CN104360362B - Method and system for positioning observed object via aircraft - Google Patents

Abstract

The invention discloses a method for positioning an observed object. The method includes: acquiring object-targeted input data generated by an aircraft at every moment, wherein the input data include object image data and/or object ranging data; creating a sorting sequence by the input data; if two input data meeting preset conditions exist in the sorting sequence, using a first positioning algorithm for computing and outputting a positioning result, and otherwise, using a second positioning algorithm for computing and outputting the positioning result, wherein the first positioning algorithm is a two-point positioning method, the second positioning algorithm is an n-point positioning algorithm, and n is greater than or equal to 3. The invention further discloses a system for positioning the observed object. By the method and system, highly real-time and automatic positioning of the observed object can be realized.

Description

Method and system observed object being positioned using aircraft

Technical field

The invention belongs to observed object positioning field, it is related to a kind of method measured target being positioned using aircraft And system, particularly to the method and system using unmanned plane, target being observed and position.

Background technology

At present, no matter in military domain or civil area, the sector application of the unmanned plane of China all increasingly extends and deep Enter, such as military target search, petroleum pipeline monitoring, power-line patrolling, forestry fire prevention early warning, agricultural investigation etc..In these industries In application, unmanned plane, as a kind of extension of remote sensing application platform, gathers target information for responsible, for follow-up remote sensing number According to use, and the positioning of target information is to generate premise and the basis of available geographic information data.

The unmanned aerial vehicle remote sensing Target self-determination localization method commonly used at present mainly has based on reconnaissance platforms three-dimensional coordinate, video camera The target positioning of axial angle and terrain elevation data, the object localization method based on image sequence, be based on multiple image common ground Object localization method, the localization method being crossed based on photogrammetric front, the object localization method based on earth's surface coupling auxiliary Deng.

Target positioning based on reconnaissance platforms three-dimensional coordinate, video camera axial angle and terrain elevation data is traditional autonomous Positioning mode, determines, by the axial angle investigating position of platform and video camera, the orientation that target is located, and then utilizes digital elevation Information resolves the target three-dimensional coordinate under this orientation, and positioning precision is except by position error, the axial angle investigating platform (aircraft) Error impact is outer, also suffers from the precision impact of digital elevation model itself.

Based on the localization method of image sequence, be do not have in Reconnaissance system positioner or positioning occur rough error or even During inefficacy, in the case that control is extremely poor, complete target positioning by setting up collinearity condition equation degradation model, its Data basis also include digital topography map except investigation image.Its principle is by choosing on digital topography map and investigation image Control point of the same name, recovers, by collinear condition degeneration equation, attitude of photographing.Set up investigation image object and number on this basis The unified relationship of target on word topography, realizes target positioning.

Based on the object localization method of multiple image common ground, be using reconnaissance platforms obtain at least 3 two field pictures and these On image, the common ground information of at least more than 6 is improving the three-dimensional localization precision of ground target.This technology does not rely on shooting Machine axial angle and landform altitude information, eliminate two error sources in photogrammetric survey method, and investigation platform error becomes impact mesh The principal element of mark positioning precision.Its groundwork process is: the investigation platform equipped with gps/ins flies from target area overhead Cross, obtain a series of images, and ground control station will be reached under gps/ins data and view data, choose at least 3 frames on ground Non-colinear target area image, and therefrom determine at least 6 common ground, asks for target and common using three-dimensional coordinate computation model Three coordinates of point.

The localization method being crossed based on photogrammetric front, needs to be shot from multiple observation stations for target, utilizes Aircraft and the elements of exterior orientation of the position and attitude data calculating multiframe image of camera system, carry out handing in front of photogrammetric space Meeting, calculates the space coordinatess of impact point.

Based on the object localization method of earth's surface coupling auxiliary, in advance the flight being obtained using Aeronautics and Astronautics remote sensing Atural object image store below device is in ground-based computer supporting database.During the scope of fly past precalculated position, immediately measure Go out the atural object image of locality, measured drawing and reference map carry out relevant matches, you can obtain the position of aircraft.Location parameter obtains Purpose be support inertial navigation system, carry out position correction it is ensured that position resolve time space yardstick accuracy.

