阅读说明：本技术 海上目标位置测量方法 (Offshore target position measuring method ) 是由 余毅 李铭扬 张涛 陈忠 郭鑫 王成 于 2021-07-14 设计创作，主要内容包括：本发明提供一种海上目标位置测量方法,包括以下步骤：S1连续测量第一测量船、第二测量船和合作靶船的大地坐标；S2将第一测量船、第二测量船和合作靶船的大地坐标转换成地心直角坐标；计算合作靶船的理论俯仰角和方位角；S3通过第一测量船第二测量船拍摄图像,根据像素点分别计算被测目标水平脱靶量和垂直脱靶量；S4计算被测目标的理论俯仰角和方位角；S5构建第一圆锥体相交方程和第二圆锥体相交方程；S6建立球面方程；S7构建迭代求解模型,计算得到被测目标的坐标。本发明无需使用平台局部基准,利用圆锥交会测量系统,简化现有摄影测量学后方交会的测量模式,为海上目标落点的测量系统提供一种简单、便捷、精确的测量方法。(The invention provides a method for measuring the position of an offshore target, which comprises the following steps: s1 continuously measuring geodetic coordinates of the first measuring ship, the second measuring ship and the cooperative target ship; s2, converting the geodetic coordinates of the first survey ship, the second survey ship and the cooperative target ship into geocentric rectangular coordinates; calculating a theoretical pitch angle and an azimuth angle of the cooperative target ship; s3, shooting images through the first measuring vessel and the second measuring vessel, and respectively calculating the horizontal miss distance and the vertical miss distance of the measured object according to pixel points; s4, calculating a theoretical pitch angle and an azimuth angle of the measured target; s5, constructing a first cone intersection equation and a second cone intersection equation; s6, establishing a spherical equation; and S7, constructing an iterative solution model, and calculating to obtain the coordinates of the measured target. According to the invention, a local reference of a platform is not needed, a cone intersection measurement system is utilized, the measurement mode of the existing photogrammetry rear intersection is simplified, and a simple, convenient and accurate measurement method is provided for a measurement system of a marine target landing point.)

1. A method for measuring the position of an offshore target, which is characterized by comprising the following steps:

s1, continuously measuring the geodetic coordinates of the first measuring ship, the second measuring ship and the cooperative target ship corresponding to time points by using a shipborne satellite positioning system;

s2, converting the geodetic coordinates of the first survey ship, the second survey ship and the cooperation target ship into geocentric rectangular coordinates; continuously calculating theoretical pitch angles and azimuth angles of specified target points of the cooperative target ship for the first measuring ship and the second measuring ship respectively corresponding to time points;

s3, shooting images through a first camera carried by the first measuring ship and a second camera carried by the second measuring ship, wherein the first camera and the second camera adopt the same focal length to shoot images of a measured target and the cooperation target ship in real time to respectively obtain a first image and a second image which simultaneously contain the cooperation target ship and the measured target; in the first image and the second image, respectively calculating the horizontal miss distance and the vertical miss distance of the measured object relative to the center of the first image and the center of the second image according to pixel points;

s4, calculating theoretical pitch angles and azimuth angles of the measured target relative to the first measuring ship and the second measuring ship according to the theoretical pitch angles and azimuth angles of the cooperative target ship relative to the first measuring ship and the second measuring ship respectively, and the horizontal miss distance and the vertical miss distance of the measured target relative to the center of the first image and the center of the second image respectively; calculating a first included angle which takes the position of the first camera as a vertex and takes a connecting line with a specified target point of the target to be detected and a connecting line with a specified target point of the cooperation target ship as two sides; calculating a second included angle which takes the position of the second camera as a vertex and takes a connecting line with a specified target point of the target to be detected and a connecting line with a specified target point of the cooperation target ship as two sides;

s5, constructing a first cone intersection equation and a second cone intersection equation according to the first included angle, the second included angle, the geocentric rectangular coordinate of the first survey ship, the geocentric rectangular coordinate of the second survey ship and the geocentric rectangular coordinate of the cooperation target ship;

s6, analyzing and rounding according to pixel points according to the first image and the second image to obtain the elevation of the cooperation target ship and the elevation of the target to be measured, and establishing a spherical equation by combining the geocentric rectangular coordinates of the cooperation target ship;

s7, according to the first cone intersection equation, the second cone intersection equation and the spherical equation, respectively importing the geocentric rectangular coordinate of the first survey ship, the geocentric rectangular coordinate of the second survey ship, the geocentric rectangular coordinate of the cooperation target ship, the first included angle, the second included angle, the elevation of the cooperation target ship and the elevation of the measured target corresponding to each time point, constructing an iterative solution model, and obtaining the geocentric rectangular coordinate of the measured target after calculation.

