floppy disk") and an optical disk drive for reading from or writing to a removable, nonvolatile optical disk (e.g., a Compact disk Read Only memory (CD-ROM), a Digital versatile disk Read Only memory (DVD-ROM), or other optical media) may be provided. In these cases, each drive may be connected to bus 18 by one or more data media interfaces. Memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the disclosure.
A program/utility 40 having a set (at least one) of program modules 42 may be stored, for example, in memory 28, such program modules 42 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which examples or some combination thereof may comprise an implementation of a network environment. Program modules 42 generally perform the functions and/or methodologies of the embodiments described in this disclosure.
Computing device 15 may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), with one or more devices that enable a user to interact with the computer system/server 12, and/or with any devices (e.g., network card, modem, etc.) that enable the computer system/server 12 to communicate with one or more other computing devices. Such communication may be through an input/output (I/O) interface 22. Moreover, computing device 15 may also communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public Network such as the Internet via Network adapter 20. As shown, the network adapter 20 communicates with the other modules of the computing device 15 over the bus 18. It is noted that although not shown, other hardware and/or software modules may be used in conjunction with computing device 15, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, among others.
The processing unit 16 executes various functional applications and data processing, for example, implementing the methods mentioned in the foregoing embodiments, by executing programs stored in the system memory 28.
The computing device of the invention can be a server or a terminal device with limited computing power.
Although embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (18)