Summarize above localization method employed in unmanned plane it is found that existing method is mostly for single specific Data mode, using single data model, data source is calculated, but does not consider data acquisition during unmanned plane during flying Dynamic and complexity.And lack the optimization to data source it is impossible to realize the automatic selection of data source by algorithm.Further , in positioning, due to difficult to reach balance in terms of high accuracy and real-time, therefore, existing method is made to the pursuit of precision Become the disappearance of real-time, most methods are that the change to script artificial process uses, preferably at most a kind of ' quick ' calculating, and Non real-time.Meanwhile, the acquisition of positioning result also relies on outside geographic information data, such as elevation model, digital topography map etc., fixed The data precision of position result depends not only on observation error and is also limited to rely on data.

Accordingly, it would be desirable to a kind of real-time is high and measured target can be automatically positioned method.

Content of the invention

The present invention is in order to solve at least one problem above-mentioned and/or deficiency, and provides following at least one advantages.

On the one hand, there is provided a kind of aircraft observed object localization method, comprising:

Obtain the input data in each moment for target that aircraft produces, described input data includes target image Data and/or object ranging data；

Using described input data structural classification sequence；

If there is, in described sorting sequence, two described input datas meeting predetermined condition, using the first location algorithm Calculated and exported positioning result, otherwise, calculated using the second location algorithm and exported positioning result；Described first is fixed Position algorithm is two-point locating algorithm；Described second location algorithm is n point location algorithm, n >=3.

Further, also include: reversely calculate described aircraft and described target when current using described positioning result The relative cruising height data carved, and for correcting the relative cruising height data of the storage of current time.

Further, the constitution step of described sorting sequence includes:

Using One-Point Location algorithm, the input data in each moment described is calculated, obtain One-Point Location result；

If described One-Point Location result is unsatisfactory for default required precision, by the input data in this moment from described classification sequence Delete in row.

Further, described predetermined condition is, there are two input datas, and obtain this two institutes in described sorting sequence State the angle between the observation station of input data and described target to be more than 85 ° and be less than 95 °.

On the other hand, there is provided a kind of aircraft observed object alignment system, comprising:

Data acquisition module, for obtaining the input data that aircraft is directed to each moment of target, described input data Including destination image data and/or object ranging data；

Sequence structure module, for according to described input data structural classification sequence；

Positioning calculation module, for carrying out location Calculation simultaneously using the described input data in described sorting sequence to target Output positioning result；Wherein, if there is, in described sorting sequence, two described input datas meeting predetermined condition, utilize the One location algorithm is calculated and is exported positioning result, otherwise, is calculated using the second location algorithm and is exported positioning result； Described first location algorithm is two-point locating algorithm；Described second location algorithm is n point location algorithm, n >=3.

By present invention achieves being automatically positioned to observed object using input data, on the one hand, in position fixing process, By judging to the quality of data of input data, corresponding location algorithm can be selected to be calculated, no for judged result Only ensure that the effectiveness of target positioning result, and improve the positioning precision to target.In the position fixing process for target In, the cooperation of the first location algorithm and the second location algorithm can be always ensured that the result of target positioning within the acceptable range. Another side, the precision of the further input data of the present invention is screened, at any time delete be unsatisfactory for positioning requirements data it is ensured that The reliability in input data source.Another further aspect, using the positioning result producing cruising height data required to positioning etc. Parameter is updated and optimizes the correction it is achieved that to aircraft load data, it is to avoid the diffusion of the error being likely to occur.

Brief description

Fig. 1 is observed object alignment system schematic diagram in the embodiment of the present invention；

Fig. 2 is sequence structure module diagram in the embodiment of the present invention；

Fig. 3 is observed object localization method flow chart in the embodiment of the present invention；

Fig. 4 is data screening flow chart in the embodiment of the present invention.

Specific embodiment

Hereinafter, embodiments of the invention are described more fully with reference to the accompanying, shown in the drawings of the reality of the present invention Apply example.However, embodiments of the invention can be implemented in many different forms, and should originally not be considered limited to here row The embodiment going out.On the contrary, provide these exemplary embodiments so that the disclosure is thoroughly, and the scope of the present invention is filled Divide and convey to those skilled in the art, in the accompanying drawings, for clarity, layer and the size in region and relative chi can be exaggerated Very little.The detailed description to known function and structure will be omitted to avoid the subject matter of fuzzy embodiment.Identical in accompanying drawing Label is used for representing identical element.