2. An offshore target location measurement method as set forth in claim 1, wherein in step S2, the designated target point of the cooperative target vessel is determined by a centroid of the cooperative target vessel imaged in the image; the formula for calculating the azimuth angle and the theoretical pitch angle of the specified target point of the cooperative target ship for the first measuring ship and the second measuring ship respectively is as follows:

wherein (X)₁,Y₁,Z₁) Is the geocentric rectangular coordinate of the first survey vessel C1, (X)₂,Y₂,Z₂) Is the geocentric rectangular coordinate of the second survey vessel C2, (X)₃,Y₃,Z₃) Is the geocentric rectangular coordinate, E, of the cooperative target vessel B3_C1For the theoretical pitch angle of the cooperative target vessel to the first survey vessel, A_C1Azimuth angle for said cooperative target vessel to said first survey vessel, E_C2For the theoretical pitch angle of the cooperative target vessel to the second survey vessel, A_C2Azimuth angle for the cooperative target vessel to the second measurement vessel.

3. The offshore target location measurement method of claim 1, wherein in step S4, the formula for calculating the azimuth angle and the theoretical pitch angle of the measured target relative to the first measurement vessel and the second measurement vessel and calculating the first angle and the second angle is as follows:

wherein (x)_t1，y_t1) (x) the horizontal and vertical miss distance of the measured object with respect to the center of the first image_t2，y_t2) The horizontal miss distance and the vertical miss distance, alpha, of the measured object relative to the center of the second image₁And alpha₂For alternative process quantities in the calculation, f is the focal length of the first and second cameras when capturing images, E₁Is a theoretical pitch angle of the measured object relative to the first measuring vessel, A₁Azimuth angle of the measured object relative to the first measuring vessel, E₂Is the theoretical pitch angle of the measured object relative to the second measuring vessel, A₂For the azimuth angle, theta, of the object to be measured relative to the second measuring vessel₁Is the first angle theta₂Is the second included angle.

4. The offshore target location measurement method of claim 1, wherein in step S5, the first cone intersection equation and the second cone intersection equation are:

wherein, (X, Y, Z) represents the geocentric rectangular coordinates of the measured target, and all the (X, Y, Z) represents unknown quantities.

5. The offshore object position measuring method of claim 1, wherein in step S6, the spherical equation is:

wherein H_B3For the elevation of said cooperative target vessel, H_HBAnd the elevation of the measured target is obtained.

Technical Field

The invention relates to the field of target position measurement, in particular to a method for measuring a marine target position.

Background

The traditional method for measuring the position of the target at sea mainly comprises the steps that the measurement is carried out in a coastal sea area, an optical instrument is usually used for measurement in the coastal sea area when the weather is good and the storm is small, and the Euler angle in elements outside a camera cannot be directly calculated by a theodolite shaft angle encoder when a measuring ship is placed on a target ship platform because the measuring ship swings indefinitely; the main measurement means adopted at present comprise radar ranging, laser ranging and optical measurement. Because ships loaded with measuring instruments shake under the action of sea waves and sea winds, the sea surface radar and laser ranging have much lower marine measurement precision than land measurement positioning precision, and optical measurement needs to be provided with local references for measuring three angles of yaw, pitch and roll generated during ship shaking, so that the cost is very high. In order to improve the measurement precision, optical intersection positioning is adopted, the influence of the external environment on the system is reduced, and the method for measuring the high-precision target position based on the cone angle intersection has important research significance.