1. A method for extracting water depth measurement laser data is characterized by comprising the following steps:
acquiring pulse waveform data of a bathymetric laser, and determining a plurality of local extreme points of the pulse waveform data;
determining a forward peak sequence, a forward valley sequence, a reverse peak sequence and a reverse valley sequence according to the plurality of local extreme points, wherein the forward direction of the pulse waveform data along the time coordinate axis is taken as the forward direction, and the reverse direction of the pulse waveform data along the time coordinate axis is taken as the reverse direction;
determining an effective left boundary of the pulse waveform data according to the forward peak sequence and the forward valley sequence;
determining an effective right boundary of the pulse waveform data according to the reverse peak sequence and the reverse valley sequence;
extracting the pulse waveform data between the effective left boundary and the effective right boundary as effective data.
2. The method for extracting bathymetry laser data according to claim 1, wherein the forward peak sequence, the forward valley sequence, the reverse peak sequence and the reverse valley sequence are determined according to the plurality of local extreme points, a local maximum point in the plurality of local extreme points is determined as a peak, and a local minimum point in the plurality of local extreme points is determined as a valley.
3. The method of claim 2, wherein the determining the forward peak sequence, the forward valley sequence, the reverse peak sequence and the reverse valley sequence according to the plurality of local extreme points comprises: determining the forward peak sequence according to the plurality of local maximum points along the forward direction, determining the forward valley sequence according to the plurality of local minimum points along the forward direction, determining the reverse peak sequence according to the plurality of local maximum points along the reverse direction, and determining the reverse valley sequence according to the plurality of local minimum points along the reverse direction.
4. The method of claim 1, wherein the determining the valid left boundary of the pulse waveform data from the forward peak sequence and the forward valley sequence comprises:
determining a forward cumulative standard deviation sequence of the forward peak sequence along the forward direction;
and determining the effective left boundary according to the forward cumulative standard deviation sequence and the forward trough sequence.
5. The method of claim 4, wherein determining the forward cumulative standard deviation sequence of the forward peak sequence along the forward direction comprises: and sequentially adding a peak from the first peak of the forward peak sequence along the forward direction, and determining the accumulated standard deviation corresponding to each peak to form the forward accumulated standard deviation sequence.
6. The method of claim 4, wherein the determining the valid left boundary from the forward cumulative standard deviation sequence and the forward trough sequence comprises:
when one accumulated standard deviation in the forward accumulated standard deviation sequence is larger than or equal to a first multiple of the accumulated standard deviation determined last time, determining two time points corresponding to two wave crests corresponding to the accumulated standard deviation and the accumulated standard deviation determined last time;
determining a time point corresponding to a trough between the two time points according to the forward trough sequence;
and determining the time point corresponding to the trough as the effective left boundary.
7. The method of claim 1, wherein the determining the effective right boundary of the pulse waveform data from the reverse peak sequence and the reverse valley sequence comprises:
when the number of sampling points of the bathymetric survey laser is less than or equal to a preset threshold value, determining a reverse accumulated standard deviation sequence of the reverse peak sequence along the reverse direction;
and determining the effective right boundary according to the reverse cumulative standard deviation sequence and the reverse valley sequence.
8. The method of claim 7, wherein determining the sequence of inverse cumulative standard deviations of the sequence of inverse peaks in the inverse direction comprises: and sequentially adding a peak from the first peak of the reverse peak sequence along the reverse direction, and determining the accumulated standard deviation corresponding to each peak to form the reverse accumulated standard deviation sequence.
9. The method of claim 7, wherein the determining the valid right boundary from the reverse cumulative standard deviation sequence and the reverse trough sequence comprises:
when one accumulated standard deviation in the reverse accumulated standard deviation sequence is larger than or equal to a second multiple of the accumulated standard deviation determined last time, determining two time points corresponding to two wave crests corresponding to the accumulated standard deviation and the accumulated standard deviation determined last time;
determining a time point corresponding to a trough between the two time points according to the reverse trough sequence;
and determining the time point corresponding to the trough as the effective right boundary.
10. The method of claim 1, wherein the determining the effective right boundary of the pulse waveform data from the reverse peak sequence and the reverse valley sequence comprises:
when the number of sampling points of the bathymetric survey laser is larger than a preset threshold value, determining the mean value of a peak accumulated standard deviation sequence and a trough accumulated standard deviation sequence from the initial moment to the effective left boundary of the pulse waveform data along the forward direction, and respectively determining a reverse peak accumulated standard deviation sequence of the reverse peak sequence and a reverse trough accumulated standard deviation sequence of the reverse trough sequence along the reverse direction;
and determining the effective right boundary according to the mean value, the reverse peak accumulated standard deviation sequence, the reverse valley accumulated standard deviation sequence and the reverse valley sequence.
11. The method of claim 10, wherein the determining the mean of the sequence of peak and trough accumulated standard deviations of the pulse waveform data from the initial time to within the effective left boundary along the forward direction comprises:
sequentially increasing a peak from the first peak of the forward peak sequence to the effective left boundary along the forward direction, and determining the accumulated standard deviation corresponding to each peak to form the peak accumulated standard deviation sequence;
sequentially increasing a trough from the first trough of the forward trough sequence to the effective left boundary along the forward direction, and determining the accumulated standard deviation corresponding to each trough to form the trough accumulated standard deviation sequence;
and determining the mean value of the peak accumulated standard deviation sequence and the trough accumulated standard deviation sequence.
12. The method of claim 10, wherein the determining the reverse peak accumulated standard deviation sequence of the reverse peak sequence and the reverse valley accumulated standard deviation sequence of the reverse valley sequence along the reverse direction respectively comprises: sequentially adding a peak from the first peak of the reverse peak sequence along the reverse direction, and determining the accumulated standard deviation corresponding to each peak to form the reverse peak accumulated standard deviation sequence; and sequentially increasing a trough from the first trough of the reverse trough sequence along the reverse direction, and determining the accumulated standard deviation corresponding to each trough to form the reverse trough accumulated standard deviation sequence.
13. The method of claim 10, wherein determining the valid right boundary from the mean, the reverse peak accumulated standard deviation sequence, the reverse trough accumulated standard deviation sequence, and the reverse trough sequence comprises:
when the average value of the accumulated standard deviations is larger than or equal to a third multiple of the average value, determining a time point corresponding to the corresponding peak according to the reverse peak sequence, wherein the average value of the accumulated standard deviations is the average value of one peak accumulated standard deviation in the reverse peak accumulated standard deviation sequence and one trough accumulated standard deviation in the reverse trough accumulated standard deviation sequence;
determining a time point corresponding to a trough adjacent to the peak along the forward direction according to the reverse trough sequence;
and determining the time point corresponding to the trough as the effective right boundary.
14. An extraction device for bathymetric survey laser data, comprising:
the acquisition module is used for acquiring pulse waveform data of the water depth measuring laser and determining a plurality of local extreme points of the pulse waveform data;
the processing module is used for determining a forward peak sequence, a forward valley sequence, a reverse peak sequence and a reverse valley sequence according to the local extreme points, wherein the forward direction of the pulse waveform data along a time coordinate axis is taken as the forward direction, and the reverse direction of the pulse waveform data along the time coordinate axis is taken as the reverse direction; further configured to determine an effective left boundary of the pulse waveform data from the forward peak sequence and the forward valley sequence; further configured to determine a valid right boundary of the pulse waveform data from the reverse peak sequence and the reverse valley sequence;
an extraction module to extract the pulse waveform data between the effective left boundary and the effective right boundary as effective data.
15. A method of bathymetry, comprising:
obtaining effective data of a bathymetry laser waveform, wherein the effective data is obtained by adopting the extraction method of the bathymetry laser data according to any one of claims 1-13;
and determining the water depth of the measured area according to the effective data.
16. A bathymetric survey apparatus, comprising:
an obtaining module, configured to obtain effective data of a bathymetry laser waveform, where the effective data is obtained by using the method for extracting bathymetry laser data according to any one of claims 1 to 13;
and the measuring module is used for determining the water depth of the measured area according to the effective data.
17. A non-transitory computer-readable storage medium having stored thereon a computer program, wherein the computer program, when executed by a processor, implements the method for extracting bathymetry laser data according to any one of claims 1-13, or implements the method for bathymetry according to claim 15.
18. A computing 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 program implements the method for bathymetry laser data extraction according to any one of claims 1-13 or implements the method for bathymetry according to claim 15.
CN202010380093.0A 2020-05-08 2020-05-08 Extraction method of water depth measurement laser data, water depth measurement method and device Active CN111551952B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010380093.0A CN111551952B (en) 2020-05-08 2020-05-08 Extraction method of water depth measurement laser data, water depth measurement method and device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010380093.0A CN111551952B (en) 2020-05-08 2020-05-08 Extraction method of water depth measurement laser data, water depth measurement method and device