The data that the present invention is applied to using aircraft obtains is positioned to target and is obtained positioning result.Can be for having People's aircraft or unmanned aerial vehicle, this aircraft is configured with the device for obtaining position of aircraft attitude and being used for obtain tested The video capturing device of target image and/or the range unit obtaining relative distance between aircraft and target.This aircraft and ground There is remote measurement transmission channel, for the data in aircraft is passed through this remote measurement transmission channel to ground between the control device of face Control device, and the calculating of target positioning is completed by GCU.

This aircraft can be in the form of unmanned plane in an embodiment, and unmanned plane belongs to unpiloted aircraft, thereon It is configured with the load of specific function, for, in flight course, completing observation mission.When being observed to target using unmanned plane Time, unmanned plane can be in flight course, and the camera with specific precision using configuration is imaged to target, thus can Obtain destination image data, meanwhile, if being also configured with range unit on this unmanned plane, can be further with range unit to quilt Survey target to be found range, thus obtaining the relative distance between unmanned plane and measured target.Unmanned plane utilizes the number acquired in load According to and various flying quality can be passed by telemeter channel, the positioning calculation process to target, by GCU according to The data receiving calculates and obtains.

As shown in figure 1, being unmanned plane observed object alignment system schematic diagram in the embodiment of the present invention.

With reference to Fig. 1, in this observed object alignment system, including data acquisition module, sequence structure module, positioning calculation mould Block.

Data acquisition module is used for obtaining the Various types of data that unmanned plane is passed down by telemeter channel, except for observed object Carry out outside all kinds of flying qualities of location Calculation, main inclusion in acquired data is not observed to target obtaining in the same time Destination image data and/or object ranging data.Because unmanned plane completes the observation to target in flight course, therefore, It is considered that as a rule, corresponding to not in the same time, the position of unmanned plane is also different.Equally, people in the art Member it is recognised that using a unmanned plane the data not obtained in the same time carry out location Calculation with using multiple unmanned planes or its The data that the aircraft of his type obtains in synchronization diverse location carries out location Calculation and has identical correlation.Right for realizing The acquisition through telemeter channel down-transmitting data for the unmanned plane, it is recognised that data acquisition module further with corresponding communication module Connected, after the data in telemeter channel being received and to be processed using communication module, exported data acquisition mould Block.

Sequence structure module is used for, on the basis of data acquisition module, first the input data obtaining being stored, This input data includes destination image data and/or object ranging data.Position the requirement of real-time for meeting target, can lead to Cross pre-set in sequence structure module storage maximal sequence length be configured, utilization can store 50 groups of input datas or Corresponding sequence length memory space is arranged according to specific system configuration and real-time demand.With further reference to Fig. 2, it is sequence Constructing module schematic diagram, in fig. 2, sequence structure module includes memory module data screening module, and memory module is used for depositing Storage input data simultaneously forms input data sorting sequence, and data screening module is sieved to the input data of storage in memory module Choosing, for proposing to meet the input data of positioning accuracy request, this data screening module screening process to input data Refer to described below.

Positioning calculation module carries out the positioning solution of target according to location algorithm using the sorting sequence in sequence structure module Calculate, thus obtaining and exporting target positioning result.In the embodiment of the present invention, can be using at least two positioning calculation algorithms to target Carry out location Calculation, in system normal course of operation, in sequence structure module, the data volume of storage meets predetermined quantity and wants When asking, and there is at least 2 input datas meeting predetermined condition, can preferentially using the first location algorithm, target be positioned Resolve, this first location algorithm is two-point locating algorithm.During positioning calculation, no longer exist and meet above-mentioned predetermined condition During 2 input datas, at least 3 in available sorting sequence position input datas, using the second location algorithm, target are entered Row location Calculation.Equally, when regaining, in sequence structure module, 2 input datas meeting predetermined condition, can be further Switch back into the first location algorithm and carry out positioning calculation using 2 input datas currently meeting predetermined condition.By using this two Plant location algorithm, real-time positioning can be carried out to target, the location condition set by the Computing Principle of this two kinds of algorithms and system can With reference to described below.

With further reference to Fig. 1, on the basis of above-mentioned each module, the system in this enforcement may also include reference data and updates Module, this module is in running status during the positioning calculation of system all the time, for entering to the current positioning result exporting Row reversely calculates, with the relative cruising height data using the relative cruising height data more row current time storage extrapolated, To ensure the required precision of the data satisfaction positioning used in positioning result process.

As Fig. 3, it is observed object localization method flow chart in the embodiment of the present invention.

With reference to Fig. 3, will be described in the flow process in the embodiment of the present invention, observed object being positioned.In step 301, The operation carrying out corresponding to data acquisition module, carries out classification to unmanned plane by the Various types of data that telemeter channel passes down and receives, And construct input data and export in sequence structure module.Preceding aim view data and/or object ranging is removed in input data Outside data, also include unmanned plane load data, the parameter of unmanned plane load data pack load sensor, load are relative to the appearance of aircraft The data such as state parameter.The attitude parameter of aircraft can be position and attitude data under the inertial coodinate system of local for the aircraft.Meanwhile, root According to one skilled in the art will appreciate that for completing to target positioning calculation, also needing to be previously entered or set unmanned plane gondola load Calibration information, it includes the focal length of imaging sensor, the size of imaging pixel, the distortion parameter of imaging sensor, aircraft ins Reference frame etc..For assisting each algorithm of final target positioning calculation, northeast sky coordinate system is used as aspect during positioning Inertial reference system, input or set aircraft ins reference frame purpose be to complete appearance between different coordinates in data input The conversion of state parameter.The attitude parameter of conversion includes course angle, roll angle and the angle of pitch of aircraft.

In step 302, construction is carried out by sequence structure module to input data and form sorting sequence, sorting sequence is root According to different pieces of information needed for variant algorithm, using memory module, list entries are stored.Input data removes target image number According to and/or object ranging data outside, corresponding to the first location algorithm (i.e. two-point locating algorithm), except needing each observation station to fly Machine course angleThe angle of pitch (θ) and roll angle (γ), the azimuth (a2) of gondola, the angle of pitch (α 2) and laser ranging away from From in addition it is also necessary to the relative position of aircraft is it is therefore desirable to storage unmanned plane is corresponding to the coordinate under two moment northeastward sky coordinate. Corresponding to the second location algorithm (i.e. n point location algorithm, n >=3), need the course angle of each observation station unmanned planeThe angle of pitch (θ) with roll angle (γ), the azimuth (a2) of gondola, angle of pitch (α 2) etc..

With further reference to Fig. 4, it is contemplated that data precision requires, using data screening flow process shown in Fig. 4 in position fixing process Figure, screens to the data in memory module in data screening module, and data screening module utilizes One-Point Location algorithm to every The input data in individual moment is calculated, and from the beginning of the acquisition of first input data from sorting sequence, requires full in data source When sufficient, persistently carry out backstage computing, the One-Point Location result of One-Point Location algorithm is stored in as follow-up data optimization Basis, judges to corresponding input data precision according to One-Point Location result simultaneously, if disclosure satisfy that default required precision, Then retain this input data, if default required precision can not be met, delete this input data in a storage module.

The method that One-Point Location algorithm adopts photogrammetric collinearity equation, this algorithm is by setting up the gps/ of aircraft and gondola Imu information and the transformational relation of sensing station attitude information in airphoto model, recover conllinear bar in photographic imagery model The parameter of part equation, by collinearity condition equation and terrain clearance information, recovers the coordinate information of target.

Collinearity condition equation is as follows:

$x=(z-z_s)\frac{a_1^{\′}(x-x_0)+a_2^{\′}(y-y_0)-a_3^{\′}f}{c_1^{\′}(x-x_0)+c_2^{\′}(y-y_0)-c_3^{\′}f}+x_s$

$y(z-z_s)\frac{b_1^{\′}(x-x_0)+b_2^{\′}(y-y_0)-b_3^{\′}f}{c_1^{\′}(x-x_0)+c_2^{\′}(y-y_0)-c_3^{\′}f}+y_s$

Each observation station imu information is the course angle of unmanned planeThe angle of pitch (θ) and roll angle (γ), the orientation of gondola Angle (a2), the angle of pitch (α 2).

a₁',a₂',a₃',b₁',b₂',b₃',c₁',c₂',c₃' be collinearity condition equation parameter, corresponding be matrix r= r₁·r₂Items, that is,

$r=\left[\begin{array}{ccc}{a_1}^{\′}& {a_2}^{\′}& {a_3}^{\′}\\ {b_1}^{\′}& {b_2}^{\′}& {b_3}^{\′}\\ {c_1}^{\′}& {c_2}^{\′}& {c_3}^{\′}\end{array}\right]=r_1\·r_2$

r₁、r₂As follows with the conversion relation of imu information:

$r_2=\left[\begin{array}{ccc}{\cos a}_2& {\cos \mathrm{\α}}_2{\sin a}_2& -{\sin \mathrm{\α}}_2{\sin a}_2\\ -{\sin a}_2& {\cos \mathrm{\α}}_2{\cos a}_2& -{\sin \mathrm{\α}}_2{\cos a}_2\\ 0& {\sin \mathrm{\α}}_2& {\cos \mathrm{\α}}_2\end{array}\right]$

When location data is for ranging information, collinearity equation is simplified, sets up equation as follows:

$\left[\begin{array}{c}x\\ y\\ z\end{array}\right]=r\·\left[\begin{array}{c}0\\ 0\\ -\mathrm{dis}\end{array}\right]=\left[\begin{array}{ccc}{a_1}^{\′}& {a_2}^{\′}& {a_3}^{\′}\\ {b_1}^{\′}& {b_2}^{\′}& {b_3}^{\′}\\ {c_1}^{\′}& {c_2}^{\′}& {c_3}^{\′}\end{array}\right]\·\left[\begin{array}{c}0\\ 0\\ -\mathrm{dis}\end{array}\right]$

Wherein dis is range finding distance, and x, y, z is target location coordinate.

With further reference to Fig. 3, in step 303, entered for measured target to adoptable by positioning calculation module first-selection Row location algorithm is judged, then, in step 304, carries out resolving obtaining to position using the target location algorithm determining and ties Really.Step 303 and step 304, after the completion of each positioning calculation, repeat.Wherein, in positioning calculation module, first is fixed Position algorithm is two-point locating algorithm, and the second location algorithm is 3 points and above location algorithm.

Corresponding to step 303, when in sorting sequence, there is two and two or more input data, and meet that to obtain this defeated The angle entering two lines between observation station and target of data is more than 45 ° and is less than 125 °, especially greater than 85 ° and be less than When 95 °, using two-point locating algorithm, for this location algorithm, it is dynamically fixed with many observation stations, multiframe that the embodiment of the present invention is adopted Position is different with One-Point Location mathematical model, and error simulation result is different, can effectively supplementing and correction as positioning result According to.

First location algorithm can be divided into 2 points of ranging localization algorithms and two field pictures according to whether comprising object ranging data Location algorithm.

In 2 points of ranging localization algorithms, location model obtains earth observation angle information first, in conjunction with ranging information and The position of observation station aircraft, completes the projection earthward of range laser light, calculates mesh by the joint of two range findings on ground Target locus.Earth observation angle information is calculated as ε by the attitude angle of aircraft and gondola:

ε=arccos (cos α₂cosγcosθ-cosa₂sinα₂sinγ+sina₂sinα₂cosγsinθ)

D=dis sin (ε)

ε combines aircraft position calculation after obtaining finds range the projection d on ground for the distance it is possible to intersection calculation target Geographical coordinates, this can be reduced to the problem of two circle intersection points on a same plane, and principle simply repeats no more here.

In two field pictures location algorithm, two field pictures positioning uses and 2 points of identical geometry location models that cross, but The calculating of observed bearing information is more complicated, except the attitude angle of aircraft and gondola also needs to consider image information.It is seen over the ground Measuring angle ε is:

$\mathrm{\ϵ}=\arccos \left(\frac{r_{31}\·x+r_{32}\·y+r_{33}\·(-f)}{-f}\right)$

D=hr tan (ε)

Wherein

$r=r_1\·r_2=\left[\begin{array}{ccc}{r}_{11}& r_{12}& r_{13}\\ r_{21}& r_{22}& r_{23}\\ r_{31}& r_{32}& r_{33}\end{array}\right]$

Hr is terrain clearance, i.e. the difference of the geodetic altitude of aircraft and target.

Here the calculating of dimensional information i.e. projector distance, because the range finding distance of aircraft and target, using observation station The terrain clearance of aircraft carries out trigonometric tangential and calculates acquisition.Thereafter resolve identical with ranging localization.