Disclosure of Invention

The invention provides a method for measuring the position of an offshore target.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

the invention provides a method for measuring the position of an offshore target, which comprises the following steps:

s1, continuously measuring the geodetic coordinates of the first measuring ship, the second measuring ship and the cooperative target ship corresponding to time points by using a shipborne satellite positioning system;

s2, converting the geodetic coordinates of the first survey ship, the second survey ship and the cooperative target ship into geocentric rectangular coordinates; continuously calculating theoretical pitch angles and azimuth angles of specified target points of the cooperative target ship for the first measuring ship and the second measuring ship respectively corresponding to time points;

s3, shooting images through a first camera carried by a first measuring ship and a second camera carried by a second measuring ship, wherein the first camera and the second camera adopt the same focal length to shoot images of a measured target and a cooperation target ship in real time to respectively obtain a first image and a second image which simultaneously comprise the cooperation target ship and the measured target; in the first image and the second image, respectively calculating the horizontal miss distance and the vertical miss distance of the measured object relative to the center of the first image and the center of the second image according to the pixel points;

s4, respectively calculating theoretical pitch angles and azimuth angles of the measured object relative to the first measuring ship and the second measuring ship according to the theoretical pitch angles and azimuth angles of the cooperative target ship relative to the first measuring ship and the second measuring ship, the horizontal miss distance and the vertical miss distance of the measured object relative to the center of the first image and the center of the second image; calculating a first included angle which takes the position of the first camera as a vertex and takes a connecting line with a specified target point of the target to be detected and a connecting line with a specified target point of the cooperative target ship as two sides; calculating a second included angle which takes the position of the second camera as a vertex and takes a connecting line with a specified target point of the target to be detected and a connecting line with a specified target point of the cooperative target ship as two sides;

s5, constructing a first cone intersection equation and a second cone intersection equation according to the first included angle, the second included angle, the geocentric rectangular coordinate of the first measuring ship, the geocentric rectangular coordinate of the second measuring ship and the geocentric rectangular coordinate of the cooperation target ship;

s6, analyzing and rounding according to pixel points according to the first image and the second image to obtain the elevation of the cooperative target ship and the elevation of the target to be measured, and establishing a spherical equation by combining the geocentric rectangular coordinates of the cooperative target ship;

s7, according to the first cone intersection equation, the second cone intersection equation and the spherical equation, respectively importing the geocentric rectangular coordinate of the first survey ship, the geocentric rectangular coordinate of the second survey ship, the geocentric rectangular coordinate of the cooperative target ship, the first included angle, the second included angle, the elevation of the cooperative target ship and the elevation of the measured target corresponding to each time point, constructing an iterative solution model, and calculating to obtain the geocentric rectangular coordinate of the measured target.

Preferably, in step S2, the specified target point of the cooperation target ship is determined by the centroid of the cooperation target ship imaged in the image; the formula for calculating the azimuth angle and the theoretical pitch angle of the specified target point of the cooperative target ship relative to the first measuring ship and the second measuring ship respectively is as follows:

wherein (X)₁,Y₁,Z₁) Is the geocentric rectangular coordinate of the first survey vessel C1, (X)₂,Y₂,Z₂) Is the geocentric rectangular coordinate of the second survey vessel C2, (X)₃,Y₃,Z₃) Is the geocentric rectangular coordinate, E, of the cooperative target vessel B3_C1Theoretical pitch angle for the cooperative target vessel for the first survey vessel, A_C1Azimuth angle of the cooperative target vessel to the first survey vessel, E_C2Theoretical pitch angle for the cooperative target vessel to the second survey vessel, A_C2The azimuth of the cooperative target vessel to the second survey vessel.

Preferably, in step S4, the formula for calculating the azimuth angle and the theoretical pitch angle of the measured object relative to the first measuring vessel and the second measuring vessel and calculating the first included angle and the second included angle is:

wherein (x)_t1，y_t1) The horizontal miss distance and the vertical miss distance of the measured object relative to the center of the first image are (x)_t2，y_t2) The horizontal and vertical miss distance, alpha, of the object to be measured with respect to the center of the second image₁And alpha₂For the alternative process quantities in the calculation, f is the focal length of the first and second cameras when capturing the images, E₁Is the theoretical pitch angle of the measured object relative to the first measuring vessel, A₁Azimuth of the object to be measured with respect to the first measuring vessel, E₂Is the theoretical pitch angle of the measured object relative to the second measuring vessel, A₂Azimuth angle theta of the measured object relative to the second measuring vessel₁Is a first angle theta₂Is the second included angle.