Publications (2)

Publication Number Publication Date
CN111551952A true CN111551952A (en) 2020-08-18
CN111551952B CN111551952B (en) 2022-10-18

Family

ID=72003465

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010380093.0A Active CN111551952B (en) 2020-05-08 2020-05-08 Extraction method of water depth measurement laser data, water depth measurement method and device

Country Status (1)

Country Link
CN (1) CN111551952B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112097861A (en) * 2020-09-11 2020-12-18 北京妙思特仪表有限公司 Threshold voltage determination method and device and magnetostrictive liquid level meter
CN112648932A (en) * 2020-12-04 2021-04-13 武汉锐科光纤激光技术股份有限公司 Method for detecting stripe depth of laser cutting surface
CN113608195A (en) * 2021-10-08 2021-11-05 中国地质大学（武汉） Laser radar full waveform data decomposition sounding method and device and electronic equipment
CN114955579A (en) * 2022-04-12 2022-08-30 三一海洋重工有限公司 Shell position calibration method, device, equipment and system for container yard
CN116609759A (en) * 2023-07-21 2023-08-18 自然资源部第一海洋研究所 Method and system for enhancing and identifying airborne laser sounding seabed weak echo
CN117031442A (en) * 2023-10-08 2023-11-10 中国地质大学（武汉） Laser radar water area topography measurement method and device integrating multichannel waveform data

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102722640A (en) * 2012-05-24 2012-10-10 中交第二公路勘察设计研究院有限公司 Airborne laser waveform data decomposition algorithm considering adjacent waveform information
CN102854445A (en) * 2012-10-18 2013-01-02 上海市电力公司 Method for extracting waveform feature of local discharge pulse current
CN103989462A (en) * 2014-04-04 2014-08-20 辛勤 Method for extracting first characteristic point and second characteristic point of pulse waveform
CN109490342A (en) * 2018-11-13 2019-03-19 中国科学院沈阳自动化研究所 A method of liquid dielectric is assessed based on guide wave radar liquid level gauge
CN109864705A (en) * 2019-01-07 2019-06-11 平安科技（深圳）有限公司 The method, apparatus and computer equipment that pulse wave is filtered
CN110532975A (en) * 2019-09-03 2019-12-03 武汉天擎空间信息技术有限公司 TIN filter correction method based on Full wave shape airborne laser radar data
CN110794424A (en) * 2019-11-13 2020-02-14 湖北大学 Full-waveform airborne laser radar ground feature classification method and system based on feature selection