When in data ordered series of numbers, temporarily there is not satisfaction the first location algorithm required input data time, start the second positioning Algorithm, when in the second location algorithm requirement categorical data sequence, input data number is than or equal to three.I.e. when presence three Or during more than three input datas, the second location algorithm of employing is more than three frames and three frames dynamic positioning location algorithm, this calculation The sky three that method relies on multiple aerial observation data resolves, and carries out Real-time and Dynamic adjustment, the light path of every frame when calculating photography first

${\hat{v}}_j=r_j^{-1}{x}_j$

Wherein r_jIt is the comprehensive spin matrix pointing out unmanned plane and gondola in j-th observation, with above mentioned single frames meter Calculation mode is consistent.x_jFor the target location on j-th observation station picture frame.Positioning can be reduced to ask from all light path of photography Near optimum point, using least-squares calculation.Optimal value p is:

$p={\left[\underset{j}{\mathrm{\σ}}(i-{\hat{v}}_j{{\hat{v}}_j}^t)\right]}^{-1}\left[\underset{j}{\mathrm{\σ}}(i-{\hat{v}}_j{{\hat{v}}_j}^t)c_j\right]$

c_jIt is the photocentre position of photography load in unmanned plane gondola, the locus of aircraft can be reduced to, i is a list Bit matrix.

Location data is 3 points and above distance measuring type location Calculation of range finding, actually calculates the friendship of multiple Spatial Spheres Point, clearly, its solution formula repeats no more mathematical principle here.

Positioning result to the target obtaining through above-mentioned algorithm, carries out Coordinate Conversion further, for example will be in real-time bar Target positioning result under the inertial coodinate system obtaining under part, is scaled to unmanned plane positioning earth coordinates used, and in real time Export to terminal.

Corresponding to the global position system different from unmanned plane, the such as Big Dipper, gps, glonass etc., localization method can prop up Hold the conversion between different geodetic coordinates converting system intrinsic coordinates conversion Calculation and earth coordinates.

Above-mentioned algorithm or system can be stored in the internal memory of GCU individual according to the configuration of GCU, And after being called by the arithmetic element of GCU, response input data is read out, thus completing to target Status.

Although illustrate and describing the present invention with reference to only certain embodiments of the present invention, those skilled in the art will Understand: in the case of without departing from the spirit and scope of the present invention being defined by the claims, form and thin can be made wherein The various changes of section aspect.

Claims (6)

1. a kind of observed object localization method is it is characterised in that include:

Obtain the input data in each moment for target that aircraft produces, described input data includes destination image data And/or object ranging data；

Using described input data structural classification sequence；

If there is, in described sorting sequence, two described input datas meeting predetermined condition, carried out using the first location algorithm Calculate and export positioning result, otherwise, calculated using the second location algorithm and exported positioning result；Described first positioning is calculated Method is two-point locating algorithm；Described second location algorithm is n point location algorithm, n >=3；

The constitution step of described sorting sequence includes:

Using One-Point Location algorithm, the input data in each moment described is calculated, obtain One-Point Location result；

If described One-Point Location result is unsatisfactory for default required precision, by the input data in this moment from described sorting sequence Delete.

2. method as claimed in claim 1 is it is characterised in that also include: reversely calculates described flight using described positioning result Device and described target in the relative cruising height data of current time, and for correcting the relative navigation height of the storage of current time Degrees of data.

3., it is characterised in that described predetermined condition is, in described sorting sequence, presence two is defeated for method as claimed in claim 1 Enter data, and the angle obtaining between the observation station of this two described input datas and described target is more than 85 ° and is less than 95 °.

4. a kind of aircraft observed object alignment system is it is characterised in that include:

Data acquisition module, for obtaining the input data that aircraft is directed to each moment of target, described input data includes Destination image data and/or object ranging data；

Sequence structure module, for according to described input data structural classification sequence；

Positioning calculation module, for carrying out location Calculation using the described input data in described sorting sequence to target and exporting Positioning result；Wherein, if there is, in described sorting sequence, two described input datas meeting predetermined condition, fixed using first Position algorithm is calculated and is exported positioning result, otherwise, is calculated using the second location algorithm and is exported positioning result；Described First location algorithm is two-point locating algorithm；Described second location algorithm is n point location algorithm, n >=3；

Described sequence structure module includes, memory module data screening module, and described memory module, for storing described input Data；Described data screening module is calculated to the input data in each moment described using One-Point Location algorithm, and obtains One-Point Location result；If described One-Point Location result is unsatisfactory for default required precision, by the input data in this moment from described Delete in memory module.

5. system as claimed in claim 4 is it is characterised in that reference data update module, for anti-according to described positioning result To calculating the described aircraft and described target relative cruising height data in current time, and it is used for correcting depositing of current time The relative cruising height data of storage.

6. system as claimed in claim 4 is it is characterised in that described predetermined condition is to have two in described sequence structure module Input data, and the angle obtaining between the observation station of this two described input datas and described target is more than 85 ° and less than 95 °.