Preferably, in step S5, the first cone intersection equation and the second cone intersection equation are:

wherein, (X, Y, Z) represents the geocentric rectangular coordinates of the measured target, and all the (X, Y, Z) are unknown quantities.

Preferably, in step S6, the spherical equation is:

wherein H_B3For the elevation of a cooperative target vessel, H_HBIs the elevation of the measured target.

The invention can obtain the following technical effects:

(1) the invention solves the problem that the Euler angle in the elements outside the camera cannot be solved directly by a theodolite shaft angle encoder when the theodolite is placed on a target ship platform, and solves the problem that the target falling point coordinate cannot be solved without satellite positioning assistance.

(2) In the conventional scheme, a high-precision platform local reference system is required to be adopted for measuring three angles of yaw, pitch and roll generated by ship rolling, the measured data are processed and then transmitted to a servo tracking subsystem, and stable tracking of the target is realized without using a platform local reference.

(3) When the photoelectric theodolite equipment is not available, the invention can adopt a camera to shoot, thereby simplifying the system and saving the cost.

(4) The invention simplifies the measurement mode of back intersection in the existing photogrammetry by using the cone intersection measurement method, and provides a simple, convenient and accurate measurement method for the measurement system of the target landing point on the sea.

Drawings

FIG. 1 is a schematic flow diagram of a method of offshore target location measurement according to one embodiment of the present invention;

FIG. 2 is a schematic two-dimensional plan view of an offshore target location measurement method according to one embodiment of the present invention;

wherein the reference numerals include: a first survey vessel C1, a second survey vessel C2, a cooperative target vessel B3, a measured target HB and a first included angle theta₁A second angle theta₂。

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same blocks. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.

The following detailed description of the operation of the present invention is provided with reference to fig. 1 and 2:

the invention provides a method for measuring the position of an offshore target, which specifically comprises the following steps:

and S1, continuously measuring the geodetic coordinates of the first survey vessel C1, the second survey vessel C2 and the cooperative target vessel B3 corresponding to the time point by using the shipborne satellite positioning system.

Since the first survey vessel C1, the second survey vessel C2 and the cooperative target vessel B3 are continuously sailing at sea, the geodetic coordinates of the three vessels displayed by the shipborne satellite positioning system are constantly changed, and thus, the specific geodetic coordinates of the three vessels at this time need to be continuously recorded corresponding to the specific time point of the survey.

S2, converting geodetic coordinates of the first survey vessel C1, the second survey vessel C2 and the cooperative target vessel B3 into geocentric rectangular coordinates; theoretical pitch and azimuth angles of the designated target points of the cooperative target vessel B3 for the first survey vessel C1 and the second survey vessel C2, respectively, are continuously calculated corresponding to the points in time.

For the geodetic coordinates of a set of first survey vessel C1, second survey vessel C2, and cooperative target vessel B3 measured at the same time, the geodetic coordinates of the three vessels are converted to geocentric rectangular coordinates in the following manner:

the geodetic coordinate system is a coordinate system established by taking the reference ellipsoid as a datum plane in geodetic surveying. The location of the ground point is represented by a geodetic latitude, a geodetic longitude and a geodetic height. The geodetic latitude, geodetic longitude and geodetic height are each represented by the capital english letter B, L, H. Ground point geodetic latitude B: 0 ° -90 °, ground point geodetic longitude L: 0 degree to 360 degrees or 0 degree to plus or minus 180 degrees, ground point ground height H: may be positive or negative.

The earth center rectangular coordinate system is an inertial coordinate system, the origin is selected at the earth center, the X axis points to the original meridian along the equatorial plane, the Z axis points to the north pole along the earth rotation axis, and the Y axis is vertical to the X axis in the equatorial plane and forms a right-hand coordinate system.

Under the same reference ellipsoid, the conversion formula of the geodetic coordinates (B, L, H) and the geocentric rectangular coordinates (x, y, z) is as follows:

wherein: n is the curvature radius of the ellipsoidal unitary mortise ring,

a is the longer half axis of the earth ellipsoid: a 6378137m

b is the minor semi-axis of the earth ellipsoid: 6356752m

e is the first eccentricity: e 1/298.257

Using the conversion relationship between the geodetic coordinates and the rectangular coordinates of the geocentric coordinates, C1 (X) in the rectangular coordinates of the geocentric coordinates at that time is calculated₁,Y₁,Z₁)、C2(X₂,Y₂,Z₂)、B3(X₃,Y₃,Z₃)。

The designated target point for cooperative target vessel B3 is determined by the centroid of cooperative target vessel B3 as imaged in fig. 2.

The formula for calculating the azimuth and theoretical pitch angles of the designated target point of the cooperative target vessel B3 for the first survey vessel C1 and the second survey vessel C2, respectively, is:

wherein (X)₁,Y₁,Z₁) Is the geocentric rectangular coordinate of the first survey vessel C1, (X)₂,Y₂,Z₂) Is the second measurementGeocentric Cartesian coordinates of Ship C2, (X)₃,Y₃,Z₃) Is the geocentric rectangular coordinate, E, of the cooperative target vessel B3_C1For the theoretical pitch angle, A, of the cooperative target vessel B3 with respect to the first survey vessel C1_C1For the azimuth of cooperative target vessel B3 to first survey vessel C1, E_C2For the theoretical pitch angle, A, of the cooperative target vessel B3 with respect to the second survey vessel C2_C2Azimuth angle for cooperative target vessel B3 to second survey vessel C2.

Using the above formula, the theoretical pitch angle E of the designated target point of the cooperative target ship B3 at this time with respect to the first survey ship C1 is calculated_C1Azimuth A of the designated target point of cooperative target vessel B3 for first survey vessel C1_C1Theoretical Pitch E of the designated target Point of cooperative target vessel B3 to second survey vessel C2_C2Azimuth A of the designated target point of cooperative target vessel B3 for second survey vessel C2_C2。

S3, shooting images through a first camera carried by a first survey vessel C1 and a second camera carried by a second survey vessel C2, wherein the first camera and the second camera adopt the same focal length to shoot images of a measured target HB and a cooperative target vessel B3 in real time to respectively obtain a first image and a second image which simultaneously contain the cooperative target vessel B3 and the measured target HB; and respectively calculating the horizontal miss distance and the vertical miss distance of the measured target HB relative to the center of the first image and the center of the second image in the first image and the second image according to the pixel points.

In the embodiment of the invention, because the fields of view of the first camera and the second camera are large, the falling point of the measured target HB and the cooperative target ship B3 are imaged in the central area of the fields of view as much as possible, and the target image sequence is recorded in real time corresponding to the time point.

In the obtained image, the centroid of the measured target HB image is taken as a designated target point, the image center is taken as an origin, the horizontal direction is taken as an X axis, the vertical direction is taken as a Y axis, and the horizontal miss distance and the vertical miss distance of the measured target HB relative to the image center are calculated according to the proportional relation between the pixel points and the image field size.

Through the above process, the horizontal miss distance x of the measured target HB with respect to the center of the first image is obtained corresponding to the time point_t1And vertical miss distance y_t1Is denoted as (x)_t1，y_t1) (ii) a Horizontal miss distance x of measured target HB with respect to the center of second image_t2And vertical miss distance y_t2Is denoted as (x)_t2，y_t2)。

S4, respectively calculating the theoretical pitch angle and the azimuth angle of the measured target HB relative to the first measuring ship C1 and the second measuring ship C2 according to the theoretical pitch angle and the azimuth angle of the cooperative target ship B3 relative to the first measuring ship C1 and the second measuring ship C2, the horizontal miss distance and the vertical miss distance of the measured target HB relative to the center of the first image and the center of the second image; calculating a first angle theta between a line connecting the first camera position as a vertex and the designated target point of the target HB to be measured and a line connecting the designated target point of the cooperative target ship B3₁(see FIG. 2); calculating a second angle theta between a line connecting the designated target point of the target HB to be measured and a line connecting the designated target point of the cooperative target ship B3 with the second camera position as a vertex₂(see fig. 2).

Respectively calculating the azimuth angle and the theoretical pitch angle of the measured target HB relative to the first measuring vessel C1 and the second measuring vessel C2 and calculating a first included angle theta₁And a second angle theta₂The formula of (1) is as follows:

wherein (x)_t1，y_t1) The horizontal miss distance and the vertical miss distance of the measured target HB relative to the center of the first image are obtained; (x)_t2，y_t2) The horizontal miss distance and the vertical miss distance of the measured target HB relative to the center of the second image; alpha is alpha₁And alpha₂The method is an alternative process quantity in calculation and has no practical significance; f is the focal length of the first camera and the second camera when acquiring images, E₁Is the principle of the measured target HB relative to the first survey vessel C1Pitch angle, A₁Azimuth angle of measured object HB relative to first survey vessel C1, E₂Is the theoretical pitch angle, A, of the measured target HB relative to the second survey vessel C2₂Is the azimuth angle, theta, of the measured target HB relative to the second survey vessel C2₁Is a first angle theta₂Is the second included angle.

S5, according to the first included angle theta₁A second angle theta₂The geocentric rectangular coordinate (X) of the first survey vessel C1₁,Y₁,Z₁) The geocentric rectangular coordinate (X) of the second survey vessel C2₂,Y₂,Z₂) And the geocentric rectangular coordinates (X) of the cooperative target ship B3₃,Y₃,Z₃) And constructing a first cone intersection equation and a second cone intersection equation.

The first cone intersection equation and the second cone intersection equation are as follows:

wherein, (X, Y, Z) represents the geocentric rectangular coordinate of the measured target HB at the moment, and the coordinates are all unknown quantities to be solved.

S6, analyzing and rounding according to pixel points according to the first image and the second image to obtain the elevation H of the cooperative target ship B3_B3And height H of measured target HB_HBCombined with the geocentric rectangular coordinates (X) of the cooperative target ship B3₃,Y₃,Z₃) And establishing a spherical equation.

The elevation H of the cooperative target vessel B3 is known from the geodetic coordinates of the known cooperative target vessel B3_B3Combining the obtained first image and the second image which simultaneously comprise the cooperative target ship B3 and the measured target HB, taking the imaging centroids of the cooperative target ship B3 and the measured target HB in the image as specified target points, and estimating, rounding and calculating the elevation of the measured target HB according to the interval of pixel points of the two specified target points in the vertical direction in the imageH_HB。

In the embodiment of the invention, the elevation difference between the cooperative target ship B3 and the measured target HB is small relative to the radius of the earth, the influence on the overall calculation result is very little, and therefore, the elevation H of the measured target HB is calculated_HBAnd (4) manually combining the rough estimated value of the image to obtain the estimated value.

According to a space rectangular coordinate system, the earth is approximated to be a sphere, because the target HB to be measured and the cooperative target ship B3 are both positioned on the sea level, the landing point of the cooperative target ship B3 is closer to the landing point of the target HB to be measured, the circumference of the equator of the earth is about 40075 kilometers, and the circumference is far larger than the range tested on the sea level, therefore, the target HB to be measured and the cooperative target ship B3 can be approximated to be in one plane on the earth, the distances from the target HB to the globe center of the earth and the cooperative target ship B3 are approximately the same, namely, the distance from the target HB to be measured to the globe center of the earth is equal to the radius of the earth, and the spherical coordinate equation is satisfied. By utilizing the spherical coordinate equation, the external azimuth angle element of the camera which cannot be directly solved by the theodolite shaft angle encoder is abandoned, and the back intersection measurement mode of photogrammetry is simplified.

In order to reduce the error of the spherical coordinate equation, the height difference between the target HB to be measured and the cooperative target ship B3 should be removed.

The distance from the measured target HB (X, Y, Z) to the sphere center is as follows:

cooperative target ship B3 (X)₃,Y₃,Z₃) The distance to the center of the sphere is:

and (3) removing the height difference between the dynamic target HB and the cooperative target ship B3, wherein the spherical equation is as follows:

wherein, (X, Y, Z) represents the geocentric rectangular coordinate of the measured target HB at the moment, and the coordinates are all unknown quantities to be solved.

S7, according to the first cone intersection equation (1), the second cone intersection equation (2) and the spherical equation (3), respectively importing the geocentric rectangular coordinates (X) of the first survey vessel C1 corresponding to each time point₁,Y₁,Z₁) The geocentric rectangular coordinate (X) of the second survey vessel C2₂,Y₂,Z₂) Geocentric rectangular coordinates (X) of cooperative target ship B3₃,Y₃,Z₃) A first included angle theta₁A second angle theta₂Elevation H of cooperative target vessel B3_B3And height H of measured target HB_HBAnd constructing an iterative solution model, and calculating to obtain the geocentric rectangular coordinate of the measured target HB.

In the embodiment of the invention, the navigation distance of the selected cooperative target ship B3 is set, and in order to ensure the accuracy, the navigation distance of the selected cooperative target ship B3 is within 1 kilometer of the measured target HB. According to the principle of a measuring method, software Wolfram mathematica12 is used for traversing experimental data, data of each time period are processed, a first cone intersection equation (1), a second cone intersection equation (2) and a spherical equation (3) are set as constraint conditions, an iterative solution model is constructed, and the geocentric rectangular coordinate of a measured target HB is calculated.

And after the earth center rectangular coordinate of the target HB to be detected is obtained, the earth center rectangular coordinate can be converted into a station center coordinate. After the coordinates are converted into the station center coordinates, the position of the drop point of the measured target HB can be calibrated and recorded directly according to the position of the cooperative target ship B3.

Because the actual test may have the situation of large sea level wind waves, which causes the problem of image loss of the observation equipment, it is necessary to remove the unavailable voyage data and record more voyage data to ensure that the database is large enough. In actual measurement, data of two voyages of the round trip of the cooperative target ship B3 are measured generally by adopting different focal lengths f, and five voyages are adopted in engineering test in the embodiment of the invention to verify and calculate the centroid rectangular coordinate of the measured target HB.

In the embodiment of the invention, according to a plurality of ship running tests, unstable course factors are eliminated, unusable voyages are removed, individual unreasonable data are screened out in each group of usable voyages, at least 200 data are taken each time, the calculation result is compared with the actual known coordinate, and the probability that the error range of the calculated geocentric rectangular coordinate of the measured target HB is controlled within 5 meters is more than 75 percent, so the invention can be applied to the actual engineering test.

When the data obtained according to the embodiment of the invention, the falling point distance between the cooperative target ship B3 and the measured target HB is within the range of 200 meters, the error range can be reduced to be within 3 meters by the calculated coordinates, and the accuracy is higher. When the distance between the first measuring ship C1 and the second measuring ship C2 and the measured target HB is within 6 kilometers, through ship running tests, an image data set is adopted, and multiple tests verify that the falling point position accuracy of the measured target HB is within 5 meters. The camera system adopted by the embodiment of the invention should limit the distance between the first measuring ship C1 and the second measuring ship C2 relative to the measured target HB and the cooperative target ship B3 to be within 10 kilometers in consideration of shooting distance and the like.

In summary, the invention provides a method for measuring the position of an offshore target based on a cone angle intersection method. Firstly, the invention overcomes the problem that the Euler angle in the elements outside the camera cannot be solved directly by a theodolite shaft angle encoder when the theodolite is placed on a target ship platform, and solves the problem that the target landing point coordinate cannot be solved without satellite positioning assistance for an unknown target. Secondly, as the ship loaded with the theodolite shakes under the action of sea waves and sea winds, the tracking of the theodolite on a target is influenced, in the conventional scheme, a high-precision platform local reference system is required to be adopted for measuring three angles of yaw, pitch and roll generated by the ship shaking, and the measured data is processed and then transmitted to a servo tracking subsystem, so that the target is stably tracked without using a platform local reference. Meanwhile, when the photoelectric theodolite equipment is not available, the invention can adopt a camera to shoot, thereby simplifying the system and saving the cost. Finally, the invention simplifies the measurement mode of back intersection in the existing photogrammetry by using the cone intersection measurement method, and provides a simple, convenient and accurate measurement method for measuring the position of the target landing point on the sea.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be taken as limiting the invention. Variations, modifications, substitutions and alterations of the above-described embodiments may be made by those of ordinary skill in the art without departing from the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.