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102722640A (en) * 2012-05-24 2012-10-10 中交第二公路勘察设计研究院有限公司 Airborne laser waveform data decomposition algorithm considering adjacent waveform information
CN102854445A (en) * 2012-10-18 2013-01-02 上海市电力公司 Method for extracting waveform feature of local discharge pulse current
CN103989462A (en) * 2014-04-04 2014-08-20 辛勤 Method for extracting first characteristic point and second characteristic point of pulse waveform
CN109490342A (en) * 2018-11-13 2019-03-19 中国科学院沈阳自动化研究所 A method of liquid dielectric is assessed based on guide wave radar liquid level gauge
CN109864705A (en) * 2019-01-07 2019-06-11 平安科技（深圳）有限公司 The method, apparatus and computer equipment that pulse wave is filtered
CN110532975A (en) * 2019-09-03 2019-12-03 武汉天擎空间信息技术有限公司 TIN filter correction method based on Full wave shape airborne laser radar data
CN110794424A (en) * 2019-11-13 2020-02-14 湖北大学 Full-waveform airborne laser radar ground feature classification method and system based on feature selection

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112097861A (en) * 2020-09-11 2020-12-18 北京妙思特仪表有限公司 Threshold voltage determination method and device and magnetostrictive liquid level meter
CN112648932A (en) * 2020-12-04 2021-04-13 武汉锐科光纤激光技术股份有限公司 Method for detecting stripe depth of laser cutting surface
CN113608195A (en) * 2021-10-08 2021-11-05 中国地质大学（武汉） Laser radar full waveform data decomposition sounding method and device and electronic equipment
CN114955579A (en) * 2022-04-12 2022-08-30 三一海洋重工有限公司 Shell position calibration method, device, equipment and system for container yard
CN116609759A (en) * 2023-07-21 2023-08-18 自然资源部第一海洋研究所 Method and system for enhancing and identifying airborne laser sounding seabed weak echo
CN116609759B (en) * 2023-07-21 2023-10-31 自然资源部第一海洋研究所 Method and system for enhancing and identifying airborne laser sounding seabed weak echo
CN117031442A (en) * 2023-10-08 2023-11-10 中国地质大学（武汉） Laser radar water area topography measurement method and device integrating multichannel waveform data
CN117031442B (en) * 2023-10-08 2024-01-02 中国地质大学（武汉） Laser radar water area topography measurement method and device integrating multichannel waveform data

Also Published As

Publication number Publication date
CN111551952B (en) 2022-10-18

Similar Documents

Publication Publication Date Title
CN111551952B (en) Extraction method of water depth measurement laser data, water depth measurement method and device
US11815625B2 (en) Methods and devices for correcting underwater photon displacement and for depth sounding with single-photon Lidar
CN109239709B (en) Autonomous construction method for local environment map of unmanned ship
CN104749594B (en) A kind of non-poor cycle-slip detection and repair method and device of GPS double frequency
CN103592650B (en) The three-dimensional sonar imaging system of graphic based processor and three-D imaging method thereof
CN105572676A (en) Seine object fish shoal tracking method based on horizontal fishgraph images
CN111399642A (en) Gesture recognition method and device, mobile terminal and storage medium
CN103513244B (en) A kind of multi-frame phase coherence accumulation target tracking-before-detecting method based on dynamic programming
CN106052795B (en) A kind of method and device obtaining tidal level
CN103292792B (en) Actual measurement SVP reconstruction method suitable for submarine detection and pseudo-landform processing
CN110673108B (en) Airborne marine laser radar signal processing method based on iteration Klett
CN113608195B (en) Laser radar full waveform data decomposition sounding method and device and electronic equipment
CN105204026A (en) Single horizontal array passive speed measurement and distance measurement device based on sound field interference fringe and method
CN112526490B (en) Underwater small target sonar detection system and method based on computer vision
CN112965060A (en) Detection method and device for vital sign parameters and method for detecting physical sign points
CN116907509A (en) AUV underwater auxiliary navigation method, system, equipment and medium based on image matching
CN111708005A (en) Underwater photon displacement correction and depth measurement method and device for single photon laser radar
CN116338628B (en) Laser radar sounding method and device based on learning architecture and electronic equipment
CN111665487A (en) Underwater photon displacement correction and depth measurement method and device for single photon laser radar
CN115015895A (en) Method and system for calibrating position of horizontal array element
Kim et al. Waveform decomposition of airborne bathymetric LiDAR by estimating potential peaks
CN102183767A (en) Three-dimensional digital fish finder system based on USB (universal serial bus)
CN113075633A (en) Target positioning method based on distance-pitching joint dictionary
CN112799071A (en) Method and device for detecting underwater position
CN103487794B (en) A kind of underwater reverberation suppression method based on wavelet package transforms

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant